bgp: change comand order, add route filterig

* bgp: change comand order, add route filterig

Placed upper more often used commands;
Add route filtering;
Add confederation commands;
Add route dampening.

1 files changed, 405 insertions, 228 deletions

diff --git a/docs/configuration/protocols/bgp.rst b/docs/configuration/protocols/bgp.rst
index ae7eb795..27858224 100644
--- a/docs/configuration/protocols/bgp.rst
+++ b/docs/configuration/protocols/bgp.rst
@@ -28,7 +28,9 @@ From :rfc:`1930`:
 Each AS has an identifying number associated with it called an :abbr:`ASN
 (Autonomous System Number)`. This is a two octet value ranging in value from 1
 to 65535. The AS numbers 64512 through 65535 are defined as private AS numbers.
-Private AS numbers must not be advertised on the global Internet.
+Private AS numbers must not be advertised on the global Internet. The 2-byte AS
+number range has been exhausted. 4-byte AS numbers are specified in
+ :rfc:`6793`, and provide a pool of 4294967296 AS numbers.
 
 The :abbr:`ASN (Autonomous System Number)` is one of the essential elements of
 BGP. BGP is a distance vector routing protocol, and the AS-Path framework
@@ -156,200 +158,11 @@ connection.
 BGP Router Configuration
 ========================
 
