Compatible Systems 5.4 manual Routing Protocol

34 Chapter 2 - IP Routing & Bridging

>Routing Protocol

Routers exchange information about the most effective path for packet transfer between various end points. There are a number of different protocols which have been defined to facilitate the exchange of this information.

Routing Information Protocol (RIP) 1 is the most widely used routing protocol on IP networks. All gateways and routers that support RIP 1 period- ically broadcast routing information packets. These RIP 1 packets contain information concerning the networks that the routers and gateways can reach as well as the number of routers/gateways that a packet must travel through to reach the receiving address.

RIP 2 is an enhancement of RIP 1 which allows IP subnet information to be shared among routers, and provides for authentication of routing updates. When this protocol is chosen, the router will use the multicast address 224.0.0.9 to send and/or receive RIP 2 packets for this network interface. As with RIP 1, the router’s routing table will be periodically updated with infor- mation received in these packets.

RIP 2 is more useful in a variety of environments and allows the use of vari- able subnet masks on your network. It is also necessary for implementation of “classless” addressing as accomplished with CIDR (Classless Inter Domain Routing).

It is recommended that RIP 2 be used on any segment where all routers can use the same IP routing protocol. If one or more routers on a segment must use RIP 1, then all other routers on that segment should also be set to use RIP 1.

•If RIP 2 is selected with this pull-down menu, the router will send and/or accept RIP 2 packets over this interface, and will then periodically update its routing table with the information provided from these packets. On a large network, an up-to-date routing table will enhance network perfor- mance since the router will always be aware of the optimal path to use when sending packets.

•If RIP 1 is selected with this pull-down menu, the router will send and/or accept RIP 1 packets, and will then periodically update its routing table with the information provided from these packets.

•If None is selected with this pull-down menu, the router will not be able to update its routing table and will always direct traffic for addresses it does not have a route for (addresses not on one of the networks connected to its interfaces) to the “default router” defined in its IP Static Route Dialog Box. It will then be the responsibility of the default router to direct the packets to the correct address. For information on setting the