Compatible Systems 5.4 manual Update Method

Chapter 2 - IP Routing & Bridging 29

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 default router see the discussion of the IP Static Route Dialog Box later in this chapter.

ϖ Note: Some routers, in particular those designed to create very large corporate backbones, may use other routing protocols such as OSPF (Open Shortest Path First). These routers can simultaneously use RIP 1 (and in some cases RIP 2) to communicate with smaller routers, or each of the smaller routers can be set to use one of these backbone routers as their default router.

>Update Method

WAN interfaces which are configured to provide “dial-on-demand” service will bring a connection up (i.e. dial the other end) when there are network packets which must be transferred over the link. Once a dial-on-demand connection is up, network traffic passing across the link causes the inactivity timer for the link to be reset, keeping the connection up.

The RIP protocol periodically sends out update information across a link. These periodic update packets will cause a WAN interface set for dial-on-demand operation to stay up indefinitely.