-ASN and Router ID
------------------
-
-.. cfgcmd:: set protocols bgp <asn>
-
-   First of all you must configure BGP router with the :abbr:`ASN (Autonomous
-   System Number)`. The AS number is an identifier for the autonomous system.
-   The BGP protocol uses the AS number for detecting whether the BGP connection
-   is internal or external.
-
-.. cfgcmd:: set protocols bgp <asn> parameters router-id
-
-   This command specifies the router-ID. If router ID is not specified it will
-   use the highest interface IP address.
-
-Route Selection
----------------
-
-.. cfgcmd:: set protocols bgp <asn> parameters always-compare-med
-
-   This command provides to compare the MED on routes, even when they were 
-   received from different neighbouring ASes. Setting this option makes the 
-   order of preference of routes more defined, and should eliminate MED 
-   induced oscillations.
-
-.. cfgcmd:: set protocols bgp <asn> parameters bestpath as-path confed
-
-   This command specifies that the length of confederation path sets and
-   sequences should be taken into account during the BGP best path
-   decision process.
-
-.. cfgcmd:: set protocols bgp <asn> parameters bestpath as-path multipath-relax
-
-   This command specifies that BGP decision process should consider paths
-   of equal AS_PATH length candidates for multipath computation. Without
-   the knob, the entire AS_PATH must match for multipath computation.
-
-.. cfgcmd:: set protocols bgp <asn> parameters bestpath as-path ignore
-
-   Ignore AS_PATH length when selecting a route
-
-.. cfgcmd:: set protocols bgp <asn> parameters bestpath compare-routerid
-
-   Ensure that when comparing routes where both are equal on most metrics, 
-   including local-pref, AS_PATH length, IGP cost, MED, that the tie is 
-   broken based on router-ID.
-
-   If this option is enabled, then the already-selected check, where 
-   already selected eBGP routes are preferred, is skipped.
-
-   If a route has an ORIGINATOR_ID attribute because it has been reflected, 
-   that ORIGINATOR_ID will be used. Otherwise, the router-ID of the peer 
-   the route was received from will be used.
-
-   The advantage of this is that the route-selection (at this point) will 
-   be more deterministic. The disadvantage is that a few or even one lowest-ID 
-   router may attract all traffic to otherwise-equal paths because of this 
-   check. It may increase the possibility of MED or IGP oscillation, unless 
-   other measures were taken to avoid these. The exact behaviour will be 
-   sensitive to the iBGP and reflection topology.
-
-.. cfgcmd:: set protocols bgp <asn> parameters bestpath med confed
-   
-   This command specifies that BGP considers the MED when comparing routes 
-   originated from different sub-ASs within the confederation to which this 
-   BGP speaker belongs. The default state, where the MED attribute is not 
-   considered.
-
-.. cfgcmd:: set protocols bgp <asn> parameters bestpath med missing-as-worst
-
-   This command specifies that a route with a MED is always considered to be 
-   better than a route without a MED by causing the missing MED attribute to 
-   have a value of infinity. The default state, where the missing MED 
-   attribute is considered to have a value of zero.
-
-.. cfgcmd:: set protocols bgp <asn> parameters default local-pref
-   <local-pref value>
-
-   This command specifies the default local preference value. The local 
-   preference range is 0 to 4294967295.
-   
-.. cfgcmd:: set protocols bgp <asn> parameters deterministic-med
-
-   This command provides to compare different MED values that advertised by 
-   neighbours in the same AS for routes selection. When this command is enabled, 
-   routes from the same autonomous system are grouped together, and the best 
-   entries of each group are compared.
-
-Administrative Distance
------------------------
-
-.. cfgcmd:: set protocols bgp <asn> parameters distance global
-   <external|internal|local> <distance>
-
-   This command change distance value of BGP. The arguments are the distance 
-   values for external routes, internal routes and local routes respectively.
-   The distance range is 1 to 255.
-
-.. cfgcmd:: set protocols bgp <asn> parameters distance prefix <subnet> distance
-   <distance>
-
-   This command sets the administrative distance for a particular route. The 
-   distance range is 1 to 255.
-   
-   .. note:: Routes with a distance of 255 are effectively disabled and not
-      installed into the kernel.
-
-Network Advertisement
----------------------
-
-.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
-   network <prefix>
-
-   This command is used for advertising IPv4 or IPv6 networks.
-   
-   .. note:: By default, the BGP prefix is advertised even if it's not present 
-      in the routing table. This behaviour differs from the implementation of
-      some vendors.
-   
-.. cfgcmd:: set protocols bgp <asn> parameters network-import-check
-
-   This configuration modifies the behavior of the network statement. If you 
-   have this configured the underlying network must exist in the routing table.
-
-.. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> address-family
-   <ipv4-unicast|ipv6-unicast> default-originate [route-map <name>]
-
-   By default, VyOS does not advertise a default route (0.0.0.0/0) even if it is
-   in routing table. When you want to announce default routes to the peer, use
-   this command. Using optional argument :cfgcmd:`route-map` you can inject the
-   default route to given neighbor only if the conditions in the route map are
-   met.
-
-Route Aggregation
------------------
-
-.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
-   aggregate-address <prefix>
-
-   This command specifies an aggregate address. The router will also 
-   announce longer-prefixes inside of the aggregate address.
-
-.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
-   aggregate-address <prefix> as-set
-
-   This command specifies an aggregate address with a mathematical set of 
-   autonomous systems. This command summarizes the AS_PATH attributes of 
-   all the individual routes. 
-
-.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
-   aggregate-address <prefix> summary-only
-
-   This command specifies an aggregate address and provides that 
-   longer-prefixes inside of the aggregate address are suppressed 
-   before sending BGP updates out to peers.
-
-Redistribution
---------------
-
-.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
-   redistribute connected
-
-   Redistribute connected routes to BGP process.
-
-.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
-   redistribute kernel
-
-   Redistribute kernel routes to BGP process.
-
-.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
-   redistribute ospf
-
-   Redistribute OSPF routes to BGP process.
-
-.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
-   redistribute rip
-
-   Redistribute RIP routes to BGP process.
-
-.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
-   redistribute static
-
-   Redistribute static routes to BGP process.
-
-.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
-   redistribute <route source> metric <number>
-
-   This command specifies metric (MED) for redistributed routes. The 
-   metric range is 0 to 4294967295.
-
-.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
-   redistribute <route source> route-map <name>
-
-   This command allows to use route map to filter redistributed routes.
+First of all you must configure BGP router with the :abbr:`ASN (Autonomous
+System Number)`. The AS number is an identifier for the autonomous system.
+The BGP protocol uses the AS number for detecting whether the BGP connection
+is internal or external. VyOS does not have a special command to start the BGP
+process. The BGP process starts when the first neighbor is configured.
 
