Describe the Operation of Rip and Ospf and Discuss Mechanisms That Can Be Used to Improve the Reconvergence Time of These Interior Gateway Routing Protocols. What Are the Consequences of Least-Cost Routing in a Single-

Only available on StudyMode
  • Topic: Subnetwork, Routing, Classless Inter-Domain Routing
  • Pages : 4 (1294 words )
  • Download(s) : 154
  • Published : October 25, 2011
Open Document
Text Preview
The RIP protocol is a dynamic, distance-vector routing protocol used in local and wide area networks. This is an implementation of single routing metric (hop count) which measures the best route distance between the source and a destination network RIP. RIP is an interior gateway protocol (IGP) which means that it performs routing within a single autonomous system (AS). RFC1058 and RFC1723 are two formal documents that define this protocol. RIP uses UDP port 520 for route updates and sending messages and is normally sent as a broadcast. The fundamental operation metric is based solely on the calculations of the number of hops it takes to the destination network. For example, a router is defined to be one hop from a directly connected network; therefore the number of hops along a path from a given source to a given destination is represented as the number of networks that a datagram has encountered along that specified path. RIP has a maximum distance of 15 hops; a hop count of 16 or more is defined as infinity as it is considered unreachable by RIP, hence it is only suitable for small networks. This fact is used by RIP to prevent routing loops. The two RIP router types in which participants are divided are activate gateways and passive host. Active participants broadcast their routes to others every 30 seconds whereas passive participants listen and update their routine tables relying on other routers advertisements as they do not advertise. In terms of RIP operations, initially routers are configured with directly connected network addresses, whereby the packets are being routed by the classful routing protocol and are interpreted according to the subnet masks locally configured on the routers interfaces. Therefore all subnet masks within a major, class-level network must be consistent. RIP broadcast request retrieves RIP information on each RIP-enabled interface whereas the RIP table received is compared to its own table causing the routers to add new entries...
tracking img