RIP Server Configuration¶

To configure the RIP service, start in config-frr-rip mode and run the server vrf <vrf-name> command, where <vrf-name> is the name of a Virtual Routing and Forwarding instance or default for the default route table:

tnsr(config)# route dynamic rip
tnsr(config-frr-rip)# server vrf default
tnsr(config-rip)#

This changes into config-rip mode, which contains the following commands:

allow-ecmp:

Allow equal cost mult-path routing, where the same destination is reachable through multiple routers.

default-information originate:

Transmit default route information to RIP neighbors.

distance default <value>:

Administratively sets the default distance to the given value (1-255).

distance <prefix> distance <value> [access-list <acl-name>]:

Sets custom distance values for specific network prefixes.

prefix:: The prefix for which this distance is set.
distance <value>:: The distance value to advertise for this prefix.
access-list <acl-name>:: An optional access list used to filter this distance based on specific subnets or addresses inside the given prefix.

distribution-list interface <interface> (access-list|prefix-list) (in|out) <name>:

Applies either the given access list or prefix list to routes distributed from networks on the specified interface. This allows control over which routes will be distributed by RIP to neighbors.

interface <interface>:: The interface which is the source of routes filtered by this directive. May be * or a specific interface name.
access-list (in|out) <name>:: An access list to filter against in the specified direction.
prefix-list (in|out) <name>:: A prefix list to filter against in the specified direction.

neighbor <ip4-address>:

Defines the address of a neighboring router with which TNSR will exchange routes using RIP. When a neighbor is defined in this manner, RIP will always transmit to the neighbor even on passive interfaces.

network (interface <if-name>|prefix <prefix>):

Defines which networks will have routes distributed by RIP to neighbors. These can be specified by interface or prefix.

Note

These values are not used directly, but are used by RIP to locate active subnets which match the given interface or prefix.

interface <if-name>:

Advertise routes for networks directly connected to the given interface.

prefix <prefix>:

Advertise routes for active networks matching the given prefix.

For example, if 10.2.0.0/16 is given and 10.2.0.0/24 and 10.2.1.0/24 are both present on active interfaces, then those two prefixes will be advertised to neighbors, not 10.2.0.0/16.

offset-list <interface> (in|out) <acl-name> metric <metric>:

Modifies RIP metrics using access-lists.

interface:

The interface on which metrics will be adjusted. May be * or a specific interface name.

(in|out):

The direction in which modifications are made.

in:: Modify route metrics received from RIP neighbors.
out:: Modify route metrics advertised to RIP neighbors.

acl-name:

The name of the access list used to apply metric changes.

metric <metric>:

Metric value to apply to routes matching the access list. Value can be 0-16.

passive-interface <interface> [<ip4-address>]:

Controls whether or not RIP will transmit multicast or unicast packets on interfaces. RIP messages are always accepted in passive mode, and RIP messages are always transmitted to defined neighbors.

Warning

When the default value is set to passive, the meaning of this list is inverted. Instead of specifying passive interfaces, the list defines non-passive interfaces instead.

interface:: Interface to configure as passive. May be default or a specific interface name.
ip4-address:: A specific IP address to configure as passive on the given interface.

redistribute <route-source> [(metric <value>|route-map <name>)]:

Enables redistribution of routes from another source. Available route sources are listed in Dynamic Routing Protocol Lists.

metric <val>:: Advertise the route as having the given metric.
route-map <map>:: Apply the given route map to the redistributed route advertisements.

route prefix <ip4-prefix>:

Creates a static route in RIP for the given prefix, which is advertised to neighbors as reachable through this router.

route-map-filter interface <interface> (in|out) route-map <name>:

Apply a route-map to RIP routes. See Dynamic Routing Route Maps for more information on route maps.

interface:: The interface on which this route-map will be applied. May be default or a specific interface name.
(in|out):: The direction in which the route-map will be applied to routes.
route-map <name>:: The route-map to apply.

timers (garbage-collection|table-update|timeout) <value>:

Adjust timer values for RIP. Each timer is specified in seconds and can be set to a value from 5-2147483647.

table-update:: How often RIP will transmit a copy of its route table to neighbors. Default is 30 seconds.
timeout:: How long RIP will wait before a route is no longer considered valid after receiving an advertisement. Default is 180 seconds.
garbage-collection:: The time to wait before removing an invalid route from the routing table. Default is 120 seconds.

For example, if a neighbor stops advertising a route or loses connectivity, then advertisements for that route will no longer be received. The route will eventually reach the timeout value since it is no longer seen in advertisements. Once it reaches the timeout value without an advertisement, it is flagged as invalid. Then once it has been invalid for long enough to reach the garbage collection age, it is removed from the routing table.

The lowest amount of time a route can be in the table while invalid is timeout + garbage-collection, which by default is 180+120 or 300 seconds (5 minutes). The longest time would be that value plus the update time, in this case, 330 seconds total.

version (1|2):

The RIP version to use when communicating with RIP neighbors.

1:: RIP as described in RFC 1058. An older version of the protocol which utilizes class-based routing (e.g. Class A, Class B, etc) and does not support subnetting or authentication. RIP v1 sends updates using broadcast messages which must be processed by every node on connected segments.
2:: RIP as described in RFC 1723. An updated version of the protocol which uses classless routing (CIDR), authentication. RIP v2 sends messages using multicast, allowing only interested routers to receive the messages by joining the appropriate multicast group (224.0.0.9).