 Peers Configuration
 -------------------
@@ -360,7 +173,7 @@ Defining Peers
 .. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> remote-as 
    <nasn>
 
-   This command creates a new neighbor whose remote-as is NASN. The neighbor 
+   This command creates a new neighbor whose remote-as is <nasn>. The neighbor
    address can be an IPv4 address or an IPv6 address or an interface to use 
    for the connection. The command it applicable for peer and peer group.
 
@@ -368,7 +181,7 @@ Defining Peers
    internal
 
    Create a peer as you would when you specify an ASN, except that if the 
-   peers ASN is different than mine as specified under the :cfgcmd:`protocols 
+   peers ASN is different than mine as specified under the :cfgcmd:`protocols
    bgp <asn>` command the connection will be denied.
 
 .. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> remote-as
@@ -391,9 +204,10 @@ Defining Peers
 .. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> update-source
    <address|interface>
 
-   Specify the IPv4 source address to use for the BGP session to this neighbour,
+   Specify the IPv4 source address to use for the BGP session to this neighbor,
    may be specified as either an IPv4 address directly or as an interface name.
 
+
 Capability Negotiation
 ^^^^^^^^^^^^^^^^^^^^^^
 
@@ -451,6 +265,7 @@ Capability Negotiation
    Capability Negotiation. Please use :cfgcmd:`disable-capability-negotiation` 
    command to disable the feature.
 
+
 Peer Parameters
 ^^^^^^^^^^^^^^^
 
@@ -489,22 +304,6 @@ Peer Parameters
    advertisements sent to a peer or peer group.
 
 .. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> address-family
-   <ipv4-unicast|ipv6-unicast> distribute-list <export|import> <number>
-
-   This command applys the access list filters named in <number> to the
-   specified BGP neighbor to restrict the routing information that BGP learns
-   and/or advertises. The arguments :cfgcmd:`export` and :cfgcmd:`import`
-   specify the direction in which the prefix lists are applied.
-
-.. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> address-family
-   <ipv4-unicast|ipv6-unicast> filter-list <export|import> <name>
-   
-   This command applys the AS path access list filters named in <name> to the
-   specified BGP neighbor to restrict the routing information that BGP learns
-   and/or advertises. The arguments :cfgcmd:`export` and :cfgcmd:`import`
-   specify the direction in which the prefix lists are applied.
-
-.. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> address-family
    <ipv4-unicast|ipv6-unicast> maximum-prefix <number>
 
    This command specifies a maximum number of prefixes we can receive 
@@ -566,6 +365,12 @@ Peer Parameters
 
    This command allows peerings between directly connected eBGP peers 
    using loopback addresses without adjusting the default TTL of 1.
+   
+.. cfgcmd:: set protocols bgp <asn> neighbor <address|interface>
+   disable-send-community <extended|standard>
+   
+   This command specifies that the community attribute should not be sent
+   in route updates to a peer. By default community attribute is sent.
 
 .. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> ebgp-multihop
    <number>
@@ -598,6 +403,12 @@ Peer Parameters
 
    Configures the BGP speaker so that it only accepts inbound connections 
    from, but does not initiate outbound connections to the peer or peer group.
+   
+.. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> password
+   <text>
+
+   This command specifies a MD5 password to be used with the tcp socket that
+   is being used to connect to the remote peer.
 
 .. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> ttl-security
    hops <number>
@@ -608,6 +419,7 @@ Peer Parameters
    become neighbors. The number of hops range is 1 to 254. This 
    command is mutually exclusive with :cfgcmd:`ebgp-multihop`.   
 
+
 Peer Groups
 ^^^^^^^^^^^
 
@@ -632,9 +444,100 @@ are treated as belonging to a default peer group, and will share updates.
 
    This command bind specific peer to peer group with a given name.
 
