debian conntrack 0.9.14-2

14 files changed, 2477 insertions, 0 deletions

diff --git a/doc/sync/alarm/README b/doc/sync/alarm/README
new file mode 100644
index 0000000..dfd8474
--- /dev/null
+++ b/doc/sync/alarm/README
@@ -0,0 +1 @@
+This directory contains the files for the ALARM based protocol
diff --git a/doc/sync/alarm/conntrackd.conf b/doc/sync/alarm/conntrackd.conf
new file mode 100644
index 0000000..3424e39
--- /dev/null
+++ b/doc/sync/alarm/conntrackd.conf
@@ -0,0 +1,372 @@
+#
+# Synchronizer settings
+#
+Sync {
+	Mode ALARM {
+		#
+		# If a conntrack entry is not modified in <= 15 seconds, then
+		# a message is broadcasted. This mechanism is used to
+		# resynchronize nodes that just joined the multicast group
+		#
+		RefreshTime 15
+	
+		#
+		# If we don't receive a notification about the state of 
+		# an entry in the external cache after N seconds, then
+		# remove it.
+		#
+		CacheTimeout 180
+
+		#
+		# This parameter allows you to set an initial fixed timeout
+		# for the committed entries when this node goes from backup
+		# to primary. This mechanism provides a way to purge entries
+		# that were not recovered appropriately after the specified
+		# fixed timeout. If you set a low value, TCP entries in
+		# Established states with no traffic may hang. For example,
+		# an SSH connection without KeepAlive enabled. If not set,
+		# the daemon uses an approximate timeout value calculation
+		# mechanism. By default, this option is not set.
+		#
+		# CommitTimeout 180
+
+		#
+		# If the firewall replica goes from primary to backup,
+		# the conntrackd -t command is invoked in the script. 
+		# This command schedules a flush of the table in N seconds.
+		# This is useful to purge the connection tracking table of
+		# zombie entries and avoid clashes with old entries if you
+		# trigger several consecutive hand-overs. Default is 60 seconds
+		#
+		# PurgeTimeout 60
+	}
+
+	#
+	# Multicast IP and interface where messages are
+	# broadcasted (dedicated link). IMPORTANT: Make sure
+	# that iptables accepts traffic for destination
+	# 225.0.0.50, eg:
+	#
+	#	iptables -I INPUT -d 225.0.0.50 -j ACCEPT
+	#	iptables -I OUTPUT -d 225.0.0.50 -j ACCEPT
+	#
+	Multicast {
+		# 
+		# Multicast address: The address that you use as destination
+		# in the synchronization messages. You do not have to add
+		# this IP to any of your existing interfaces. If any doubt,
+		# do not modify this value.
+		#
+		IPv4_address 225.0.0.50
+
+		#
+		# The multicast group that identifies the cluster. If any
+		# doubt, do not modify this value.
+		#
+		Group 3780
+
+		#
+		# IP address of the interface that you are going to use to
+		# send the synchronization messages. Remember that you must
+		# use a dedicated link for the synchronization messages.
+		#
+		IPv4_interface 192.168.100.100
+
+		#
+		# The name of the interface that you are going to use to
+		# send the synchronization messages.
+		#
+		Interface eth2
+
+		# The multicast sender uses a buffer to enqueue the packets
+		# that are going to be transmitted. The default size of this
+		# socket buffer is available at /proc/sys/net/core/wmem_default.
+		# This value determines the chances to have an overrun in the
+		# sender queue. The overrun results packet loss, thus, losing
+		# state information that would have to be retransmitted. If you
+		# notice some packet loss, you may want to increase the size
+		# of the sender buffer. The default size is usually around
+		# ~100 KBytes which is fairly small for busy firewalls.
+		#
+		SndSocketBuffer 1249280
+
+		# The multicast receiver uses a buffer to enqueue the packets
+		# that the socket is pending to handle. The default size of this
+		# socket buffer is available at /proc/sys/net/core/rmem_default.
+		# This value determines the chances to have an overrun in the
+		# receiver queue. The overrun results packet loss, thus, losing
+		# state information that would have to be retransmitted. If you
+		# notice some packet loss, you may want to increase the size of
+		# the receiver buffer. The default size is usually around
+		# ~100 KBytes which is fairly small for busy firewalls.
+		#
+		RcvSocketBuffer 1249280
+
+		# 
+		# Enable/Disable message checksumming. This is a good
+		# property to achieve fault-tolerance. In case of doubt, do
+		# not modify this value.
+		#
+		Checksum on
+	}
+	#
+	# You can specify more than one dedicated link. Thus, if one dedicated
+	# link fails, conntrackd can fail-over to another. Note that adding
+	# more than one dedicated link does not mean that state-updates will
+	# be sent to all of them. There is only one active dedicated link at
+	# a given moment. The `Default' keyword indicates that this interface
+	# will be selected as the initial dedicated link. You can have 
+	# up to 4 redundant dedicated links. Note: Use different multicast 
+	# groups for every redundant link.
+	#
+	# Multicast Default {
+	#	IPv4_address 225.0.0.51
+	#	Group 3781
+	#	IPv4_interface 192.168.100.101
+	#	Interface eth3
+	#	# SndSocketBuffer 1249280
+	#	# RcvSocketBuffer 1249280
+	#	Checksum on
+	# }
+
+	#
+	# You can use Unicast UDP instead of Multicast to propagate events.
+	# Note that you cannot use unicast UDP and Multicast at the same
+	# time, you can only select one.
+	# 
+	# UDP {
+		# 
+		# UDP address that this firewall uses to listen to events.
+		#
+		# IPv4_address 192.168.2.100
+		#
+		# or you may want to use an IPv6 address:
+		#
+		# IPv6_address fe80::215:58ff:fe28:5a27
+
+		#
+		# Destination UDP address that receives events, ie. the other
+		# firewall's dedicated link address.
+		#
+		# IPv4_Destination_Address 192.168.2.101
+		#
+		# or you may want to use an IPv6 address:
+		#
+		# IPv6_Destination_Address fe80::2d0:59ff:fe2a:775c
+
+		#
+		# UDP port used
+		#
+		# Port 3780
+
+		#
+		# The name of the interface that you are going to use to
+		# send the synchronization messages.
+		#
+		# Interface eth2
+
+		# 
+		# The sender socket buffer size
+		#
+		# SndSocketBuffer 1249280
+
+		#
+		# The receiver socket buffer size
+		#
+		# RcvSocketBuffer 1249280
+
+		# 
+		# Enable/Disable message checksumming. 
+		#
+		# Checksum on
+	# }
+}
+
+#
+# General settings
+#
+General {
+	#
+	# Set the nice value of the daemon, this value goes from -20
+	# (most favorable scheduling) to 19 (least favorable). Using a
+	# very low value reduces the chances to lose state-change events.
+	# Default is 0 but this example file sets it to most favourable
+	# scheduling as this is generally a good idea. See man nice(1) for
+	# more information.
+	#
+	Nice -20
+
+	#
+	# Select a different scheduler for the daemon, you can select between
+	# RR and FIFO and the process priority (minimum is 0, maximum is 99).
+	# See man sched_setscheduler(2) for more information. Using a RT
+	# scheduler reduces the chances to overrun the Netlink buffer.
+	#
+	# Scheduler {
+	#	Type FIFO
+	#	Priority 99
+	# }
+
+	#
+	# Number of buckets in the cache hashtable. The bigger it is,
+	# the closer it gets to O(1) at the cost of consuming more memory.
+	# Read some documents about tuning hashtables for further reference.
+	#
+	HashSize 32768
+
+	#
+	# Maximum number of conntracks, it should be double of: 
+	# $ cat /proc/sys/net/netfilter/nf_conntrack_max
+	# since the daemon may keep some dead entries cached for possible
+	# retransmission during state synchronization.
+	#
+	HashLimit 131072
+
+	#
+	# Logfile: on (/var/log/conntrackd.log), off, or a filename
+	# Default: off
+	#
+	LogFile on
+
+	#
+	# Syslog: on, off or a facility name (daemon (default) or local0..7)
+	# Default: off
+	#
+	#Syslog on
+
+	#
+	# Lockfile
+	# 
+	LockFile /var/lock/conntrack.lock
+
+	#
+	# Unix socket configuration
+	#
+	UNIX {
+		Path /var/run/conntrackd.ctl
+		Backlog 20
+	}
+
+	#
+	# Netlink event socket buffer size. If you do not specify this clause,
+	# the default buffer size value in /proc/net/core/rmem_default is
+	# used. This default value is usually around 100 Kbytes which is
+	# fairly small for busy firewalls. This leads to event message dropping
+	# and high CPU consumption. This example configuration file sets the
+	# size to 2 MBytes to avoid this sort of problems.
+	#
+	NetlinkBufferSize 2097152
+
+	#
+	# The daemon doubles the size of the netlink event socket buffer size
+	# if it detects netlink event message dropping. This clause sets the
+	# maximum buffer size growth that can be reached. This example file
+	# sets the size to 8 MBytes.
+	#
+	NetlinkBufferSizeMaxGrowth 8388608
+
+	#
+	# If the daemon detects that Netlink is dropping state-change events,
+	# it automatically schedules a resynchronization against the Kernel
+	# after 30 seconds (default value). Resynchronizations are expensive
+	# in terms of CPU consumption since the daemon has to get the full
+	# kernel state-table and purge state-entries that do not exist anymore.
+	# Be careful of setting a very small value here. You have the following
+	# choices: On (enabled, use default 30 seconds value), Off (disabled)
+	# or Value (in seconds, to set a specific amount of time). If not
+	# specified, the daemon assumes that this option is enabled.
+	#
+	# NetlinkOverrunResync On
+
+	# If you want reliable event reporting over Netlink, set on this
+	# option. If you set on this clause, it is a good idea to set off
+	# NetlinkOverrunResync. This option is off by default and you need
+	# a Linux kernel >= 2.6.31.
+	#
+	# NetlinkEventsReliable Off
+
+	# 
+	# By default, the daemon receives state updates following an
+	# event-driven model. You can modify this behaviour by switching to
+	# polling mode with the PollSecs clause. This clause tells conntrackd
+	# to dump the states in the kernel every N seconds. With regards to
+	# synchronization mode, the polling mode can only guarantee that
+	# long-lifetime states are recovered. The main advantage of this method
+	# is the reduction in the state replication at the cost of reducing the
+	# chances of recovering connections.
+	#
+	# PollSecs 15
+
+	#
+	# The daemon prioritizes the handling of state-change events coming
+	# from the core. With this clause, you can set the maximum number of
+	# state-change events (those coming from kernel-space) that the daemon
+	# will handle after which it will handle other events coming from the
+	# network or userspace. A low value improves interactivity (in terms of
+	# real-time behaviour) at the cost of extra CPU consumption.
