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author | Peter Magnusson <peter@wselcon.se> | 2019-04-25 15:12:22 +0200 |
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committer | Peter Magnusson <peter@wselcon.se> | 2019-04-25 15:12:22 +0200 |
commit | beb0978da3cc58da96d30911893add6849baf663 (patch) | |
tree | f335a292b0417983925374e4c076eb0a46e4a150 /docs/examples/zone-policy.rst | |
parent | f5008037d4d0ebd479944d05f8f26bd01cbf6767 (diff) | |
download | vyos-documentation-beb0978da3cc58da96d30911893add6849baf663.tar.gz vyos-documentation-beb0978da3cc58da96d30911893add6849baf663.zip |
Add the zone-example from wiki
Diffstat (limited to 'docs/examples/zone-policy.rst')
-rw-r--r-- | docs/examples/zone-policy.rst | 379 |
1 files changed, 379 insertions, 0 deletions
diff --git a/docs/examples/zone-policy.rst b/docs/examples/zone-policy.rst new file mode 100644 index 00000000..d159d02d --- /dev/null +++ b/docs/examples/zone-policy.rst @@ -0,0 +1,379 @@ +.. _examples-zone-policy: + +Zone-Policy example +------------------- + +Native IPv4 and IPv6 +^^^^^^^^^^^^^^^^^^^^ + +We have three networks. + +.. code-block:: sh + + WAN - 172.16.10.0/24, 2001:0DB8:0:9999::0/64 + LAN - 192.168.100.0/24, 2001:0DB8:0:AAAA::0/64 + DMZ - 192.168.200.0/24, 2001:0DB8:0:BBBB::0/64 + + +This specific example is for a router on a stick, but is very easily adapted +for however many NICs you have. + +[http://imgur.com/Alz1J.png Topology Image] + +The VyOS interface is assigned the .1/:1 address of their respective networks. +WAN is on VLAN 10, LAN on VLAN 20, and DMZ on VLAN 30. + +It will look something like this: + +.. code-block:: sh + + interfaces { + ethernet eth0 { + duplex auto + hw-id 00:0c:29:6e:2a:92 + smp_affinity auto + speed auto + vif 10 { + address 172.16.10.1/24 + address 2001:db8:0:9999::1/64 + } + vif 20 { + address 192.168.100.1/24 + address 2001:db8:0:AAAA::1/64 + } + vif 30 { + address 192.168.200.1/24 + address 2001:db8:0:BBBB::1/64 + } + } + loopback lo { + } + } + + +Zones Basics +^^^^^^^^^^^^ + +Each interface is assigned to a zone. The interface can be physical or virtual +such as tunnels (VPN, pptp, gre, etc) and are treated exactly the same. + +Traffic flows from zone A to zone B. That flow is what I refer to as a +zone-pair-direction. eg. A->B and B->A are two zone-pair-destinations. + +Ruleset are created per zone-pair-direction. + +I name rule sets to indicate which zone-pair-direction they represent. eg. +ZoneA-ZoneB or ZoneB-ZoneA. LAN-DMZ, DMZ-LAN. + +In VyOS, you have to have unique Ruleset names. In the event of overlap, I +add a "-6" to the end of v6 rulesets. eg. LAN-DMZ, LAN-DMZ-6. This allows for +each auto-completion and uniqueness. + +In this example we have 4 zones. LAN, WAN, DMZ, Local. The local zone is the +firewall itself. + +If your computer is on the LAN and you need to SSH into your VyOS box, you +would need a rule to allow it in the LAN-Local ruleset. If you want to access +a webpage from your VyOS box, you need a rule to allow it in the Local-LAN +ruleset. + +In rules, it is good to keep them named consistently. As the number of rules +you have grows, the more consistency you have, the easier your life will be. + +.. code-block:: sh + + Rule 1 - State Established, Related + Rule 2 - State Invalid + Rule 100 - ICMP + Rule 200 - Web + Rule 300 - FTP + Rule 400 - NTP + Rule 500 - SMTP + Rule 600 - DNS + Rule 700 - DHCP + Rule 800 - SSH + Rule 900 - IMAPS + +The first two rules are to deal with the idiosyncrasies of VyOS and iptables. + +Zones and Rulesets both have a default action statement. When using +Zone-Policies, the default action is set by the zone-policy statement and is +represented by rule 10000. + +It is good practice to log both accepted and denied traffic. It can save you +significant headaches when trying to troubleshoot a connectivity issue. + +To add logging to the default rule, do: + +.. code-block:: sh + + set firewall name <ruleSet> enable-default-log + + +By default, iptables does not allow traffic for established session to return, +so you must explicitly allow this. I do this by adding two rules to every +ruleset. 1 allows established and related state packets through and rule 2 +drops and logs invalid state packets. We place the established/related rule at +the top because the vast majority of traffic on a network is established and +the invalid rule to prevent invalid state packets from mistakenly being matched +against other rules. Having the most matched rule listed first reduces CPU load +in high volume environments. Note: I have filed a bug to have this added as a +default action as well. + +''It is important to note, that you do not want to add logging to the +established state rule as you will be logging both the inbound and outbound +packets for each session instead of just the initiation of the session. +Your logs will be massive in a very short period of time.'' + +In VyOS you must have the interfaces created before you can apply it to the +zone and the rulesets must be created prior to applying it to a zone-policy. + +I create/configure the interfaces first. Build out the rulesets for each +zone-pair-direction which includes at least the three state rules. Then I setup +the