The path with the lowest hop count to the destination is always preferred even if the longer path has a better aggregate link bandwidth and less delays. Routing decisions are based on hop counts. RIP has no concept of network delays and link costs.This is inappropriate in large environments and could cause routing inconsistencies.
RIP routers go through a period of a hold-down and garbage collection and slowly time-out information that has not been received recently.
In large networks convergence gets to be in the order of minutes. This is a major problem with large networks especially on slow links and WAN clouds.
PRO TOOLS 101 OFFICIAL COURSEWARE TRAINING MANUAL 11 FULL
Periodic broadcasts of the full routing table consume a large amount of bandwidth.Given the shortage of IP addresses and the flexibility VLSM gives in the efficient assignment of IP addresses, this is considered a major flaw. RIP cannot handle Variable Length Subnet Masks (VLSM).A RIP network that spans more than 15 hops (15 routers) is considered unreachable. RIP has certain limitations that can cause problems in large networks: The rapid growth and expansion of today's networks has pushed RIP to its limits. These chapters discuss the OSPF terminology, algorithm and the pros and cons of the protocol in designing the large and complicated networks of today. OSPF has introduced new concepts such as authentication of routing updates, Variable Length Subnet Masks (VLSM), route summarization, and so forth. The OSPF protocol is based on link-state technology, which is a departure from the Bellman-Ford vector based algorithms used in traditional Internet routing protocols such as RIP. At that time the OSPF Working Group requested that OSPF be considered for advancement to Draft Internet Standard. The discussion of the creation of a common interoperable IGP for the Internet started in 1988 and did not get formalized until 1991. OSPF protocol was developed due to a need in the internet community to introduce a high functionality non-proprietary Internal Gateway Protocol (IGP) for the TCP/IP protocol family. This paper examines how OSPF works and how it can be used to design and build large and complicated networks. The Open Shortest Path First (OSPF) protocol, defined in RFC 2328, is an Interior Gateway Protocol used to distribute routing information within a single Autonomous System.
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