+	# Default (if not set) is 100.
+	#
+	# EventIterationLimit 100
+
+	#
+	# Event filtering: This clause allows you to filter certain traffic,
+	# There are currently three filter-sets: Protocol, Address and
+	# State. The filter is attached to an action that can be: Accept or
+	# Ignore. Thus, you can define the event filtering policy of the
+	# filter-sets in positive or negative logic depending on your needs.
+	# You can select if conntrackd filters the event messages from 
+	# user-space or kernel-space. The kernel-space event filtering
+	# saves some CPU cycles by avoiding the copy of the event message
+	# from kernel-space to user-space. The kernel-space event filtering
+	# is prefered, however, you require a Linux kernel >= 2.6.29 to
+	# filter from kernel-space. If you want to select kernel-space 
+	# event filtering, use the keyword 'Kernelspace' instead of 
+	# 'Userspace'.
+	#
+	Filter From Userspace {
+		#
+		# Accept only certain protocols: You may want to replicate
+		# the state of flows depending on their layer 4 protocol.
+		#
+		Protocol Accept {
+			TCP
+			SCTP
+			DCCP
+			# ICMP # This requires a Linux kernel >= 2.6.31
+		}
+
+		#
+		# Ignore traffic for a certain set of IP's: Usually all the
+		# IP assigned to the firewall since local traffic must be
+		# ignored, only forwarded connections are worth to replicate.
+		# Note that these values depends on the local IPs that are
+		# assigned to the firewall.
+		#
+		Address Ignore {
+			IPv4_address 127.0.0.1 # loopback
+			IPv4_address 192.168.0.100 # virtual IP 1
+			IPv4_address 192.168.1.100 # virtual IP 2
+			IPv4_address 192.168.0.1
+			IPv4_address 192.168.1.1
+			IPv4_address 192.168.100.100 # dedicated link ip
+			#
+			# You can also specify networks in format IP/cidr.
+			# IPv4_address 192.168.0.0/24
+			#
+			# You can also specify an IPv6 address
+			# IPv6_address ::1
+		}
+
+		#
+		# Uncomment this line below if you want to filter by flow state.
+		# This option introduces a trade-off in the replication: it
+		# reduces CPU consumption at the cost of having lazy backup 
+		# firewall replicas. The existing TCP states are: SYN_SENT,
+		# SYN_RECV, ESTABLISHED, FIN_WAIT, CLOSE_WAIT, LAST_ACK,
+		# TIME_WAIT, CLOSED, LISTEN.
+		#
+		# State Accept {
+		#	ESTABLISHED CLOSED TIME_WAIT CLOSE_WAIT for TCP
+		# }
+	}
+}
diff --git a/doc/sync/alarm/conntrackd.conf.orig b/doc/sync/alarm/conntrackd.conf.orig
new file mode 100644
index 0000000..ca6e661
--- /dev/null
+++ b/doc/sync/alarm/conntrackd.conf.orig
@@ -0,0 +1,348 @@
+#
+# Synchronizer settings
+#
+Sync {
+	Mode ALARM {
+		#
+		# If a conntrack entry is not modified in <= 15 seconds, then
+		# a message is broadcasted. This mechanism is used to
+		# resynchronize nodes that just joined the multicast group
+		#
+		RefreshTime 15
+	
+		#
+		# If we don't receive a notification about the state of 
+		# an entry in the external cache after N seconds, then
+		# remove it.
+		#
+		CacheTimeout 180
+
+		#
+		# This parameter allows you to set an initial fixed timeout
+		# for the committed entries when this node goes from backup
+		# to primary. This mechanism provides a way to purge entries
+		# that were not recovered appropriately after the specified
+		# fixed timeout. If you set a low value, TCP entries in
+		# Established states with no traffic may hang. For example,
+		# an SSH connection without KeepAlive enabled. If not set,
+		# the daemon uses an approximate timeout value calculation
+		# mechanism. By default, this option is not set.
+		#
+		# CommitTimeout 180
+
+		#
+		# If the firewall replica goes from primary to backup,
+		# the conntrackd -t command is invoked in the script. 
+		# This command schedules a flush of the table in N seconds.
+		# This is useful to purge the connection tracking table of
+		# zombie entries and avoid clashes with old entries if you
+		# trigger several consecutive hand-overs. Default is 60 seconds
+		#
+		# PurgeTimeout 60
+	}
+
+	#
+	# Multicast IP and interface where messages are
+	# broadcasted (dedicated link). IMPORTANT: Make sure
+	# that iptables accepts traffic for destination
+	# 225.0.0.50, eg:
+	#
+	#	iptables -I INPUT -d 225.0.0.50 -j ACCEPT
+	#	iptables -I OUTPUT -d 225.0.0.50 -j ACCEPT
+	#
+	Multicast {
+		# 
+		# Multicast address: The address that you use as destination
+		# in the synchronization messages. You do not have to add
+		# this IP to any of your existing interfaces. If any doubt,
+		# do not modify this value.
+		#
+		IPv4_address 225.0.0.50
+
+		#
+		# The multicast group that identifies the cluster. If any
+		# doubt, do not modify this value.
+		#
+		Group 3780
+
+		#
+		# IP address of the interface that you are going to use to
+		# send the synchronization messages. Remember that you must
+		# use a dedicated link for the synchronization messages.
+		#
+		IPv4_interface 192.168.100.100
+
+		#
+		# The name of the interface that you are going to use to
+		# send the synchronization messages.
+		#
+		Interface eth2
+
+		# The multicast sender uses a buffer to enqueue the packets
+		# that are going to be transmitted. The default size of this
+		# socket buffer is available at /proc/sys/net/core/wmem_default.
+		# This value determines the chances to have an overrun in the
+		# sender queue. The overrun results packet loss, thus, losing
+		# state information that would have to be retransmitted. If you
+		# notice some packet loss, you may want to increase the size
+		# of the sender buffer. The default size is usually around
+		# ~100 KBytes which is fairly small for busy firewalls.
+		#
+		SndSocketBuffer 1249280
+
+		# The multicast receiver uses a buffer to enqueue the packets
+		# that the socket is pending to handle. The default size of this
+		# socket buffer is available at /proc/sys/net/core/rmem_default.
+		# This value determines the chances to have an overrun in the
+		# receiver queue. The overrun results packet loss, thus, losing
+		# state information that would have to be retransmitted. If you
+		# notice some packet loss, you may want to increase the size of
+		# the receiver buffer. The default size is usually around
+		# ~100 KBytes which is fairly small for busy firewalls.
+		#
+		RcvSocketBuffer 1249280
+
+		# 
+		# Enable/Disable message checksumming. This is a good
+		# property to achieve fault-tolerance. In case of doubt, do
+		# not modify this value.
+		#
+		Checksum on
+	}
+	#
+	# You can specify more than one dedicated link. Thus, if one dedicated
+	# link fails, conntrackd can fail-over to another. Note that adding
+	# more than one dedicated link does not mean that state-updates will
+	# be sent to all of them. There is only one active dedicated link at
+	# a given moment. The `Default' keyword indicates that this interface
+	# will be selected as the initial dedicated link. You can have 
+	# up to 4 redundant dedicated links. Note: Use different multicast 
+	# groups for every redundant link.
+	#
+	# Multicast Default {
+	#	IPv4_address 225.0.0.51
+	#	Group 3781
+	#	IPv4_interface 192.168.100.101
+	#	Interface eth3
+	#	# SndSocketBuffer 1249280
+	#	# RcvSocketBuffer 1249280
+	#	Checksum on
+	# }
+
+	#
+	# You can use Unicast UDP instead of Multicast to propagate events.
+	# Note that you cannot use unicast UDP and Multicast at the same
+	# time, you can only select one.
+	# 
+	# UDP {
+		# 
+		# UDP address that this firewall uses to listen to events.
+		#
+		# IPv4_address 192.168.2.100
+		#
+		# or you may want to use an IPv6 address:
+		#
+		# IPv6_address fe80::215:58ff:fe28:5a27
+
+		#
+		# Destination UDP address that receives events, ie. the other
+		# firewall's dedicated link address.
+		#
+		# IPv4_Destination_Address 192.168.2.101
+		#
+		# or you may want to use an IPv6 address:
+		#
+		# IPv6_Destination_Address fe80::2d0:59ff:fe2a:775c
+
+		#
+		# UDP port used
+		#
+		# Port 3780
+
+		#
+		# The name of the interface that you are going to use to
+		# send the synchronization messages.
+		#
+		# Interface eth2
+
+		# 
+		# The sender socket buffer size
+		#
+		# SndSocketBuffer 1249280
+
+		#
+		# The receiver socket buffer size
+		#
+		# RcvSocketBuffer 1249280
+
+		# 
+		# Enable/Disable message checksumming. 
+		#
+		# Checksum on
+	# }
+}
+
+#
+# General settings
+#
+General {
+	#
+	# Set the nice value of the daemon, this value goes from -20
+	# (most favorable scheduling) to 19 (least favorable). Using a
+	# very low value reduces the chances to lose state-change events.
+	# Default is 0 but this example file sets it to most favourable
+	# scheduling as this is generally a good idea. See man nice(1) for
+	# more information.
+	#
+	Nice -20
+
+	#
+	# Number of buckets in the cache hashtable. The bigger it is,
+	# the closer it gets to O(1) at the cost of consuming more memory.
+	# Read some documents about tuning hashtables for further reference.
+	#
+	HashSize 32768
+
+	#
+	# Maximum number of conntracks, it should be double of: 
+	# $ cat /proc/sys/net/netfilter/nf_conntrack_max
+	# since the daemon may keep some dead entries cached for possible
+	# retransmission during state synchronization.
+	#
+	HashLimit 131072
+
+	#
+	# Logfile: on (/var/log/conntrackd.log), off, or a filename
+	# Default: off
+	#
+	LogFile on
+
+	#
+	# Syslog: on, off or a facility name (daemon (default) or local0..7)
+	# Default: off
+	#
+	#Syslog on
+
+	#
+	# Lockfile
+	# 
+	LockFile /var/lock/conntrack.lock
+
+	#
+	# Unix socket configuration
+	#
+	UNIX {
+		Path /var/run/conntrackd.ctl
+		Backlog 20
+	}
+
+	#
+	# Netlink event socket buffer size. If you do not specify this clause,
+	# the default buffer size value in /proc/net/core/rmem_default is
+	# used. This default value is usually around 100 Kbytes which is
+	# fairly small for busy firewalls. This leads to event message dropping
+	# and high CPU consumption. This example configuration file sets the
+	# size to 2 MBytes to avoid this sort of problems.