zone-policies. + +Zones do not allow for a default action of accept; either drop or reject. +It is important to remember this because if you apply an interface to a zone +and commit, any active connections will be dropped. Specifically, if you are +SSH’d into VyOS and add local or the interface you are connecting through to a +zone and do not have rulesets in place to allow SSH and established sessions, +you will not be able to connect. + +The following are the rules that were created for this example +(may not be complete), both in IPv4 and IPv6. If there is no IP specified, +then the source/destination address is not explicit. + +.. code-block:: sh + + WAN – DMZ:192.168.200.200 – tcp/80 + WAN – DMZ:192.168.200.200 – tcp/443 + WAN – DMZ:192.168.200.200 – tcp/25 + WAN – DMZ:192.168.200.200 – tcp/53 + WAN – DMZ:2001:0DB8:0:BBBB::200 – tcp/80 + WAN – DMZ:2001:0DB8:0:BBBB::200 – tcp/443 + WAN – DMZ:2001:0DB8:0:BBBB::200 – tcp/25 + WAN – DMZ:2001:0DB8:0:BBBB::200 – tcp/53 + + DMZ - Local - tcp/53 + DMZ - Local - tcp/123 + DMZ - Local - tcp/67,68 + + LAN - Local - tcp/53 + LAN - Local - tcp/123 + LAN - Local - tcp/67,68 + LAN:192.168.100.10 - Local - tcp/22 + LAN:2001:0DB8:0:AAAA::10 - Local - tcp/22 + + LAN - WAN - tcp/80 + LAN - WAN - tcp/443 + LAN - WAN - tcp/22 + LAN - WAN - tcp/20,21 + + DMZ - WAN - tcp/80 + DMZ - WAN - tcp/443 + DMZ - WAN - tcp/22 + DMZ - WAN - tcp/20,21 + DMZ - WAN - tcp/53 + DMZ - WAN - udp/53 + + Local - WAN - tcp/80 + Local - WAN - tcp/443 + Local - WAN - tcp/20,21 + + Local - DMZ - tcp/25 + Local - DMZ - tcp/67,68 + Local - DMZ - tcp/53 + Local - DMZ - udp/53 + + Local - LAN - tcp/67,68 + + LAN - DMZ - tcp/80 + LAN - DMZ - tcp/443 + LAN - DMZ - tcp/993 + LAN:2001:0DB8:0:AAAA::10 - DMZ:2001:0DB8:0:BBBB::200 - tcp/22 + LAN:192.168.100.10 - DMZ:192.168.200.200 - tcp/22 + +Since we have 4 zones, we need to setup the following rulesets. + +.. code-block:: sh + + Lan-wan + Lan-local + Lan-dmz + Wan-lan + Wan-local + Wan-dmz + Local-lan + Local-wan + Local-dmz + Dmz-lan + Dmz-wan + Dmz-local + +Even if the two zones will never communicate, it is a good idea to create the +zone-pair-direction rulesets and set enable-default-log. This will allow you to +log attempts to access the networks. Without it, you will never see the +connection attempts. + +This is an example of the three base rules. + +.. code-block:: sh + + name wan-lan { + default-action drop + enable-default-log + rule 1 { + action accept + state { + established enable + related enable + } + } + rule 2 { + action drop + log enable + state { + invalid enable + } + } + } + + +Here is an example of an IPv6 DMZ-WAN ruleset. + +.. code-block:: sh + + ipv6-name dmz-wan-6 { + default-action drop + enable-default-log + rule 1 { + action accept + state { + established enable + related enable + } + } + rule 2 { + action drop + log enable + state { + invalid enable + } + rule 100 { + action accept + log enable + protocol ipv6-icmp + } + rule 200 { + action accept + destination { + port 80,443 + } + log enable + protocol tcp + } + rule 300 { + action accept + destination { + port 20,21 + } + log enable + protocol tcp + } + rule 500 { + action accept + destination { + port 25 + } + log enable + protocol tcp + source { + address 2001:db8:0:BBBB::200 + } + } + rule 600 { + action accept + destination { + port 53 + } + log enable + protocol tcp_udp + source { + address 2001:db8:0:BBBB::200 + } + } + rule 800 { + action accept + destination { + port 22 + } + log enable + protocol tcp + } + } + +Once you have all of your rulesets built, then you need to create your +zone-policy. + +Start by setting the interface and default action for each zone. + +.. code-block:: sh + + set zone-policy zone dmz default-action drop + set zone-policy zone dmz interface eth0.30 + +In this case, we are setting the v6 ruleset that represents traffic sourced +from the LAN, destined for the DMZ. +Because the zone-policy firewall syntax is a little awkward, I keep it straight +by thinking of it backwards. + + set zone-policy zone dmz from lan firewall ipv6-name lan-dmz-6 + +dmz-lan policy is lan-dmz. You can get a rhythm to it when you build out a bunch at one time. + +In the end, you will end up with something like this config. I took out everything but the Firewall, Interfaces, and zone-policy sections. It is long enough as is. +== IPv6 Tunnel == + +If you are using a IPv6 tunnel from HE.net or someone else, the basis is the same except you have two WAN interface. One for v4 and one for v6. + +You would have 5 zones instead of just 4 and you would configure your v6 ruleset between your tunnel interface and your LAN/DMZ zones instead of to the WAN. + +LAN, WAN, DMZ, local and TUN (tunnel) + +v6 pairs would be: + +.. code-block:: sh + + lan-tun + lan-local + lan-dmz + tun-lan + tun-local + tun-dmz + local-lan + local-tun + local-dmz + dmz-lan + dmz-tun + dmz-local + +Notice, none go to WAN since WAN wouldn't have a v6 address on it. + +You would have to add a couple of rules on your wan-local ruleset to allow protocol 41 in. + +Something like: + +.. code-block:: sh + + rule 400 { + action accept + destination { + address 172.16.10.1 + } + log enable + protocol 41 + source { + address ip.of.tunnel.broker + } + } + |