-General configuration
+
+Network Advertisement Configuration
+-----------------------------------
+
+.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
+   network <prefix>
+
+   This command is used for advertising IPv4 or IPv6 networks.
+   
+   .. note:: By default, the BGP prefix is advertised even if it's not present 
+      in the routing table. This behaviour differs from the implementation of
+      some vendors.
+   
+.. cfgcmd:: set protocols bgp <asn> parameters network-import-check
+
+   This configuration modifies the behavior of the network statement. If you 
+   have this configured the underlying network must exist in the routing table.
+
+.. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> address-family
+   <ipv4-unicast|ipv6-unicast> default-originate [route-map <name>]
+
+   By default, VyOS does not advertise a default route (0.0.0.0/0) even if it is
+   in routing table. When you want to announce default routes to the peer, use
+   this command. Using optional argument :cfgcmd:`route-map` you can inject the
+   default route to given neighbor only if the conditions in the route map are
+   met.
+
+
+Route Aggregation Configuration
+-------------------------------
+
+.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
+   aggregate-address <prefix>
+
+   This command specifies an aggregate address. The router will also 
+   announce longer-prefixes inside of the aggregate address.
+
+.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
+   aggregate-address <prefix> as-set
+
+   This command specifies an aggregate address with a mathematical set of 
+   autonomous systems. This command summarizes the AS_PATH attributes of 
+   all the individual routes. 
+
+.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
+   aggregate-address <prefix> summary-only
+
+   This command specifies an aggregate address and provides that 
+   longer-prefixes inside of the aggregate address are suppressed 
+   before sending BGP updates out to peers.
+
+.. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> address-family
+   <ipv4-unicast|ipv6-unicast> unsuppress-map <name>
+   
+   This command applies route-map to selectively unsuppress prefixes
+   suppressed by summarisation.
+
+
+Redistribution Configuration
+----------------------------
+
+.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
+   redistribute <route source>
+
+   This command redistributes routing information from the given route source
+   to the BGP process. There are six modes available for route source: bgp,
+   connected, kernel, ospf, rip, static.
+
+.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
+   redistribute <route source> metric <number>
+
+   This command specifies metric (MED) for redistributed routes. The 
+   metric range is 0 to 4294967295. There are six modes available for 
+   route source: bgp, connected, kernel, ospf, rip, static.
+
+.. cfgcmd:: set protocols bgp <asn> address-family <ipv4-unicast|ipv6-unicast>
+   redistribute <route source> route-map <name>
+
+   This command allows to use route map to filter redistributed routes.
+   There are six modes available for route source: bgp, connected, kernel,
+   ospf, rip, static.
+
+
+General Configuration
 ---------------------
 
+Common parametrs
+^^^^^^^^^^^^^^^^
+
+.. cfgcmd:: set protocols bgp <asn> parameters router-id <id>
+
+   This command specifies the router-ID. If router ID is not specified it will
+   use the highest interface IP address.
+
 .. cfgcmd:: set protocols bgp <asn> maximum-paths <ebgp|ibgp> <number>
 
    This command defines the maximum number of parallel routes that 
@@ -657,38 +560,278 @@ General configuration
    Tis command disables route reflection between route reflector clients.
    By default, the clients of a route reflector are not required to be 
    fully meshed and the routes from a client are reflected to other clients. 
-   However, if the clients are fully meshed, route reflection is not required. 
-   In this case, use the :cfgcmd:`no-client-to-client-reflection` command 
+   However, if the clients are fully meshed, route reflection is not required.
+   In this case, use the :cfgcmd:`no-client-to-client-reflection` command
    to disable client-to-client reflection.
 
 .. cfgcmd:: set protocols bgp <asn> parameters no-fast-external-failover
    
    Disable immediate sesison reset if peer's connected link goes down.
 
+
+Administrative Distance
+^^^^^^^^^^^^^^^^^^^^^^^
+
+.. cfgcmd:: set protocols bgp <asn> parameters distance global
+   <external|internal|local> <distance>
+
+   This command change distance value of BGP. The arguments are the distance
+   values for external routes, internal routes and local routes respectively.
+   The distance range is 1 to 255.
+
+.. cfgcmd:: set protocols bgp <asn> parameters distance prefix <subnet>
+   distance <distance>
+
+   This command sets the administrative distance for a particular route. The
+   distance range is 1 to 255.
+   
+   .. note:: Routes with a distance of 255 are effectively disabled and not
+      installed into the kernel.
+
+
 Timers
 ^^^^^^
 
 .. cfgcmd:: set protocols bgp <asn> timers holdtime <seconds>
 
-   This command specifies hold-time in seconds. The timer can 
-   range from 4 to 65535.The default value is 180 second. If
-   you set value to 0 VyOS will not hold routes.
+   This command specifies hold-time in seconds. The timer range is
+   4 to 65535. The default value is 180 second. If you set value to 0
+   VyOS will not hold routes.
    