+	#
+	NetlinkBufferSize 2097152
+
+	#
+	# The daemon doubles the size of the netlink event socket buffer size
+	# if it detects netlink event message dropping. This clause sets the
+	# maximum buffer size growth that can be reached. This example file
+	# sets the size to 8 MBytes.
+	#
+	NetlinkBufferSizeMaxGrowth 8388608
+
+	#
+	# If the daemon detects that Netlink is dropping state-change events,
+	# it automatically schedules a resynchronization against the Kernel
+	# after 30 seconds (default value). Resynchronizations are expensive
+	# in terms of CPU consumption since the daemon has to get the full
+	# kernel state-table and purge state-entries that do not exist anymore.
+	# Be careful of setting a very small value here. You have the following
+	# choices: On (enabled, use default 30 seconds value), Off (disabled)
+	# or Value (in seconds, to set a specific amount of time). If not
+	# specified, the daemon assumes that this option is enabled.
+	#
+	# NetlinkOverrunResync On
+
+	# 
+	# By default, the daemon receives state updates following an
+	# event-driven model. You can modify this behaviour by switching to
+	# polling mode with the PollSecs clause. This clause tells conntrackd
+	# to dump the states in the kernel every N seconds. With regards to
+	# synchronization mode, the polling mode can only guarantee that
+	# long-lifetime states are recovered. The main advantage of this method
+	# is the reduction in the state replication at the cost of reducing the
+	# chances of recovering connections.
+	#
+	# PollSecs 15
+
+	#
+	# The daemon prioritizes the handling of state-change events coming
+	# from the core. With this clause, you can set the maximum number of
+	# state-change events (those coming from kernel-space) that the daemon
+	# will handle after which it will handle other events coming from the
+	# network or userspace. A low value improves interactivity (in terms of
+	# real-time behaviour) at the cost of extra CPU consumption.
+	# Default (if not set) is 100.
+	#
+	# EventIterationLimit 100
+
+	#
+	# Event filtering: This clause allows you to filter certain traffic,
+	# There are currently three filter-sets: Protocol, Address and
+	# State. The filter is attached to an action that can be: Accept or
+	# Ignore. Thus, you can define the event filtering policy of the
+	# filter-sets in positive or negative logic depending on your needs.
+	# You can select if conntrackd filters the event messages from 
+	# user-space or kernel-space. The kernel-space event filtering
+	# saves some CPU cycles by avoiding the copy of the event message
+	# from kernel-space to user-space. The kernel-space event filtering
+	# is prefered, however, you require a Linux kernel >= 2.6.29 to
+	# filter from kernel-space. If you want to select kernel-space 
+	# event filtering, use the keyword 'Kernelspace' instead of 
+	# 'Userspace'.
+	#
+	Filter From Userspace {
+		#
+		# Accept only certain protocols: You may want to replicate
+		# the state of flows depending on their layer 4 protocol.
+		#
+		Protocol Accept {
+			TCP
+		}
+
+		#
+		# Ignore traffic for a certain set of IP's: Usually all the
+		# IP assigned to the firewall since local traffic must be
+		# ignored, only forwarded connections are worth to replicate.
+		# Note that these values depends on the local IPs that are
+		# assigned to the firewall.
+		#
+		Address Ignore {
+			IPv4_address 127.0.0.1 # loopback
+			IPv4_address 192.168.0.100 # virtual IP 1
+			IPv4_address 192.168.1.100 # virtual IP 2
+			IPv4_address 192.168.0.1
+			IPv4_address 192.168.1.1
+			IPv4_address 192.168.100.100 # dedicated link ip
+			#
+			# You can also specify networks in format IP/cidr.
+			# IPv4_address 192.168.0.0/24
+		}
+
+		#
+		# Uncomment this line below if you want to filter by flow state.
+		# This option introduces a trade-off in the replication: it
+		# reduces CPU consumption at the cost of having lazy backup 
+		# firewall replicas. The existing TCP states are: SYN_SENT,
+		# SYN_RECV, ESTABLISHED, FIN_WAIT, CLOSE_WAIT, LAST_ACK,
+		# TIME_WAIT, CLOSED, LISTEN.
+		#
+		# State Accept {
+		#	ESTABLISHED CLOSED TIME_WAIT CLOSE_WAIT for TCP
+		# }
+	}
+}
diff --git a/doc/sync/alarm/conntrackd.conf.rej b/doc/sync/alarm/conntrackd.conf.rej
new file mode 100644
index 0000000..108546f
--- /dev/null
+++ b/doc/sync/alarm/conntrackd.conf.rej
@@ -0,0 +1,30 @@
+*************** Sync {
+*** 23,36 ****
+  
+  		#
+  		# If the firewall replica goes from primary to backup,
+- 		# the conntrackd -t command is invoked in the script. 
+- 		# This command resets the timers of the conntracks that
+- 		# live in the kernel to this new value. This is useful
+- 		# to purge the connection tracking table of zombie entries
+- 		# and avoid clashes with old entries if you trigger 
+- 		# several consecutive hand-overs.
+  		#
+- 		PurgeTimeout 15
+  
+  		# Set the acknowledgement window size. If you decrease this
+  		# value, the number of acknowlegdments increases. More
+--- 23,35 ----
+  
+  		#
+  		# If the firewall replica goes from primary to backup,
++ 		# the conntrackd -t command is invoked in the script.
++ 		# This command schedules a flush of the table in N seconds.
++ 		# This is useful to purge the connection tracking table of
++ 		# zombie entries and avoid clashes with old entries if you
++ 		# trigger several consecutive hand-overs. Default is 60 seconds.
+  		#
++ 		# PurgeTimeout 60
+  
+  		# Set the acknowledgement window size. If you decrease this
+  		# value, the number of acknowlegdments increases. More
diff --git a/doc/sync/ftfw/README b/doc/sync/ftfw/README
new file mode 100644
index 0000000..a09db10
--- /dev/null
+++ b/doc/sync/ftfw/README
@@ -0,0 +1 @@
+This directory contains the files for the FT-FW based protocol
diff --git a/doc/sync/ftfw/conntrackd.conf b/doc/sync/ftfw/conntrackd.conf
new file mode 100644
index 0000000..df10aca
--- /dev/null
+++ b/doc/sync/ftfw/conntrackd.conf
@@ -0,0 +1,397 @@
+#
+# Synchronizer settings
+#
+Sync {
+	Mode FTFW {
+		#
+		# Size of the resend queue (in objects). This is the maximum
+		# number of objects that can be stored waiting to be confirmed
+		# via acknoledgment. If you keep this value low, the daemon
+		# will have less chances to recover state-changes under message
+		# omission. On the other hand, if you keep this value high,
+		# the daemon will consume more memory to store dead objects.
+		# Default is 131072 objects.
+		#
+		# ResendQueueSize 131072
+
+		#
+		# This parameter allows you to set an initial fixed timeout
+		# for the committed entries when this node goes from backup
+		# to primary. This mechanism provides a way to purge entries
+		# that were not recovered appropriately after the specified
+		# fixed timeout. If you set a low value, TCP entries in
+		# Established states with no traffic may hang. For example,
+		# an SSH connection without KeepAlive enabled. If not set,
+		# the daemon uses an approximate timeout value calculation
+		# mechanism. By default, this option is not set.
+		#
+		# CommitTimeout 180
+
+		#
+		# If the firewall replica goes from primary to backup,
+		# the conntrackd -t command is invoked in the script. 
+		# This command schedules a flush of the table in N seconds.
+		# This is useful to purge the connection tracking table of
+		# zombie entries and avoid clashes with old entries if you
+		# trigger several consecutive hand-overs. Default is 60 seconds.
+		#
+		# PurgeTimeout 60
+
+		# Set the acknowledgement window size. If you decrease this
+		# value, the number of acknowlegdments increases. More
+		# acknowledgments means more overhead as conntrackd has to
+		# handle more control messages. On the other hand, if you
+		# increase this value, the resend queue gets more populated.
+		# This results in more overhead in the queue releasing.
+		# The following value is based on some practical experiments
+		# measuring the cycles spent by the acknowledgment handling
+		# with oprofile. If not set, default window size is 300.
+		#
+		# ACKWindowSize 300
+
+		#
+		# This clause allows you to disable the external cache. Thus,
+		# the state entries are directly injected into the kernel
+		# conntrack table. As a result, you save memory in user-space
+		# but you consume slots in the kernel conntrack table for
+		# backup state entries. Moreover, disabling the external cache
+		# means more CPU consumption. You need a Linux kernel
+		# >= 2.6.29 to use this feature. By default, this clause is
+		# set off. If you are installing conntrackd for first time,
+		# please read the user manual and I encourage you to consider
+		# using the fail-over scripts instead of enabling this option!
+		#
+		# DisableExternalCache Off
+	}
+
+	#
+	# Multicast IP and interface where messages are
+	# broadcasted (dedicated link). IMPORTANT: Make sure
+	# that iptables accepts traffic for destination
+	# 225.0.0.50, eg:
+	#
+	#	iptables -I INPUT -d 225.0.0.50 -j ACCEPT
+	#	iptables -I OUTPUT -d 225.0.0.50 -j ACCEPT
+	#
+	Multicast {
+		# 
+		# Multicast address: The address that you use as destination
+		# in the synchronization messages. You do not have to add
+		# this IP to any of your existing interfaces. If any doubt,
+		# do not modify this value.
+		#
+		IPv4_address 225.0.0.50
+
+		#
+		# The multicast group that identifies the cluster. If any
+		# doubt, do not modify this value.
+		#
+		Group 3780
+
+		#
+		# IP address of the interface that you are going to use to
+		# send the synchronization messages. Remember that you must
+		# use a dedicated link for the synchronization messages.
+		#
+		IPv4_interface 192.168.100.100
+
+		#
+		# The name of the interface that you are going to use to
+		# send the synchronization messages.
+		#
+		Interface eth2
+
+		# The multicast sender uses a buffer to enqueue the packets
+		# that are going to be transmitted. The default size of this
+		# socket buffer is available at /proc/sys/net/core/wmem_default.
+		# This value determines the chances to have an overrun in the
+		# sender queue. The overrun results packet loss, thus, losing
+		# state information that would have to be retransmitted. If you
+		# notice some packet loss, you may want to increase the size
+		# of the sender buffer. The default size is usually around
+		# ~100 KBytes which is fairly small for busy firewalls.
+		#
+		SndSocketBuffer 1249280
+
+		# The multicast receiver uses a buffer to enqueue the packets
+		# that the socket is pending to handle. The default size of this
+		# socket buffer is available at /proc/sys/net/core/rmem_default.
+		# This value determines the chances to have an overrun in the
+		# receiver queue. The overrun results packet loss, thus, losing
+		# state information that would have to be retransmitted. If you
+		# notice some packet loss, you may want to increase the size of
+		# the receiver buffer. The default size is usually around
+		# ~100 KBytes which is fairly small for busy firewalls.
