13

Routing Protocols

This chapter describes how to set up RIP and OSPF routing protocol settings for the ZyWALL. First, it provides an overview of RIP and OSPF, and, then, it introduces the RIP and OSPF screens used to configure routing protocols. See Section 5.5 on page 122 for related information on these screens.

13.1 Routing Protocols Overview

Routing protocols give the ZyWALL routing information about the network from other routers. The ZyWALL then stores this routing information in the routing table, which it uses when it makes routing decisions. In turn, the ZyWALL can also provide routing information via routing protocols to other routers.

The ZyWALL supports two standards, RIP and OSPF, for routing protocols. RIP and OSPF are compared in Table 70 on page 235, and they are discussed further in the next two sections.

Table 70 OSPF vs. RIP

 

OSPF

RIP

Network Size

Large

Small (with up to 15 routers)

 

 

 

Metric

Bandwidth, hop count, throughput, round

Hop count

 

trip time and reliability.

 

 

 

 

Convergence

Fast

Slow

 

 

 

13.1.1 RIP Overview

RIP (Routing Information Protocol, RFC 1058 and RFC 1389) allows a device to exchange routing information with other routers. RIP is a vector-space routing protocol, and, like most such protocols, it uses hop count to decide which route is the shortest. Unfortunately, it also broadcasts its routes asynchronously to the network and converges slowly. Therefore, RIP is more suitable for small networks (up to 15 routers).

In the ZyWALL, you can configure two sets of RIP settings before you can use it in an interface.

First, the Authentication field specifies how to verify that the routing information that is received is the same routing information that is sent. This is discussed in more detail in Section 13.1.2 on page 236.

Second, the ZyWALL can also redistribute routing information from non-RIP networks, specifically OSPF networks and static routes, to the RIP network. Costs might be calculated differently, however, so you use the Metric field to specify the cost in RIP terms.

 

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ZyWALL USG 1000 User’s Guide