If a RIP environment is
properly configured, RIP routers learn all the best routes from
neighboring routers after convergence. The exact list of routes added by
RIP to the IP routing table depends, among other factors, on whether or
not the router interfaces are inside a subnetted region, whether or not
RIP v2 is being used, and whether or not host routes or default routes
are being advertised.
Problems with RIP can occur
in a mixed RIP v1 and v2 environment, with the use of Silent RIP hosts,
or when all the appropriate RIP routes are not being received and added
to the IP routing table.
Improper routes in a
mixed RIP v1 and RIP v2 environment
On networks containing
RIP v1 routers, verify that RIP v2 is configured to broadcast its
announcements on networks containing RIP v1 routers.
On networks containing
RIP v1 routers, verify that the RIP v2 router interfaces are configured
to accept both RIP v1 and RIP v2 announcements.
Silent RIP hosts are not
If there are Silent RIP
hosts on a network that are not receiving routes from the local RIP
router, verify the version of RIP supported by the Silent RIP hosts. For
example, if the Silent RIP hosts only support listening for broadcasted,
RIP v1 announcements, you cannot use RIP v2 multicasting.
If you are using the RIP
listener component available on Microsoft® Windows NT® Workstation
version 4.0, Service Pack 4 and later, you must configure your RIP
routers for RIP v1 or RIP v2 broadcasting.
RIP routers are not
receiving expected routes
- Verify that you are
not deploying variable length subnetting, disjointed subnets, or
supernetting in a RIP v1 or mixed RIP v1 and RIP v2 environment.
- If authentication is
enabled, verify that all interfaces on the same network are using
the same case-sensitive password.
- If RIP peer
filtering is being used, verify that the correct IP addresses for
the neighboring peer RIP routers are configured.
- If RIP route
filtering is being used, verify that the ranges of network IDs for
your internetwork are included or are not being excluded.
- If RIP neighbors are
configured, verify that the correct IP addresses are configured for
the unicasted RIP announcements.
- Verify that IP
packet filtering is not preventing the receiving (through input
filters) or sending (through output filters) of RIP announcements on
the router interfaces enabled for RIP. RIP traffic uses UDP port
- Verify that TCP/IP
filtering on the router interfaces is not preventing the receiving
of RIP traffic.
- For dial-up
demand-dial interfaces using auto-static updates, configure the
demand-dial interfaces to use RIP v2 multicast announcements. When a
router calls another router, each router receives an IP address from
the other router's IP address pool, which are on different subnets.
Because broadcasted RIP announcements are addressed to the subnet
broadcast address, each router does not process the other router's
broadcasted request for routes. Using multicasting, RIP requests and
announcements are processed regardless of the subnet for the router
interfaces. For more information about demand-dial interfaces and
auto-static updates, see "Demand-Dial Routing" in this book.
- For RIP over
demand-dial interfaces, verify that the packet filters on the remote
access policy profile of the answering router are not preventing the
receipt or sending of RIP traffic. TCP/IP packet filters can be
configured on the profile properties of the remote access policies
on the answering router (or the Internet Authentication Service
(IAS) server if RADIUS is used) that are used to define the traffic
that is allowed on the remote access connection.
Host or default routes
are not being propagated
- By default, host
routes and default routes are not announced using RIP. You can
change this behavior from the Advanced tab of the properties
of a RIP interface in the Routing and Remote Access snap-in.