+		#
+		RcvSocketBuffer 1249280
+
+		# 
+		# Enable/Disable message checksumming. This is a good
+		# property to achieve fault-tolerance. In case of doubt, do
+		# not modify this value.
+		#
+		Checksum on
+	}
+	#
+	# You can specify more than one dedicated link. Thus, if one dedicated
+	# link fails, conntrackd can fail-over to another. Note that adding
+	# more than one dedicated link does not mean that state-updates will
+	# be sent to all of them. There is only one active dedicated link at
+	# a given moment. The `Default' keyword indicates that this interface
+	# will be selected as the initial dedicated link. You can have 
+	# up to 4 redundant dedicated links. Note: Use different multicast 
+	# groups for every redundant link.
+	#
+	# Multicast Default {
+	#	IPv4_address 225.0.0.51
+	#	Group 3781
+	#	IPv4_interface 192.168.100.101
+	#	Interface eth3
+	#	# SndSocketBuffer 1249280
+	#	# RcvSocketBuffer 1249280
+	#	Checksum on
+	# }
+
+	#
+	# You can use Unicast UDP instead of Multicast to propagate events.
+	# Note that you cannot use unicast UDP and Multicast at the same
+	# time, you can only select one.
+	# 
+	# UDP {
+		# 
+		# UDP address that this firewall uses to listen to events.
+		#
+		# IPv4_address 192.168.2.100
+		#
+		# or you may want to use an IPv6 address:
+		#
+		# IPv6_address fe80::215:58ff:fe28:5a27
+
+		#
+		# Destination UDP address that receives events, ie. the other
+		# firewall's dedicated link address.
+		#
+		# IPv4_Destination_Address 192.168.2.101
+		#
+		# or you may want to use an IPv6 address:
+		#
+		# IPv6_Destination_Address fe80::2d0:59ff:fe2a:775c
+
+		#
+		# UDP port used
+		#
+		# Port 3780
+
+		#
+		# The name of the interface that you are going to use to
+		# send the synchronization messages.
+		#
+		# Interface eth2
+
+		# 
+		# The sender socket buffer size
+		#
+		# SndSocketBuffer 1249280
+
+		#
+		# The receiver socket buffer size
+		#
+		# RcvSocketBuffer 1249280
+
+		# 
+		# Enable/Disable message checksumming. 
+		#
+		# Checksum on
+	# }
+
+}
+
+#
+# General settings
+#
+General {
+	#
+	# Set the nice value of the daemon, this value goes from -20
+	# (most favorable scheduling) to 19 (least favorable). Using a
+	# very low value reduces the chances to lose state-change events.
+	# Default is 0 but this example file sets it to most favourable
+	# scheduling as this is generally a good idea. See man nice(1) for
+	# more information.
+	#
+	Nice -20
+
+	#
+	# Select a different scheduler for the daemon, you can select between
+	# RR and FIFO and the process priority (minimum is 0, maximum is 99).
+	# See man sched_setscheduler(2) for more information. Using a RT
+	# scheduler reduces the chances to overrun the Netlink buffer.
+	#
+	# Scheduler {
+	#	Type FIFO
+	#	Priority 99
+	# }
+
+	#
+	# Number of buckets in the cache hashtable. The bigger it is,
+	# the closer it gets to O(1) at the cost of consuming more memory.
+	# Read some documents about tuning hashtables for further reference.
+	#
+	HashSize 32768
+
+	#
+	# Maximum number of conntracks, it should be double of: 
+	# $ cat /proc/sys/net/netfilter/nf_conntrack_max
+	# since the daemon may keep some dead entries cached for possible
+	# retransmission during state synchronization.
+	#
+	HashLimit 131072
+
+	#
+	# Logfile: on (/var/log/conntrackd.log), off, or a filename
+	# Default: off
+	#
+	LogFile on
+
+	#
+	# Syslog: on, off or a facility name (daemon (default) or local0..7)
+	# Default: off
+	#
+	#Syslog on
+
+	#
+	# Lockfile
+	# 
+	LockFile /var/lock/conntrack.lock
+
+	#
+	# Unix socket configuration
+	#
+	UNIX {
+		Path /var/run/conntrackd.ctl
+		Backlog 20
+	}
+
+	#
+	# Netlink event socket buffer size. If you do not specify this clause,
+	# the default buffer size value in /proc/net/core/rmem_default is
+	# used. This default value is usually around 100 Kbytes which is
+	# fairly small for busy firewalls. This leads to event message dropping
+	# and high CPU consumption. This example configuration file sets the
+	# size to 2 MBytes to avoid this sort of problems.
+	#
+	NetlinkBufferSize 2097152
+
+	#
+	# The daemon doubles the size of the netlink event socket buffer size
+	# if it detects netlink event message dropping. This clause sets the
+	# maximum buffer size growth that can be reached. This example file
+	# sets the size to 8 MBytes.
+	#
+	NetlinkBufferSizeMaxGrowth 8388608
+
+	#
+	# If the daemon detects that Netlink is dropping state-change events,
+	# it automatically schedules a resynchronization against the Kernel
+	# after 30 seconds (default value). Resynchronizations are expensive
+	# in terms of CPU consumption since the daemon has to get the full
+	# kernel state-table and purge state-entries that do not exist anymore.
+	# Be careful of setting a very small value here. You have the following
+	# choices: On (enabled, use default 30 seconds value), Off (disabled)
+	# or Value (in seconds, to set a specific amount of time). If not
+	# specified, the daemon assumes that this option is enabled.
+	#
+	# NetlinkOverrunResync On
+
+	#
+	# If you want reliable event reporting over Netlink, set on this
+	# option. If you set on this clause, it is a good idea to set off
+	# NetlinkOverrunResync. This option is off by default and you need
+	# a Linux kernel >= 2.6.31.
+	#
+	# NetlinkEventsReliable Off
+
+	# 
+	# By default, the daemon receives state updates following an
+	# event-driven model. You can modify this behaviour by switching to
+	# polling mode with the PollSecs clause. This clause tells conntrackd
+	# to dump the states in the kernel every N seconds. With regards to
+	# synchronization mode, the polling mode can only guarantee that
+	# long-lifetime states are recovered. The main advantage of this method
+	# is the reduction in the state replication at the cost of reducing the
+	# chances of recovering connections.
+	#
+	# PollSecs 15
+
+	#
+	# The daemon prioritizes the handling of state-change events coming
+	# from the core. With this clause, you can set the maximum number of
+	# state-change events (those coming from kernel-space) that the daemon
+	# will handle after which it will handle other events coming from the
+	# network or userspace. A low value improves interactivity (in terms of
+	# real-time behaviour) at the cost of extra CPU consumption.
+	# Default (if not set) is 100.
+	#
+	# EventIterationLimit 100
+
+	#
+	# Event filtering: This clause allows you to filter certain traffic,
+	# There are currently three filter-sets: Protocol, Address and
+	# State. The filter is attached to an action that can be: Accept or
+	# Ignore. Thus, you can define the event filtering policy of the
+	# filter-sets in positive or negative logic depending on your needs.
+	# You can select if conntrackd filters the event messages from 
+	# user-space or kernel-space. The kernel-space event filtering
+	# saves some CPU cycles by avoiding the copy of the event message
+	# from kernel-space to user-space. The kernel-space event filtering
+	# is prefered, however, you require a Linux kernel >= 2.6.29 to
+	# filter from kernel-space. If you want to select kernel-space 
+	# event filtering, use the keyword 'Kernelspace' instead of 
+	# 'Userspace'.
+	#
+	Filter From Userspace {
+		#
+		# Accept only certain protocols: You may want to replicate
+		# the state of flows depending on their layer 4 protocol.
+		#
+		Protocol Accept {
+			TCP
+			SCTP
+			DCCP
+			# ICMP # This requires a Linux kernel >= 2.6.31
+		}
+
+		#
+		# Ignore traffic for a certain set of IP's: Usually all the
+		# IP assigned to the firewall since local traffic must be
+		# ignored, only forwarded connections are worth to replicate.
+		# Note that these values depends on the local IPs that are
+		# assigned to the firewall.
+		#
+		Address Ignore {
+			IPv4_address 127.0.0.1 # loopback
+			IPv4_address 192.168.0.100 # virtual IP 1
+			IPv4_address 192.168.1.100 # virtual IP 2
+			IPv4_address 192.168.0.1
+			IPv4_address 192.168.1.1
+			IPv4_address 192.168.100.100 # dedicated link ip
+			#
+			# You can also specify networks in format IP/cidr.
+			# IPv4_address 192.168.0.0/24
+			#
+			# You can also specify an IPv6 address
+			# IPv6_address ::1
+		}
+
+		#
+		# Uncomment this line below if you want to filter by flow state.
+		# This option introduces a trade-off in the replication: it
+		# reduces CPU consumption at the cost of having lazy backup 
+		# firewall replicas. The existing TCP states are: SYN_SENT,
+		# SYN_RECV, ESTABLISHED, FIN_WAIT, CLOSE_WAIT, LAST_ACK,
+		# TIME_WAIT, CLOSED, LISTEN.
+		#
+		# State Accept {
+		#	ESTABLISHED CLOSED TIME_WAIT CLOSE_WAIT for TCP
+		# }
+	}
+}
diff --git a/doc/sync/ftfw/conntrackd.conf.orig b/doc/sync/ftfw/conntrackd.conf.orig
new file mode 100644
index 0000000..c1208f9
--- /dev/null
+++ b/doc/sync/ftfw/conntrackd.conf.orig
@@ -0,0 +1,370 @@
+#
+# Synchronizer settings
+#
+Sync {
+	Mode FTFW {
+		#
+		# Size of the resend queue (in objects). This is the maximum
+		# number of objects that can be stored waiting to be confirmed
+		# via acknoledgment. If you keep this value low, the daemon
+		# will have less chances to recover state-changes under message
+		# omission. On the other hand, if you keep this value high,
+		# the daemon will consume more memory to store dead objects.
+		# Default is 131072 objects.
+		#
+		# ResendQueueSize 131072
+
+		#
+		# This parameter allows you to set an initial fixed timeout
+		# for the committed entries when this node goes from backup
+		# to primary. This mechanism provides a way to purge entries
+		# that were not recovered appropriately after the specified
+		# fixed timeout. If you set a low value, TCP entries in
+		# Established states with no traffic may hang. For example,
+		# an SSH connection without KeepAlive enabled. If not set,
+		# the daemon uses an approximate timeout value calculation
+		# mechanism. By default, this option is not set.
+		#
+		# CommitTimeout 180
+
+		#
+		# If the firewall replica goes from primary to backup,
+		# the conntrackd -t command is invoked in the script. 
+		# This command schedules a flush of the table in N seconds.