 .. cfgcmd:: set protocols bgp <asn> timers keepalive <seconds>
 
    This command specifies keep-alive time in seconds. The timer 
-   can range from 4 to 65535.The default value is 60 second.
+   can range from 4 to 65535. The default value is 60 second.
 
-Route Reflector Configuration
+
+Route Dampening
+^^^^^^^^^^^^^^^
+
+When a route fails, a routing update is sent to withdraw the route from the
+network's routing tables. When the route is re-enabled, the change in
+availability is also advertised. A route that continually fails and returns
+requires a great deal of network traffic to update the network about the
+route's status.
+
+Route dampening wich described in :rfc:`2439` enables you to identify routes
+that repeatedly fail and return. If route dampening is enabled, an unstable
+route accumulates penalties each time the route fails and returns. If the
+accumulated penalties exceed a threshold, the route is no longer advertised.
+This is route suppression. Routes that have been suppressed are re-entered
+into the routing table only when the amount of their penalty falls below a
+threshold.
+
+A penalty of 1000 is assessed each time the route fails. When the penalties
+reach a predefined threshold (suppress-value), the router stops advertising
+the route.
+
+Once a route is assessed a penalty, the penalty is decreased by half each time
+a predefined amount of time elapses (half-life-time). When the accumulated
+penalties fall below a predefined threshold (reuse-value), the route is
+unsuppressed and added back into the BGP routing table.
+
+No route is suppressed indefinitely. Maximum-suppress-time defines the maximum
+time a route can be suppressed before it is re-advertised. 
+
+.. cfgcmd:: set protocols bgp <asn> parameters dampening
+   half-life <minutes>
+
+   This command defines the amount of time in minutes after
+   which a penalty is reduced by half. The timer range is
+   10 to 45 minutes. 
+
+.. cfgcmd:: set protocols bgp <asn> parameters dampening
+   re-use <seconds>
+	
+   This command defines the accumulated penalty amount at which the
+   route is re-advertised. The penalty range is 1 to 20000.
+	
+.. cfgcmd:: set protocols bgp <asn> parameters dampening 
+   start-suppress-time <seconds>
+
+   This command defines the accumulated penalty amount at which the
+   route is suppressed. The penalty range is 1 to 20000.
+
+.. cfgcmd:: set protocols bgp <asn> parameters dampening 
+   max-suppress-time <seconds>
+
+   This command defines the maximum time in minutes that a route is
+   suppressed. The timer range is 1 to 255 minutes.
+
+
+Route Selection Configuration
+-----------------------------
+
+.. cfgcmd:: set protocols bgp <asn> parameters always-compare-med
+
+   This command provides to compare the MED on routes, even when they were 
+   received from different neighbouring ASes. Setting this option makes the 
+   order of preference of routes more defined, and should eliminate MED 
+   induced oscillations.
+
+.. cfgcmd:: set protocols bgp <asn> parameters bestpath as-path confed
+
+   This command specifies that the length of confederation path sets and
+   sequences should be taken into account during the BGP best path
+   decision process.
+
+.. cfgcmd:: set protocols bgp <asn> parameters bestpath as-path multipath-relax
+
+   This command specifies that BGP decision process should consider paths
+   of equal AS_PATH length candidates for multipath computation. Without
+   the knob, the entire AS_PATH must match for multipath computation.
+
+.. cfgcmd:: set protocols bgp <asn> parameters bestpath as-path ignore
+
+   Ignore AS_PATH length when selecting a route
+
+.. cfgcmd:: set protocols bgp <asn> parameters bestpath compare-routerid
+
+   Ensure that when comparing routes where both are equal on most metrics, 
+   including local-pref, AS_PATH length, IGP cost, MED, that the tie is 
+   broken based on router-ID.
+
+   If this option is enabled, then the already-selected check, where 
+   already selected eBGP routes are preferred, is skipped.
+
+   If a route has an ORIGINATOR_ID attribute because it has been reflected, 
+   that ORIGINATOR_ID will be used. Otherwise, the router-ID of the peer 
+   the route was received from will be used.
+
+   The advantage of this is that the route-selection (at this point) will 
+   be more deterministic. The disadvantage is that a few or even one lowest-ID
+   router may attract all traffic to otherwise-equal paths because of this 
+   check. It may increase the possibility of MED or IGP oscillation, unless 
+   other measures were taken to avoid these. The exact behaviour will be 
+   sensitive to the iBGP and reflection topology.
+
+.. cfgcmd:: set protocols bgp <asn> parameters bestpath med confed
+   
+   This command specifies that BGP considers the MED when comparing routes 
+   originated from different sub-ASs within the confederation to which this 
+   BGP speaker belongs. The default state, where the MED attribute is not 
+   considered.
+
+.. cfgcmd:: set protocols bgp <asn> parameters bestpath med missing-as-worst
+
+   This command specifies that a route with a MED is always considered to be 
+   better than a route without a MED by causing the missing MED attribute to 
+   have a value of infinity. The default state, where the missing MED 
+   attribute is considered to have a value of zero.
+
+.. cfgcmd:: set protocols bgp <asn> parameters default local-pref
+   <local-pref value>
+
+   This command specifies the default local preference value. The local 
+   preference range is 0 to 4294967295.
+   
+.. cfgcmd:: set protocols bgp <asn> parameters deterministic-med
+
+   This command provides to compare different MED values that advertised by 
+   neighbours in the same AS for routes selection. When this command is
+   enabled, routes from the same autonomous system are grouped together, and
+   the best entries of each group are compared.
+
+.. cfgcmd:: set protocols bgp <asn> address-family ipv4-unicast network
+   <prefix> backdoor
+
+   This command allows the router to prefer route to specified prefix learned
+   via IGP through backdoor link instead of a route to the same prefix learned
+   via EBGP.
+
+
+Route Filtering Configuration
 -----------------------------
 
