RIP Overview
Routing Information Protocol (RIP) is a distance vector protocol used in moderate-sized autonomous systems (AS). Security devices support RIPv1 and RIPv2 (as defined by RFC 2453) and additional MD5 authentication extensions (as defined by RFC 2082).
Use RIP for dynamic routing on moderate-sized networks and to manage route information within a small, homogeneous, network such as a corporate LAN. The longest path allowed in a RIP network is 15 hops; a metric value of 16 indicates an invalid or unreachable destination. RIP supports both point-to-point networks (used with VPNs) and broadcast or multicast Ethernet networks. RIP does not support point-to-multipoint interfaces.
RIP maintains its own database of routes, including RIP protocol routes and redistributed routes. This database contains one entry for every destination that is reachable through the RIP routing instance. RIP adds the best routes to the VR routing table based on the virtual router’s ECMP limit (configured in the General Properties area of the virtual router) and the alternate route limit (configured in the virtual router’s RIP parameters). RIP sends out messages that contain the complete routing table to every neighboring router every 30 seconds. These messages are normally sent as multicasts to address 224.0.0.9 from the RIP port.
To enable RIP on a security device, you must first enable RIP on a virtual router, then enable RIP on individual interfaces. You can also configure optional RIP settings, such as the following:
- Global settings, such as timers and trusted RIP neighbors, that are set at the VR level for the RIP protocol.
- Interface settings, such as authentication, that are set on a per-interface basis for the RIP protocol. When you configure a RIP parameter at the interface level, the parameter setting affects the RIP operation only on the specific interface.
Additionally, you can set security-related RIP settings at either the VR level or on a per-interface basis.