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+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.
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