+In order to control and modify routing information that is exchanged between
+peers you can use route-map, filter-list, prefix-list, distribute-list. 
+
+For inbound updates the order of preference is:
+
+  - route-map
+  - filter-list
+  - prefix-list, distribute-list
+
+For outbound updates the order of preference is:
+
+  - prefix-list, distribute-list
+  - filter-list
+  - route-map
+
+  .. note:: The attributes :cfgcmd:`prefix-list` and :cfgcmd:`distribute-list`
+     are mutually exclusive, and only one command (distribute-list or 
+     prefix-list) can be applied to each inbound or outbound direction for a 
+     particular neighbor.
+
+.. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> address-family
+   <ipv4-unicast|ipv6-unicast> distribute-list <export|import> <number>
+
+   This command applys the access list filters named in <number> to the
+   specified BGP neighbor to restrict the routing information that BGP learns
+   and/or advertises. The arguments :cfgcmd:`export` and :cfgcmd:`import`
+   specify the direction in which the access list are applied.
+   
+.. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> address-family
+   <ipv4-unicast|ipv6-unicast> prefix-list <export|import> <name>
+
+   This command applys the prfefix list filters named in <name> to the
+   specified BGP neighbor to restrict the routing information that BGP learns
+   and/or advertises. The arguments :cfgcmd:`export` and :cfgcmd:`import`
+   specify the direction in which the prefix list are applied.
+
+.. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> address-family
+   <ipv4-unicast|ipv6-unicast> route-map <export|import> <name>
+
+   This command applys the route map named in <name> to the specified BGP
+   neighbor to control and modify routing information that is exchanged
+   between peers. The arguments :cfgcmd:`export` and :cfgcmd:`import`
+   specify the direction in which the route map are applied.
+
+.. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> address-family
+   <ipv4-unicast|ipv6-unicast> filter-list <export|import> <name>
+   
+   This command applys the AS path access list filters named in <name> to the
+   specified BGP neighbor to restrict the routing information that BGP learns
+   and/or advertises. The arguments :cfgcmd:`export` and :cfgcmd:`import`
+   specify the direction in which the AS path access list are applied.
+   
+.. cfgcmd:: set protocols bgp <asn> neighbor <address|interface> address-family
+   <ipv4-unicast|ipv6-unicast> capability orf <receive|send>
+   
+   This command enables the ORF capability (described in :rfc:`5291`) on the
+   local router, and enables ORF capability advertisement to the specified BGP
+   peer. The :cfgcmd:`receive` keyword configures a router to advertise ORF
+   receive capabilities. The :cfgcmd:`send` keyword configures a router to
+   advertise ORF send capabilities. To advertise a filter from a sender, you
+   must create an IP prefix list for the specified BGP peer applied in inbound
+   derection.
+
+
+BGP Scaling Configuration
+-------------------------
+
 BGP routers connected inside the same AS through BGP belong to an internal BGP
-session, or IBGP. In order to prevent routing table loops, IBGP speaker does not
-advertise IBGP-learned routes to other IBGP speaker (Split Horizon mechanism).
-As such, IBGP requires a full mesh of all peers. For large networks, this
-quickly becomes unscalable. Introducing route reflectors removes the need for
-the full-mesh. Route reflectors mechanism is described in :rfc:`4456` and
-updated by :rfc:`7606`.
+session, or IBGP. In order to prevent routing table loops, IBGP speaker does
+not advertise IBGP-learned routes to other IBGP speaker (Split Horizon
+mechanism). As such, IBGP requires a full mesh of all peers. For large
+networks, this quickly becomes unscalable.
+
+There are two ways that help us to mitigate the BGPs full-mesh requirement in
+a network:
+   
+   - Using BGP route-reflectors
+   - Using BGP confederation
+
+
+Route Reflector Configuration
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Introducing route reflectors removes the need for the full-mesh. When you
+configure a route reflector you have to tell the router whether the other IBGP
+router is a client or non-client. A client is an IBGP router that the route
+reflector will “reflect” routes to, the non-client is just a regular IBGP
+neighbor. Route reflectors mechanism is described in :rfc:`4456` and updated
+by :rfc:`7606`.
 
