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diff --git a/docs/ch06-routing.rst b/docs/ch06-routing.rst new file mode 100644 index 00000000..a14f9f4b --- /dev/null +++ b/docs/ch06-routing.rst @@ -0,0 +1,283 @@ +Routing +======= + +VyOS is a "router first" network operating system. It supports static routing, policy routing, and dynamic routing using standard protocols (RIP, OSPF, and BGP). + +Static +------ + +Static routes are manually configured network routes. + +A typical use for a static route is a static default route for systems that do not make use of DHCP or dynamic routing protocols: + +.. code-block:: sh + + set protocols static route 0.0.0.0/0 next-hop 10.1.1.1 distance '1' + +Another common use of static routes is to blackhole (drop) traffic. +In the example below, RFC 1918 private IP networks are set as blackhole routes. +This does not prevent networks within these segments from being used, since the most specific route is always used. +It does, however, prevent traffic to unknown private networks from leaving the router. Commonly refereed to as leaking. + +.. code-block:: sh + + set protocols static route 10.0.0.0/8 blackhole distance '254' + set protocols static route 172.16.0.0/12 blackhole distance '254' + set protocols static route 192.168.0.0/16 blackhole distance '254' + +Note that routes with a distance of 255 are effectively disabled and not installed into the kernel. + +RIP +--- + +Simple RIP configuration using 2 nodes and redistributing connected interfaces. + +**Node 1:** + +.. code-block:: sh + + set interfaces loopback address 10.1.1.1/32 + set protocols rip network 192.168.0.0/24 + set protocols rip redistribute connected + +**Node 2:** + +.. code-block:: sh + + set interfaces loopback address 10.2.2.2/32 + set protocols rip network 192.168.0.0/24 + set protocols rip redistribute connected + +OSPF +---- + +IPv4 +^^^^ + +A typical configuration using 2 nodes, redistribute loopback address and the node 1 sending the default route: + +**Node 1:** + +.. code-block:: sh + + set interfaces loopback lo address 10.1.1.1/32 + set protocols ospf area 0 network 192.168.0.0/24 + set protocols ospf default-information originate always + set protocols ospf default-information originate metric 10 + set protocols ospf default-information originate metric-type 2 + set protocols ospf log-adjacency-changes + set protocols ospf parameters router-id 10.1.1.1 + set protocols ospf redistribute connected metric-type 2 + set protocols ospf redistribute connected route-map CONNECT + + set policy route-map CONNECT rule 10 action permit + set policy route-map CONNECT rule 10 match interface lo + +**Node 2:** + +.. code-block:: sh + + set interfaces loopback lo address 10.2.2.2/32 + set protocols ospf area 0 network 192.168.0.0/24 + set protocols ospf log-adjacency-changes + set protocols ospf parameters router-id 10.2.2.2 + set protocols ospf redistribute connected metric-type 2 + set protocols ospf redistribute connected route-map CONNECT + + set policy route-map CONNECT rule 10 action permit + set policy route-map CONNECT rule 10 match interface lo + +IPv6 +^^^^ + +A typical configuration using 2 nodes. + +**Node 1:** + +.. code-block:: sh + + set protocols ospfv3 area 0.0.0.0 interface eth1 + set protocols ospfv3 area 0.0.0.0 range 2001:db8:1::/64 + set protocols ospfv3 parameters router-id 192.168.1.1 + set protocols ospfv3 redistribute connected + +**Node 2:** + +.. code-block:: sh + + set protocols ospfv3 area 0.0.0.0 interface eth1 + set protocols ospfv3 area 0.0.0.0 range 2001:db8:2::/64 + set protocols ospfv3 parameters router-id 192.168.2.1 + set protocols ospfv3 redistribute connected + +BGP +--- + +IPv4 +^^^^ + +A simple eBGP configuration: + +**Node 1:** + +.. code-block:: sh + + set protocols bgp 65534 neighbor 192.168.0.2 ebgp-multihop '2' + set protocols bgp 65534 neighbor 192.168.0.2 remote-as '65535' + set protocols bgp 65534 neighbor 192.168.0.2 update-source '192.168.0.1' + set protocols bgp 65534 network '172.16.0.0/16' + set protocols bgp 65534 parameters router-id '192.168.0.1' + +**Node 2:** + +.. code-block:: sh + + set protocols bgp 65535 neighbor 192.168.0.1 ebgp-multihop '2' + set protocols bgp 65535 neighbor 192.168.0.1 remote-as '65534' + set protocols bgp 65535 neighbor 192.168.0.1 update-source '192.168.0.2' + set protocols bgp 65535 network '172.17.0.0/16' + set protocols bgp 65535 parameters router-id '192.168.0.2' + + +Don't forget, the CIDR declared in the network statement MUST **exist in your routing table (dynamic or static), the best way to make sure that is true is creating a static route:** + +**Node 1:** + +.. code-block:: sh + + set protocols static route 1.0.0.0/16 blackhole distance '254' + +**Node 2:** + +.. code-block:: sh + + set protocols static route 2.0.0.0/16 blackhole distance '254' + + +IPv6 +^^^^ + +A simple BGP configuration via IPv6. + +**Node 1:** + +.. code-block:: sh + + set protocols bgp 65534 neighbor 2001:db8::2 ebgp-multihop '2' + set protocols bgp 65534 neighbor 2001:db8::2 remote-as '65535' + set protocols bgp 65534 neighbor 2001:db8::2 update-source '2001:db8::1' + set protocols bgp 65534 neighbor 2001:db8::2 address-family ipv6-unicast + set protocols bgp 65534 address-family ipv6-unicast network '2001:db8:1::/48' + set protocols bgp 65534 parameters