3Com 10014299 By default, the interface runs RIP-1, Define a Neighboring Router, Peer ip-address

416CHAPTER 28: CONFIGURING RIP

Defining a Neighboring RIP is a broadcast protocol. It exchanges routing information with Router non-broadcasting networks in unicast mode.

Perform the following configurations in RIP view.

Table 471 Define a Neighboring Router

Operation	Command
Define a neighboring router	peer ip-address
Cancel exchanging routing information	undo peer ip-address
with a neighboring router.

By default, no neighboring routers are defined.

Normally, this command is not recommended because the node on the other end does not need to receive two identical packets at the same time. Also when a peer sends messages, it is also subject to the restrictions of such commands as rip work, rip output, rip input and network.

Specifying RIP Version RIP-2 has two sending modes, broadcasting and multicasting, with message multicasting as the default mode. The multicast address in RIP-2 is 224.0.0.9. The advantage of multicasting is that the host not running RIP in the network does not receive RIP broadcast messages. In addition, message multicasting can also prevent the host running RIP-1 from incorrectly receiving and processing the routes with subnet mask in RIP-2.

When RIP-1 is running on the interface, the interface receives and transmits the broadcast packets of RIP-1 and RIP-2 but does not receive RIP-2 multicast messages. When RIP-2 is running on the interface, the interface can receive and transmit RIP-1 and RIP-2 broadcast packets but cannot receive RIP-2 multicast packets. When the interface runs in RIP-2 multicast mode, it receives and transmits the RIP-2 multicast packets and does not receive the RIP-1 and RIP-2 broadcast packets.

Perform the following configurations in interface view.

Table 472 Specify RIP Version

Operation	Command
Configure the interface to run RIP-1	rip version 1
Configure the interface to run RIP-2	rip version 2 [ broadcast multicast
	]
Restore the default RIP version run on the	undo rip version
interface

By default, the interface runs RIP-1.

Configuring Check Zero The check zero command is used by the router to validate the version of the RIP Field of RIP Version 1 Version 1 message. RFC 1058 stipulates that the ZERO FIELD in the RIP Version 1

header must be set to zero. If the checkzero parameter is set and the router receives a message with the zero field not 0, the router will discard the RIP message because it is the wrong version.