 .. cfgcmd:: set protocols bgp <asn> neighbor <address> address-family
    <ipv4-unicast|ipv6-unicast> route-reflector-client
@@ -703,6 +846,30 @@ updated by :rfc:`7606`.
    set to an arbitrary 32-bit value. 
 
 
+Confederation Configuration
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+A BGP confederation divides our AS into sub-ASes to reduce the number of
+required IBGP peerings. Within a sub-AS we still require full-mesh IBGP but
+between these sub-ASes we use something that looks like EBGP but behaves like
+IBGP (called confederation BGP). Confederation mechanism is described in
+:rfc:`5065`
+
+.. cfgcmd:: set protocols bgp <subasn> parameters confederation identifier
+   <asn>
+
+   This command specifies a BGP confederation identifier. <asn> is the number
+   of the autonomous system that internally includes multiple sub-autonomous
+   systems (a confederation). <subasn> is the number sub-autonomous system
+   inside <asn>.
+
+.. cfgcmd:: set protocols bgp <subasn> parameters confederation confederation
+   peers <nsubasn>
+
+   This command sets other confederations <nsubasn> as members of autonomous
+   system specified by :cfgcmd:`confederation identifier <asn>`.
+
+
 Operational Mode Commands
 =========================
 
@@ -764,6 +931,15 @@ Show
 
    This command displays BGP dampened routes.
 
+.. opcmd:: show ip bgp flap-statistics
+
+   This command displays information about flapping BGP routes.
+   
+.. opcmd:: show ip bgp filter-list <name>
+
+   This command displays BGP routes allowed by by the specified AS Path
+   access list.
+
 .. opcmd:: show <ip|ipv6> bgp neighbors <address> advertised-routes
 
    This command displays BGP routes advertised to a neighbor.
@@ -837,6 +1013,7 @@ Reset
    you do not specify the :cfgcmd:`in` or :cfgcmd:`out` options, both 
    inbound and outbound soft reconfiguration are triggered.
 
+
 Configuration Examples
 ----------------------