Overview

The gated Routing Daemon

Table 1-1

Comparison of RIP and OSPF Protocols (Continued)

 

 

 

 

RIP

OSPF

 

 

 

 

Disadvantage: RIP generates

Advantage: OSPF generates less

 

more protocol traffic than OSPF,

protocol traffic than RIP,

 

because it propagates routing

because (i) Each router

 

information by periodically

transmits information only

 

transmitting the entire routing

about its links instead of the

 

table to neighbor routers.

whole routing table, and (ii)

 

 

OSPF allows you to divide an

 

 

autonomous system into areas,

 

 

each with a designated router

 

 

that exchanges inter-area

 

 

routing information with other

 

 

routers. Intra-area routing

 

 

information is isolated to a

 

 

single area.

 

 

 

 

Disadvantage: RIP is not

Advantage: OSPF works well in

 

appropriate for large networks,

large networks.

 

because RIP packet size

 

 

increases as the number of

 

 

networks increases.

 

 

 

 

gated supports the following exterior gateway protocols:

•The External Gateway Protocol (EGP) permits a node on the NSFNET backbone to exchange information with other backbone nodes about reaching a destination. You can use EGP to communicate routing information between autonomous systems. The EGP protocol will be obsoleted in a future release of HP-UX. Use BGP instead of the EGP protocol. BGP offers more flexibility and requires less bandwidth than EGP.

•The Border Gateway Protocol (BGP) is intended as a replacement for EGP. BGP uses path attributes to select routes. One of the attributes that BGP can pass is the sequence of autonomous systems that must be traversed to reach a destination. gated supports BGP Versions 2, 3, and 4, as described in RFCs 1163 and 1267.

gated also supports the Router Discovery Protocol (RDP), which is neither an interior nor an exterior gateway protocol. RDP is used to inform hosts of the existence of routers to which the hosts can send

26

Chapter 1