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Unformatted text preview: tonomous system, and exterior gateway protocols (EGPs), for routers to
communicate with routers in other autonomous systems.
The most popular IGP is the Routing Information Protocol (RIP) with OSPF being a newer
IGP that is gaining widespread use. A new and popular EGP is the Border Gateway Protocol
(BGP). In this chapter we looked at RIP and the types of messages that it exchanges. RIP
Version 2 is a recent enhancement that supports subnetting and other minor improvements.
We also described OSPF, BGP, and classless interdomain routing (CIDR), a newer technique
being deployed to reduce the size of the Internet routing tables.
There are a two other OSI routing protocols that you may encounter. Interdomain Routing
Protocol (IDRP) started out as a version of BGP modified for use with OSI addresses instead
of 1P. Intermediate System to Intermediate System Protocol (IS-IS) is the OSI standard IGP.
It is used for routing CLNP (Connectionless Network Protocol), an OSI protocol similar to
IP. IS-IS and OSPF are similar.
Dynamic routing is still a fertile area of internetworking research. The choice of which
routing protocol to use, and which routing daemon to run, is complex. [Periman 1992]
provides many of the details.
10.1 In Figure 10.9 which of the routes came to gateway from the router kpno? file:///D|/Documents%20and%20Settings/bigini/Docu.../homenet2run/tcpip/tcp-ip-illustrated/dynamic.htm (16 of 17) [12/09/2001 14.46.53] Chapter 10. Dynamic Routing Protocols 10.2 Assume a router has 30 routes to advertise using RIP, requiring one datagram with 25
routes and another with the remaining 5. What happens if once an hour the first datagram
with 25 routes is lost?
10.3The OSPF packet format has a checksum field, but the RIP packet does not. Why?
10.4 What effect does load balancing, as done by OSPF, have on a transport layer?
10.5 Read RFC 1058 for additional details on the implementation of RIP. In Figure 10.8 each
router advertises only the routes that it provides, and none of the other ro...
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This test prep was uploaded on 04/04/2014 for the course ECE EL5373 taught by Professor Guoyang during the Spring '12 term at NYU Poly.
- Spring '12