+		# This is useful to purge the connection tracking table of
+		# zombie entries and avoid clashes with old entries if you
+		# trigger several consecutive hand-overs. Default is 60 seconds.
+		#
+		# PurgeTimeout 60
+
+		# Set the acknowledgement window size. If you decrease this
+		# value, the number of acknowlegdments increases. More
+		# acknowledgments means more overhead as conntrackd has to
+		# handle more control messages. On the other hand, if you
+		# increase this value, the resend queue gets more populated.
+		# This results in more overhead in the queue releasing.
+		# The following value is based on some practical experiments
+		# measuring the cycles spent by the acknowledgment handling
+		# with oprofile. If not set, default window size is 300.
+		#
+		# ACKWindowSize 300
+	}
+
+	#
+	# Multicast IP and interface where messages are
+	# broadcasted (dedicated link). IMPORTANT: Make sure
+	# that iptables accepts traffic for destination
+	# 225.0.0.50, eg:
+	#
+	#	iptables -I INPUT -d 225.0.0.50 -j ACCEPT
+	#	iptables -I OUTPUT -d 225.0.0.50 -j ACCEPT
+	#
+	Multicast {
+		# 
+		# Multicast address: The address that you use as destination
+		# in the synchronization messages. You do not have to add
+		# this IP to any of your existing interfaces. If any doubt,
+		# do not modify this value.
+		#
+		IPv4_address 225.0.0.50
+
+		#
+		# The multicast group that identifies the cluster. If any
+		# doubt, do not modify this value.
+		#
+		Group 3780
+
+		#
+		# IP address of the interface that you are going to use to
+		# send the synchronization messages. Remember that you must
+		# use a dedicated link for the synchronization messages.
+		#
+		IPv4_interface 192.168.100.100
+
+		#
+		# The name of the interface that you are going to use to
+		# send the synchronization messages.
+		#
+		Interface eth2
+
+		# The multicast sender uses a buffer to enqueue the packets
+		# that are going to be transmitted. The default size of this
+		# socket buffer is available at /proc/sys/net/core/wmem_default.
+		# This value determines the chances to have an overrun in the
+		# sender queue. The overrun results packet loss, thus, losing
+		# state information that would have to be retransmitted. If you
+		# notice some packet loss, you may want to increase the size
+		# of the sender buffer. The default size is usually around
+		# ~100 KBytes which is fairly small for busy firewalls.
+		#
+		SndSocketBuffer 1249280
+
+		# The multicast receiver uses a buffer to enqueue the packets
+		# that the socket is pending to handle. The default size of this
+		# socket buffer is available at /proc/sys/net/core/rmem_default.
+		# This value determines the chances to have an overrun in the
+		# receiver queue. The overrun results packet loss, thus, losing
+		# state information that would have to be retransmitted. If you
+		# notice some packet loss, you may want to increase the size of
+		# the receiver buffer. The default size is usually around
+		# ~100 KBytes which is fairly small for busy firewalls.
+		#
+		RcvSocketBuffer 1249280
+
+		# 
+		# Enable/Disable message checksumming. This is a good
+		# property to achieve fault-tolerance. In case of doubt, do
+		# not modify this value.
+		#
+		Checksum on
+	}
+	#
+	# You can specify more than one dedicated link. Thus, if one dedicated
+	# link fails, conntrackd can fail-over to another. Note that adding
+	# more than one dedicated link does not mean that state-updates will
+	# be sent to all of them. There is only one active dedicated link at
+	# a given moment. The `Default' keyword indicates that this interface
+	# will be selected as the initial dedicated link. You can have 
+	# up to 4 redundant dedicated links. Note: Use different multicast 
+	# groups for every redundant link.
+	#
+	# Multicast Default {
+	#	IPv4_address 225.0.0.51
+	#	Group 3781
+	#	IPv4_interface 192.168.100.101
+	#	Interface eth3
+	#	# SndSocketBuffer 1249280
+	#	# RcvSocketBuffer 1249280
+	#	Checksum on
+	# }
+
+	#
+	# You can use Unicast UDP instead of Multicast to propagate events.
+	# Note that you cannot use unicast UDP and Multicast at the same
+	# time, you can only select one.
+	# 
+	# UDP {
+		# 
+		# UDP address that this firewall uses to listen to events.
+		#
+		# IPv4_address 192.168.2.100
+		#
+		# or you may want to use an IPv6 address:
+		#
+		# IPv6_address fe80::215:58ff:fe28:5a27
+
+		#
+		# Destination UDP address that receives events, ie. the other
+		# firewall's dedicated link address.
+		#
+		# IPv4_Destination_Address 192.168.2.101
+		#
+		# or you may want to use an IPv6 address:
+		#
+		# IPv6_Destination_Address fe80::2d0:59ff:fe2a:775c
+
+		#
+		# UDP port used
+		#
+		# Port 3780
+
+		#
+		# The name of the interface that you are going to use to
+		# send the synchronization messages.
+		#
+		# Interface eth2
+
+		# 
+		# The sender socket buffer size
+		#
+		# SndSocketBuffer 1249280
+
+		#
+		# The receiver socket buffer size
+		#
+		# RcvSocketBuffer 1249280
+
+		# 
+		# Enable/Disable message checksumming. 
+		#
+		# Checksum on
+	# }
+}
+
+#
+# General settings
+#
+General {
+	#
+	# Set the nice value of the daemon, this value goes from -20
+	# (most favorable scheduling) to 19 (least favorable). Using a
+	# very low value reduces the chances to lose state-change events.
+	# Default is 0 but this example file sets it to most favourable
+	# scheduling as this is generally a good idea. See man nice(1) for
+	# more information.
+	#
+	Nice -20
+
+	#
+	# Select a different scheduler for the daemon, you can select between
+	# RR and FIFO and the process priority (minimum is 0, maximum is 99).
+	# See man sched_setscheduler(2) for more information. Using a RT
+	# scheduler reduces the chances to overrun the Netlink buffer.
+	#
+	# Scheduler {
+	#	Type FIFO
+	#	Priority 99
+	# }
+
+	#
+	# Number of buckets in the cache hashtable. The bigger it is,
+	# the closer it gets to O(1) at the cost of consuming more memory.
+	# Read some documents about tuning hashtables for further reference.
+	#
+	HashSize 32768
+
+	#
+	# Maximum number of conntracks, it should be double of: 
+	# $ cat /proc/sys/net/netfilter/nf_conntrack_max
+	# since the daemon may keep some dead entries cached for possible
+	# retransmission during state synchronization.
+	#
+	HashLimit 131072
+
+	#
+	# Logfile: on (/var/log/conntrackd.log), off, or a filename
+	# Default: off
+	#
+	LogFile on
+
+	#
+	# Syslog: on, off or a facility name (daemon (default) or local0..7)
+	# Default: off
+	#
+	#Syslog on
+
+	#
+	# Lockfile
+	# 
+	LockFile /var/lock/conntrack.lock
+
+	#
+	# Unix socket configuration
+	#
+	UNIX {
+		Path /var/run/conntrackd.ctl
+		Backlog 20
+	}
+
+	#
+	# Netlink event socket buffer size. If you do not specify this clause,
+	# the default buffer size value in /proc/net/core/rmem_default is
+	# used. This default value is usually around 100 Kbytes which is
+	# fairly small for busy firewalls. This leads to event message dropping
+	# and high CPU consumption. This example configuration file sets the
+	# size to 2 MBytes to avoid this sort of problems.
+	#
+	NetlinkBufferSize 2097152
+
+	#
+	# The daemon doubles the size of the netlink event socket buffer size
+	# if it detects netlink event message dropping. This clause sets the
+	# maximum buffer size growth that can be reached. This example file
+	# sets the size to 8 MBytes.
+	#
+	NetlinkBufferSizeMaxGrowth 8388608
+
+	#
+	# If the daemon detects that Netlink is dropping state-change events,
+	# it automatically schedules a resynchronization against the Kernel
+	# after 30 seconds (default value). Resynchronizations are expensive
+	# in terms of CPU consumption since the daemon has to get the full
+	# kernel state-table and purge state-entries that do not exist anymore.
+	# Be careful of setting a very small value here. You have the following
+	# choices: On (enabled, use default 30 seconds value), Off (disabled)
+	# or Value (in seconds, to set a specific amount of time). If not
+	# specified, the daemon assumes that this option is enabled.
+	#
+	# NetlinkOverrunResync On
+
+	# 
+	# By default, the daemon receives state updates following an
+	# event-driven model. You can modify this behaviour by switching to
+	# polling mode with the PollSecs clause. This clause tells conntrackd
+	# to dump the states in the kernel every N seconds. With regards to
+	# synchronization mode, the polling mode can only guarantee that
+	# long-lifetime states are recovered. The main advantage of this method
+	# is the reduction in the state replication at the cost of reducing the
+	# chances of recovering connections.
+	#
+	# PollSecs 15
+
+	#
+	# The daemon prioritizes the handling of state-change events coming
+	# from the core. With this clause, you can set the maximum number of
+	# state-change events (those coming from kernel-space) that the daemon
+	# will handle after which it will handle other events coming from the
+	# network or userspace. A low value improves interactivity (in terms of
+	# real-time behaviour) at the cost of extra CPU consumption.
+	# Default (if not set) is 100.
+	#
+	# EventIterationLimit 100
+
+	#
+	# Event filtering: This clause allows you to filter certain traffic,
+	# There are currently three filter-sets: Protocol, Address and
+	# State. The filter is attached to an action that can be: Accept or
+	# Ignore. Thus, you can define the event filtering policy of the
+	# filter-sets in positive or negative logic depending on your needs.
+	# You can select if conntrackd filters the event messages from 
+	# user-space or kernel-space. The kernel-space event filtering
+	# saves some CPU cycles by avoiding the copy of the event message
+	# from kernel-space to user-space. The kernel-space event filtering
+	# is prefered, however, you require a Linux kernel >= 2.6.29 to
+	# filter from kernel-space. If you want to select kernel-space 
+	# event filtering, use the keyword 'Kernelspace' instead of 
+	# 'Userspace'.
+	#
+	Filter From Userspace {
+		#
+		# Accept only certain protocols: You may want to replicate
+		# the state of flows depending on their layer 4 protocol.
+		#
+		Protocol Accept {
+			TCP
+			SCTP
+			DCCP
+		}
+
+		#
+		# Ignore traffic for a certain set of IP's: Usually all the
+		# IP assigned to the firewall since local traffic must be
+		# ignored, only forwarded connections are worth to replicate.
+		# Note that these values depends on the local IPs that are
+		# assigned to the firewall.