router-id '10.1.1.1' + +**Node 2:** + +.. code-block:: sh + + set protocols bgp 65535 neighbor 2001:db8::1 ebgp-multihop '2' + set protocols bgp 65535 neighbor 2001:db8::1 remote-as '65534' + set protocols bgp 65535 neighbor 2001:db8::1 update-source '2001:db8::2' + set protocols bgp 65535 neighbor 2001:db8::1 address-family ipv6-unicast + set protocols bgp 65535 address-family ipv6-unicast network '2001:db8:2::/48' + set protocols bgp 65535 parameters router-id '10.1.1.2' + + +Don't forget, the CIDR declared in the network statement **MUST exist in your routing table (dynamic or static), the best way to make sure that is true is creating a static route:** + +**Node 1:** + +.. code-block:: sh + + set protocols static route6 2a001:100:1::/48 blackhole distance '254' + +**Node 2:** + +.. code-block:: sh + + set protocols static route6 2001:db8:2::/48 blackhole distance '254' + +Route Filter +^^^^^^^^^^^^ + +Route filter can be applied using a route-map: + +**Node1:** + +.. code-block:: sh + + set policy prefix-list AS65535-IN rule 10 action 'permit' + set policy prefix-list AS65535-IN rule 10 prefix '172.16.0.0/16' + set policy prefix-list AS65535-OUT rule 10 action 'deny' + set policy prefix-list AS65535-OUT rule 10 prefix '172.16.0.0/16' + set policy prefix-list6 AS65535-IN rule 10 action 'permit' + set policy prefix-list6 AS65535-IN rule 10 prefix '2001:db8:2::/48' + set policy prefix-list6 AS65535-OUT rule 10 action 'deny' + set policy prefix-list6 AS65535-OUT rule 10 prefix '2001:db8:2::/48' + set policy route-map AS65535-IN rule 10 action 'permit' + set policy route-map AS65535-IN rule 10 match ip address prefix-list 'AS65535-IN' + set policy route-map AS65535-IN rule 10 match ipv6 address prefix-list 'AS65535-IN' + set policy route-map AS65535-IN rule 20 action 'deny' + set policy route-map AS65535-OUT rule 10 action 'deny' + set policy route-map AS65535-OUT rule 10 match ip address prefix-list 'AS65535-OUT' + set policy route-map AS65535-OUT rule 10 match ipv6 address prefix-list 'AS65535-OUT' + set policy route-map AS65535-OUT rule 20 action 'permit' + set protocols bgp 65534 neighbor 2001:db8::2 route-map export 'AS65535-OUT' + set protocols bgp 65534 neighbor 2001:db8::2 route-map import 'AS65535-IN' + +**Node2:** + +.. code-block:: sh + + set policy prefix-list AS65534-IN rule 10 action 'permit' + set policy prefix-list AS65534-IN rule 10 prefix '172.17.0.0/16' + set policy prefix-list AS65534-OUT rule 10 action 'deny' + set policy prefix-list AS65534-OUT rule 10 prefix '172.17.0.0/16' + set policy prefix-list6 AS65534-IN rule 10 action 'permit' + set policy prefix-list6 AS65534-IN rule 10 prefix '2001:db8:1::/48' + set policy prefix-list6 AS65534-OUT rule 10 action 'deny' + set policy prefix-list6 AS65534-OUT rule 10 prefix '2001:db8:1::/48' + set policy route-map AS65534-IN rule 10 action 'permit' + set policy route-map AS65534-IN rule 10 match ip address prefix-list 'AS65534-IN' + set policy route-map AS65534-IN rule 10 match ipv6 address prefix-list 'AS65534-IN' + set policy route-map AS65534-IN rule 20 action 'deny' + set policy route-map AS65534-OUT rule 10 action 'deny' + set policy route-map AS65534-OUT rule 10 match ip address prefix-list 'AS65534-OUT' + set policy route-map AS65534-OUT rule 10 match ipv6 address prefix-list 'AS65534-OUT' + set policy route-map AS65534-OUT rule 20 action 'permit' + set protocols bgp 65535 neighbor 2001:db8::1 route-map export 'AS65534-OUT' + set protocols bgp 65535 neighbor 2001:db8::1 route-map import 'AS65534-IN' + +We could expand on this and also deny link local and multicast in the rule 20 action deny. + +Policy Routing +^^^^^^^^^^^^^^ + +VyOS supports Policy Routing, allowing traffic to be assigned to a different routing table. Traffic can be matched using standard 5-tuple matching (source address, destination address, protocol, source port, destination port). + +The following example will show how VyOS can be used to redirect web traffic to an external transparent proxy: + +.. code-block:: sh + + set policy route FILTER-WEB rule 1000 destination port 80 + set policy route FILTER-WEB rule 1000 protocol tcp + set policy route FILTER-WEB rule 1000 set table 100 + +This creates a route policy called FILTER-WEB with one rule to set the routing table for matching traffic (TCP port 80) to table ID 100 instead of the default routing table. + +To create routing table 100 and add a new default gateway to be used by traffic matching our route policy: + +.. code-block:: sh + + set protocols static table 100 route 0.0.0.0/0 next-hop 10.255.0.2 + +This can be confirmed using the show ip route table 100 operational command. + +Finally, to apply the policy route to ingress traffic on our LAN interface, we use: + +.. code-block:: sh + + set interfaces ethernet eth1 policy route FILTER-WEB + +The route policy functionality in VyOS can also be used to rewrite TCP MSS using the set policy route <name> rule <rule> set tcp-mss <value> directive, modify DSCP value using [...] set dscp <value>, or mark the traffic with an internal ID using [...] set mark <value> for further processing (e.g. QOS) on a per-rule basis for matching traffic. + +In addition to 5-tuple matching, additional options such as time-based rules, are available. See the built-in help for a complete list of options. |