+		#
+		Address Ignore {
+			IPv4_address 127.0.0.1 # loopback
+			IPv4_address 192.168.0.100 # virtual IP 1
+			IPv4_address 192.168.1.100 # virtual IP 2
+			IPv4_address 192.168.0.1
+			IPv4_address 192.168.1.1
+			IPv4_address 192.168.100.100 # dedicated link ip
+			#
+			# You can also specify networks in format IP/cidr.
+			# IPv4_address 192.168.0.0/24
+		}
+
+		#
+		# Uncomment this line below if you want to filter by flow state.
+		# This option introduces a trade-off in the replication: it
+		# reduces CPU consumption at the cost of having lazy backup 
+		# firewall replicas. The existing TCP states are: SYN_SENT,
+		# SYN_RECV, ESTABLISHED, FIN_WAIT, CLOSE_WAIT, LAST_ACK,
+		# TIME_WAIT, CLOSED, LISTEN.
+		#
+		# State Accept {
+		#	ESTABLISHED CLOSED TIME_WAIT CLOSE_WAIT for TCP
+		# }
+	}
+}
diff --git a/doc/sync/keepalived-multi1.conf b/doc/sync/keepalived-multi1.conf
new file mode 100644
index 0000000..5ffb318
--- /dev/null
+++ b/doc/sync/keepalived-multi1.conf
@@ -0,0 +1,71 @@
+#
+# Simple script for multi-primary setups
+#
+
+vrrp_sync_group G1 {   # must be before vrrp_instance declaration
+  group {
+    VI_1
+    VI_2
+  }
+  notify_master "/etc/conntrackd/multiprimary.sh primary 1"
+  notify_backup "/etc/conntrackd/multiprimary.sh backup 1"
+  notify_fault "/etc/conntrackd/multiprimary.sh fault 1"
+}
+
+vrrp_sync_group G2 {   # must be before vrrp_instance declaration
+  group {
+    VI_3
+    VI_4
+  }
+  notify_master "/etc/conntrackd/multiprimary.sh primary 2"
+  notify_backup "/etc/conntrackd/multiprimary.sh backup 2"
+  notify_fault "/etc/conntrackd/multiprimary.sh fault 2"
+}
+
+vrrp_instance VI_1 {
+    interface eth1
+    state SLAVE
+    virtual_router_id 61
+    priority 90
+    advert_int 3
+    authentication {
+      auth_type PASS
+      auth_pass papas_con_tomate
+    }
+}
+
+vrrp_instance VI_2 {
+    interface eth2
+    state SLAVE
+    virtual_router_id 61
+    priority 90
+    advert_int 3
+    authentication {
+      auth_type PASS
+      auth_pass papas_con_tomate
+    }
+}
+
+vrrp_instance VI_3 {
+    interface eth1
+    state SLAVE
+    virtual_router_id 62
+    priority 10
+    advert_int 3
+    authentication {
+      auth_type PASS
+      auth_pass papas_con_tomate
+    }
+}
+
+vrrp_instance VI_4 {
+    interface eth2
+    state SLAVE
+    virtual_router_id 62
+    priority 10
+    advert_int 3
+    authentication {
+      auth_type PASS
+      auth_pass papas_con_tomate
+    }
+}
diff --git a/doc/sync/keepalived-multi2.conf b/doc/sync/keepalived-multi2.conf
new file mode 100644
index 0000000..91ab019
--- /dev/null
+++ b/doc/sync/keepalived-multi2.conf
@@ -0,0 +1,71 @@
+#
+# Simple script for multi-primary setups
+#
+
+vrrp_sync_group G1 {   # must be before vrrp_instance declaration
+  group {
+    VI_1
+    VI_2
+  }
+  notify_master "/etc/conntrackd/multiprimary.sh primary 1"
+  notify_backup "/etc/conntrackd/multiprimary.sh backup 1"
+  notify_fault "/etc/conntrackd/multiprimary.sh fault 1"
+}
+
+vrrp_sync_group G2 {   # must be before vrrp_instance declaration
+  group {
+    VI_3
+    VI_4
+  }
+  notify_master "/etc/conntrackd/multiprimary.sh primary 2"
+  notify_backup "/etc/conntrackd/multiprimary.sh backup 2"
+  notify_fault "/etc/conntrackd/multiprimary.sh fault 2"
+}
+
+vrrp_instance VI_1 {
+    interface eth1
+    state SLAVE
+    virtual_router_id 61
+    priority 10
+    advert_int 3
+    authentication {
+      auth_type PASS
+      auth_pass papas_con_tomate
+    }
+}
+
+vrrp_instance VI_2 {
+    interface eth2
+    state SLAVE
+    virtual_router_id 61
+    priority 10
+    advert_int 3
+    authentication {
+      auth_type PASS
+      auth_pass papas_con_tomate
+    }
+}
+
+vrrp_instance VI_3 {
+    interface eth1
+    state SLAVE 
+    virtual_router_id 62
+    priority 90
+    advert_int 3
+    authentication {
+      auth_type PASS
+      auth_pass papas_con_tomate
+    }
+}
+
+vrrp_instance VI_4 {
+    interface eth2
+    state SLAVE
+    virtual_router_id 62
+    priority 90
+    advert_int 3
+    authentication {
+      auth_type PASS
+      auth_pass papas_con_tomate
+    }
+}
diff --git a/doc/sync/keepalived.conf b/doc/sync/keepalived.conf
new file mode 100644
index 0000000..84f1383
--- /dev/null
+++ b/doc/sync/keepalived.conf
@@ -0,0 +1,43 @@
+#
+# Simple script for primary-backup setups
+#
+
+vrrp_sync_group G1 {   # must be before vrrp_instance declaration
+  group {
+    VI_1
+    VI_2
+  }
+  notify_master "/etc/conntrackd/primary-backup.sh primary"
+  notify_backup "/etc/conntrackd/primary-backup.sh backup"
+  notify_fault "/etc/conntrackd/primary-backup.sh fault"
+}
+
+vrrp_instance VI_1 {
+    interface eth1
+    state SLAVE
+    virtual_router_id 61
+    priority 80
+    advert_int 3
+    authentication {
+      auth_type PASS
+      auth_pass papas_con_tomate
+    }
+    virtual_ipaddress {
+        192.168.0.100   # default CIDR mask is /32
+    }
+}
+
+vrrp_instance VI_2 {
+    interface eth0
+    state SLAVE
+    virtual_router_id 62
+    priority 80
+    advert_int 3
+    authentication {
+      auth_type PASS
+      auth_pass papas_con_tomate
+    }
+    virtual_ipaddress {
+        192.168.1.100
+    }
+}
diff --git a/doc/sync/multiprimary.sh b/doc/sync/multiprimary.sh
new file mode 100755
index 0000000..5c585c9
--- /dev/null
+++ b/doc/sync/multiprimary.sh
@@ -0,0 +1,212 @@
+#!/bin/sh
+# 
+# (C) 2009 by Pablo Neira Ayuso <pablo@netfilter.org>
+#
+# This software may be used and distributed according to the terms
+# of the GNU General Public License, incorporated herein by reference.
+#
+
+#
+# This is the node ID, must be >= 1 and <= 2. You have to CHANGE IT according
+# to the number of node where you are.
+#
+NODEID=1
+
+CONNTRACKD_BIN="/usr/sbin/conntrackd"
+CONNTRACKD_LOCK="/var/lock/conntrack.lock"
+CONNTRACKD_CONFIG="/etc/conntrackd/conntrackd.conf"
+
+ETHER1="eth1"
+ETHER2="eth2"
+
+state_primary()
+{
+    #
+    # commit the external cache into the kernel table
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -c
+    if [ $? -eq 1 ]
+    then
+        logger "ERROR: failed to invoke conntrackd -c"
+    fi
+
+    #
+    # flush the internal and the external caches
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -f
+    if [ $? -eq 1 ]
+    then
+    	logger "ERROR: failed to invoke conntrackd -f"
+    fi
+
+    #
+    # resynchronize my internal cache to the kernel table
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -R
+    if [ $? -eq 1 ]
+    then
+    	logger "ERROR: failed to invoke conntrackd -R"
+    fi
+
+    #
+    # send a bulk update to backups 
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -B
+    if [ $? -eq 1 ]
+    then
+        logger "ERROR: failed to invoke conntrackd -B"
+    fi
+}
+
+state_backup() {
+    #
+    # is conntrackd running? request some statistics to check it
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -s
+    if [ $? -eq 1 ]
+    then
+        #
+	# something's wrong, do we have a lock file?
+	#
+    	if [ -f $CONNTRACKD_LOCK ]
+	then
+	    logger "WARNING: conntrackd was not cleanly stopped."
+	    logger "If you suspect that it has crashed:"
+	    logger "1) Enable coredumps"
+	    logger "2) Try to reproduce the problem"
+	    logger "3) Post the coredump to netfilter-devel@vger.kernel.org"
+	    rm -f $CONNTRACKD_LOCK
+	fi
+	$CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -d
+	if [ $? -eq 1 ]
+	then
+	    logger "ERROR: cannot launch conntrackd"
+	    exit 1
+	fi
+    fi
+    #
+    # shorten kernel conntrack timers to remove the zombie entries.
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -t
+    if [ $? -eq 1 ]
+    then
+    	logger "ERROR: failed to invoke conntrackd -t"
+    fi
+
+    #
+    # request resynchronization with master firewall replica (if any)
+    # Note: this does nothing in the alarm approach.
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -n
+    if [ $? -eq 1 ]
+    then
+    	logger "ERROR: failed to invoke conntrackd -n"
+    fi
+}
+
+state_fault() {
+    #
+    # shorten kernel conntrack timers to remove the zombie entries.
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -t
+    if [ $? -eq 1 ]
+    then
+    	logger "ERROR: failed to invoke conntrackd -t"
+    fi
+}
+
+iptables_add_cluster_rule() {
+    iptables -I CLUSTERDEV1 -t mangle -m cluster \
+    --cluster-total-nodes 2 --cluster-local-node $1 \
+    --cluster-hash-seed 0xdeadbeed -j MARK --set-mark 0xffff
+    iptables -I CLUSTERDEV2 -t mangle -m cluster \
+    --cluster-total-nodes 2 --cluster-local-node $1 \
+    --cluster-hash-seed 0xdeadbeed -j MARK --set-mark 0xffff
+}
+
+iptables_del_cluster_rule() {
+    iptables -D CLUSTERDEV1 -t mangle -m cluster \
+    --cluster-total-nodes 2 --cluster-local-node $1 \
+    --cluster-hash-seed 0xdeadbeed -j MARK --set-mark 0xffff
+    iptables -D CLUSTERDEV2 -t mangle -m cluster \
+    --cluster-total-nodes 2 --cluster-local-node $1 \
+    --cluster-hash-seed 0xdeadbeed -j MARK --set-mark 0xffff
+}
+
+iptables_start_cluster_rule() {
+    iptables -N CLUSTERDEV1 -t mangle
+    iptables -N CLUSTERDEV2 -t mangle
+    iptables_add_cluster_rule $1
+    iptables -A CLUSTERDEV1 -t mangle -m mark ! --mark 0xffff -j DROP
+    iptables -A CLUSTERDEV2 -t mangle -m mark ! --mark 0xffff -j DROP
+    iptables -I PREROUTING -t mangle -p vrrp -j ACCEPT
+    iptables -A PREROUTING -t mangle -i $ETHER1 -j CLUSTERDEV1
+    iptables -A PREROUTING -t mangle -i $ETHER2 -j CLUSTERDEV2
+}
+
+iptables_stop_cluster_rule() {
+    iptables -D PREROUTING -t mangle -i $ETHER1 -j CLUSTERDEV1
+    iptables -D PREROUTING -t mangle -i $ETHER2 -j CLUSTERDEV2
+    iptables -D PREROUTING -t mangle -p vrrp -j ACCEPT 
+    iptables -F CLUSTERDEV1 -t mangle
+    iptables -F CLUSTERDEV2 -t mangle
+    iptables -X CLUSTERDEV1 -t mangle
+    iptables -X CLUSTERDEV2 -t mangle
+}
+
+# this can be called without options
+case "$1" in
+  start)
+    iptables_start_cluster_rule $NODEID
+    exit 0
+    ;;
+  stop)
+    iptables_stop_cluster_rule $NODEID
+    exit 0
+    ;;
+esac
+
+if [ $# -ne 2 ]
+then
+    logger "ERROR: missing arguments"
+    echo "Usage: $0 {primary|backup|fault|start|stop} {nodeid}"
+    exit 1
+fi
+
+case "$1" in
+  primary)
+    #
+    # We are entering the MASTER state, it may be for G1 or G2, but we
+    # commit the external cache anyway.
+    #
+    state_primary
+    iptables_add_cluster_rule $2
+    ;;
+  backup)
+    #
+    # We are entering the BACKUP state. We can enter it from G1 or G2.
+    # Assuming that we are node 1 and that we have entered BACKUP in G2,
+    # this means that node 2 has come back to life. In that case, skip
+    # state_backup because we are still in MASTER state for G1.
+    #
+    if [ $NODEID -eq $2 ]
+    then
+       state_backup
+    fi
+    iptables_del_cluster_rule $2
+    ;;
+  fault)
+    #
+    # We are entering the FAULT state, something bad is happening to us.
+    #
+    state_fault
+    iptables_del_cluster_rule $2
+    ;;
+  *)
+    logger "ERROR: unknown state transition"
+    echo "Usage: $0 {primary|backup|fault|start|stop} {nodeid}"
+    exit 1
+    ;;
+esac
+
+exit 0
diff --git a/doc/sync/notrack/README b/doc/sync/notrack/README
new file mode 100644
index 0000000..b064e21
--- /dev/null
+++ b/doc/sync/notrack/README
@@ -0,0 +1,3 @@
+This directory contains the files for the NOTRACK replication protocol. This
+protocol provides best effort delivery. Therefore, it is unreliable unless
+that you select TCP-based state-synchronization.
diff --git a/doc/sync/notrack/conntrackd.conf b/doc/sync/notrack/conntrackd.conf
new file mode 100644
index 0000000..f8bccc4
--- /dev/null
+++ b/doc/sync/notrack/conntrackd.conf
@@ -0,0 +1,434 @@
+#
+# Synchronizer settings
+#
+Sync {
+	Mode NOTRACK {
+		#
+		# This parameter allows you to set an initial fixed timeout
+		# for the committed entries when this node goes from backup
+		# to primary. This mechanism provides a way to purge entries
+		# that were not recovered appropriately after the specified
+		# fixed timeout. If you set a low value, TCP entries in
+		# Established states with no traffic may hang. For example,
+		# an SSH connection without KeepAlive enabled. If not set,
+		# the daemon uses an approximate timeout value calculation
+		# mechanism. By default, this option is not set.
+		#
+		# CommitTimeout 180
+
+		#
+		# If the firewall replica goes from primary to backup,
+		# the conntrackd -t command is invoked in the script. 
+		# This command schedules a flush of the table in N seconds.
+		# This is useful to purge the connection tracking table of
+		# zombie entries and avoid clashes with old entries if you
+		# trigger several consecutive hand-overs. Default is 60 seconds.
+		#
+		# PurgeTimeout 60
+
+		#
+		# This clause allows you to disable the internal cache. Thus,
+		# the synchronization messages are directly send through
+		# the dedicated link. This option is set of off by default.
+		#
+		# DisableInternalCache Off
+
+		#	
+		# This clause allows you to disable the external cache. Thus,
+		# the state entries are directly injected into the kernel
+		# conntrack table. As a result, you save memory in user-space
+		# but you consume slots in the kernel conntrack table for
+		# backup state entries. Moreover, disabling the external cache
+		# means more CPU consumption. You need a Linux kernel
+		# >= 2.6.29 to use this feature. By default, this clause is
+		# set off. If you are installing conntrackd for first time,
+		# please read the user manual and I encourage you to consider
+		# using the fail-over scripts instead of enabling this option!
+		#
+		# DisableExternalCache Off
+	}
+
+	#
+	# Multicast IP and interface where messages are
+	# broadcasted (dedicated link). IMPORTANT: Make sure
+	# that iptables accepts traffic for destination
+	# 225.0.0.50, eg:
+	#
+	#	iptables -I INPUT -d 225.0.0.50 -j ACCEPT
+	#	iptables -I OUTPUT -d 225.0.0.50 -j ACCEPT
+	#
+	Multicast {
+		# 
+		# Multicast address: The address that you use as destination
+		# in the synchronization messages. You do not have to add
+		# this IP to any of your existing interfaces. If any doubt,
+		# do not modify this value.
+		#
+		IPv4_address 225.0.0.50
+
+		#
+		# The multicast group that identifies the cluster. If any
+		# doubt, do not modify this value.
+		#
+		Group 3780
+
+		#
+		# IP address of the interface that you are going to use to
+		# send the synchronization messages. Remember that you must
+		# use a dedicated link for the synchronization messages.
+		#
+		IPv4_interface 192.168.100.100
+
+		#
+		# The name of the interface that you are going to use to
+		# send the synchronization messages.
+		#
+		Interface eth2
+
+		# The multicast sender uses a buffer to enqueue the packets
+		# that are going to be transmitted. The default size of this
+		# socket buffer is available at /proc/sys/net/core/wmem_default.
+		# This value determines the chances to have an overrun in the
+		# sender queue. The overrun results packet loss, thus, losing
+		# state information that would have to be retransmitted. If you
+		# notice some packet loss, you may want to increase the size
+		# of the sender buffer. The default size is usually around
+		# ~100 KBytes which is fairly small for busy firewalls.
+		# Note: This protocol is best effort, it is really recommended
+		# to increase the buffer size.
+		#
+		SndSocketBuffer 1249280
+
+		# The multicast receiver uses a buffer to enqueue the packets
+		# that the socket is pending to handle. The default size of this
+		# socket buffer is available at /proc/sys/net/core/rmem_default.
+		# This value determines the chances to have an overrun in the
+		# receiver queue. The overrun results packet loss, thus, losing
+		# state information that would have to be retransmitted. If you
+		# notice some packet loss, you may want to increase the size of
+		# of the sender buffer. The default size is usually around
+		# ~100 KBytes which is fairly small for busy firewalls.
+		# Note: This protocol is best effort, it is really recommended
+		# to increase the buffer size.
+		#
+		RcvSocketBuffer 1249280
+
+		#
+		# Enable/Disable message checksumming. This is a good
+		# property to achieve fault-tolerance. In case of doubt, do
+		# not modify this value.
+		#
+		Checksum on
+	}
+	#
+	# You can specify more than one dedicated link. Thus, if one dedicated
+	# link fails, conntrackd can fail-over to another. Note that adding
+	# more than one dedicated link does not mean that state-updates will
+	# be sent to all of them. There is only one active dedicated link at
+	# a given moment. The `Default' keyword indicates that this interface
+	# will be selected as the initial dedicated link. You can have 
+	# up to 4 redundant dedicated links. Note: Use different multicast 
+	# groups for every redundant link.
+	#
+	# Multicast Default {
+	#	IPv4_address 225.0.0.51
+	#	Group 3781
+	#	IPv4_interface 192.168.100.101
+	#	Interface eth3
+	#	# SndSocketBuffer 1249280
+	#	# RcvSocketBuffer 1249280
+	#	Checksum on
+	# }
+
+	#
+	# You can use Unicast UDP instead of Multicast to propagate events.
+	# Note that you cannot use unicast UDP and Multicast at the same
+	# time, you can only select one.
+	# 
+	# UDP {
+		# 
+		# UDP address that this firewall uses to listen to events.
+		#
+		# IPv4_address 192.168.2.100
+		#
+		# or you may want to use an IPv6 address:
+		#
+		# IPv6_address fe80::215:58ff:fe28:5a27
+
+		#
+		# Destination UDP address that receives events, ie. the other
+		# firewall's dedicated link address.
+		#
+		# IPv4_Destination_Address 192.168.2.101
+		#
+		# or you may want to use an IPv6 address:
+		#
+		# IPv6_Destination_Address fe80::2d0:59ff:fe2a:775c
+
+		#
+		# UDP port used
+		#
+		# Port 3780
+
+		#
+		# The name of the interface that you are going to use to
+		# send the synchronization messages.
+		#
+		# Interface eth2
+
+		# 
+		# The sender socket buffer size
+		#
+		# SndSocketBuffer 1249280
+
+		#
+		# The receiver socket buffer size
+		#
+		# RcvSocketBuffer 1249280
+
+		# 
+		# Enable/Disable message checksumming. 
+		#
+		# Checksum on
+	# }
+
+	#
+	# You can also use Unicast TCP to propagate events. Thus, the NOTRACK
+	# mode becomes reliable.
+	# 
+	# TCP {
+		# 
+		# TCP address that this firewall uses to listen to events.
+		#
+		# IPv4_address 192.168.2.100
+		#
+		# or you may want to use an IPv6 address:
+		#
+		# IPv6_address fe80::215:58ff:fe28:5a27
+
+		#
+		# Destination TCP address that receives events, ie. the other
+		# firewall's dedicated link address.
+		#
+		# IPv4_Destination_Address 192.168.2.101
+		#
+		# or you may want to use an IPv6 address:
+		#
+		# IPv6_Destination_Address fe80::2d0:59ff:fe2a:775c
+
+		#
+		# TCP port used
+		#
+		# Port 3780
+
+		#
+		# The name of the interface that you are going to use to
+		# send the synchronization messages.
+		#
+		# Interface eth2
+
+		# 
+		# The sender socket buffer size
+		#
+		# SndSocketBuffer 1249280
+
+		#
+		# The receiver socket buffer size
+		#
+		# RcvSocketBuffer 1249280
+
+		# 
+		# Enable/Disable message checksumming. 
+		#
+		# Checksum on
+	# }
+}
+
+#
+# General settings
+#
+General {
+	#
+	# Set the nice value of the daemon, this value goes from -20
+	# (most favorable scheduling) to 19 (least favorable). Using a
+	# very low value reduces the chances to lose state-change events.
+	# Default is 0 but this example file sets it to most favourable
+	# scheduling as this is generally a good idea. See man nice(1) for
+	# more information.
+	#
+	Nice -20
+
+	#
+	# Select a different scheduler for the daemon, you can select between
+	# RR and FIFO and the process priority (minimum is 0, maximum is 99).
+	# See man sched_setscheduler(2) for more information. Using a RT
+	# scheduler reduces the chances to overrun the Netlink buffer.
+	#
+	# Scheduler {
+	#	Type FIFO
+	#	Priority 99
+	# }
+
+	#
+	# Number of buckets in the cache hashtable. The bigger it is,
+	# the closer it gets to O(1) at the cost of consuming more memory.
+	# Read some documents about tuning hashtables for further reference.
+	#
+	HashSize 32768
+
+	#
+	# Maximum number of conntracks, it should be double of: 
+	# $ cat /proc/sys/net/netfilter/nf_conntrack_max
+	# since the daemon may keep some dead entries cached for possible
+	# retransmission during state synchronization.
+	#
+	HashLimit 131072
+
+	#
+	# Logfile: on (/var/log/conntrackd.log), off, or a filename
+	# Default: off
+	#
+	LogFile on
+
+	#
+	# Syslog: on, off or a facility name (daemon (default) or local0..7)
+	# Default: off
+	#
+	#Syslog on
+
+	#
+	# Lockfile
+	# 
+	LockFile /var/lock/conntrack.lock
+
+	#
+	# Unix socket configuration
+	#
+	UNIX {
+		Path /var/run/conntrackd.ctl
+		Backlog 20
+	}
+
+	#
+	# Netlink event socket buffer size. If you do not specify this clause,
+	# the default buffer size value in /proc/net/core/rmem_default is
+	# used. This default value is usually around 100 Kbytes which is
+	# fairly small for busy firewalls. This leads to event message dropping
+	# and high CPU consumption. This example configuration file sets the
+	# size to 2 MBytes to avoid this sort of problems.
+	#
+	NetlinkBufferSize 2097152
+
+	#
+	# The daemon doubles the size of the netlink event socket buffer size
+	# if it detects netlink event message dropping. This clause sets the
+	# maximum buffer size growth that can be reached. This example file
+	# sets the size to 8 MBytes.
+	#
+	NetlinkBufferSizeMaxGrowth 8388608
+
+	#
+	# If the daemon detects that Netlink is dropping state-change events,
+	# it automatically schedules a resynchronization against the Kernel
+	# after 30 seconds (default value). Resynchronizations are expensive
+	# in terms of CPU consumption since the daemon has to get the full
+	# kernel state-table and purge state-entries that do not exist anymore.
+	# Be careful of setting a very small value here. You have the following
+	# choices: On (enabled, use default 30 seconds value), Off (disabled)
+	# or Value (in seconds, to set a specific amount of time). If not
+	# specified, the daemon assumes that this option is enabled.
+	#
+	# NetlinkOverrunResync On
+
+	# If you want reliable event reporting over Netlink, set on this
+	# option. If you set on this clause, it is a good idea to set off
+	# NetlinkOverrunResync. This option is off by default and you need
+	# a Linux kernel >= 2.6.31.
+	#
+	# NetlinkEventsReliable Off
+
+	# 
+	# By default, the daemon receives state updates following an
+	# event-driven model. You can modify this behaviour by switching to
+	# polling mode with the PollSecs clause. This clause tells conntrackd
+	# to dump the states in the kernel every N seconds. With regards to
+	# synchronization mode, the polling mode can only guarantee that
+	# long-lifetime states are recovered. The main advantage of this method
+	# is the reduction in the state replication at the cost of reducing the
+	# chances of recovering connections.
+	#
+	# PollSecs 15
+
+	#
+	# The daemon prioritizes the handling of state-change events coming
+	# from the core. With this clause, you can set the maximum number of
+	# state-change events (those coming from kernel-space) that the daemon
+	# will handle after which it will handle other events coming from the
+	# network or userspace. A low value improves interactivity (in terms of
+	# real-time behaviour) at the cost of extra CPU consumption.
+	# Default (if not set) is 100.
+	#
+	# EventIterationLimit 100
+
+	#
+	# Event filtering: This clause allows you to filter certain traffic,
+	# There are currently three filter-sets: Protocol, Address and
+	# State. The filter is attached to an action that can be: Accept or
+	# Ignore. Thus, you can define the event filtering policy of the
+	# filter-sets in positive or negative logic depending on your needs.
+	# You can select if conntrackd filters the event messages from 
+	# user-space or kernel-space. The kernel-space event filtering
+	# saves some CPU cycles by avoiding the copy of the event message
+	# from kernel-space to user-space. The kernel-space event filtering
+	# is prefered, however, you require a Linux kernel >= 2.6.29 to
+	# filter from kernel-space. If you want to select kernel-space 
+	# event filtering, use the keyword 'Kernelspace' instead of 
+	# 'Userspace'.
+	#
+	Filter From Userspace {
+		#
+		# Accept only certain protocols: You may want to replicate
+		# the state of flows depending on their layer 4 protocol.
+		#
+		Protocol Accept {
+			TCP
+			SCTP
+			DCCP
+			# ICMP # This requires a Linux kernel >= 2.6.31
+		}
+
+		#
+		# Ignore traffic for a certain set of IP's: Usually all the
+		# IP assigned to the firewall since local traffic must be
+		# ignored, only forwarded connections are worth to replicate.
+		# Note that these values depends on the local IPs that are
+		# assigned to the firewall.
+		#
+		Address Ignore {
+			IPv4_address 127.0.0.1 # loopback
+			IPv4_address 192.168.0.100 # virtual IP 1
+			IPv4_address 192.168.1.100 # virtual IP 2
+			IPv4_address 192.168.0.1
+			IPv4_address 192.168.1.1
+			IPv4_address 192.168.100.100 # dedicated link ip
+			#
+			# You can also specify networks in format IP/cidr.
+			# IPv4_address 192.168.0.0/24
+			#
+			# You can also specify an IPv6 address
+			# IPv6_address ::1
+		}
+
+		#
+		# Uncomment this line below if you want to filter by flow state.
+		# This option introduces a trade-off in the replication: it
+		# reduces CPU consumption at the cost of having lazy backup 
+		# firewall replicas. The existing TCP states are: SYN_SENT,
+		# SYN_RECV, ESTABLISHED, FIN_WAIT, CLOSE_WAIT, LAST_ACK,
+		# TIME_WAIT, CLOSED, LISTEN.
+		#
+		# State Accept {
+		#	ESTABLISHED CLOSED TIME_WAIT CLOSE_WAIT for TCP
+		# }
+	}
+}
diff --git a/doc/sync/primary-backup.sh b/doc/sync/primary-backup.sh
new file mode 100755
index 0000000..34c1cfa
--- /dev/null
+++ b/doc/sync/primary-backup.sh
@@ -0,0 +1,124 @@
+#!/bin/sh
+# 
+# (C) 2008 by Pablo Neira Ayuso <pablo@netfilter.org>
+#
+# This software may be used and distributed according to the terms
+# of the GNU General Public License, incorporated herein by reference.
+#
+# Description:
+#
+# This is the script for primary-backup setups for keepalived
+# (http://www.keepalived.org). You may adapt it to make it work with other
+# high-availability managers.
+#
+# Do not forget to include the required modifications to your keepalived.conf
+# file to invoke this script during keepalived's state transitions.
+#
+# Contributions to improve this script are welcome :).
+#
+
+CONNTRACKD_BIN=/usr/sbin/conntrackd
+CONNTRACKD_LOCK=/var/lock/conntrack.lock
+CONNTRACKD_CONFIG=/etc/conntrackd/conntrackd.conf
+
+case "$1" in
+  primary)
+    #
+    # commit the external cache into the kernel table
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -c
+    if [ $? -eq 1 ]
+    then
+        logger "ERROR: failed to invoke conntrackd -c"
+    fi
+
+    #
+    # flush the internal and the external caches
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -f
+    if [ $? -eq 1 ]
+    then
+    	logger "ERROR: failed to invoke conntrackd -f"
+    fi
+
+    #
+    # resynchronize my internal cache to the kernel table
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -R
+    if [ $? -eq 1 ]
+    then
+    	logger "ERROR: failed to invoke conntrackd -R"
+    fi
+
+    #
+    # send a bulk update to backups 
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -B
+    if [ $? -eq 1 ]
+    then
+        logger "ERROR: failed to invoke conntrackd -B"
+    fi
+    ;;
+  backup)
+    #
+    # is conntrackd running? request some statistics to check it
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -s
+    if [ $? -eq 1 ]
+    then
+        #
+	# something's wrong, do we have a lock file?
+	#
+    	if [ -f $CONNTRACKD_LOCK ]
+	then
+	    logger "WARNING: conntrackd was not cleanly stopped."
+	    logger "If you suspect that it has crashed:"
+	    logger "1) Enable coredumps"
+	    logger "2) Try to reproduce the problem"
+	    logger "3) Post the coredump to netfilter-devel@vger.kernel.org"
+	    rm -f $CONNTRACKD_LOCK
+	fi
+	$CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -d
+	if [ $? -eq 1 ]
+	then
+	    logger "ERROR: cannot launch conntrackd"
+	    exit 1
+	fi
+    fi
+    #
+    # shorten kernel conntrack timers to remove the zombie entries.
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -t
+    if [ $? -eq 1 ]
+    then
+    	logger "ERROR: failed to invoke conntrackd -t"
+    fi
+
+    #
+    # request resynchronization with master firewall replica (if any)
+    # Note: this does nothing in the alarm approach.
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -n
+    if [ $? -eq 1 ]
+    then
+    	logger "ERROR: failed to invoke conntrackd -n"
+    fi
+    ;;
+  fault)
+    #
+    # shorten kernel conntrack timers to remove the zombie entries.
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -t
+    if [ $? -eq 1 ]
+    then
+    	logger "ERROR: failed to invoke conntrackd -t"
+    fi
+    ;;
+  *)
+    logger "ERROR: unknown state transition"
+    echo "Usage: primary-backup.sh {primary|backup|fault}"
+    exit 1
+    ;;
+esac
+
+exit 0