RIP and OSPF are routing protocols used to advertise about routes in a network they are used as Interior Gateway Protocols (IGP), which are configured inside an autonomous system. Protocols are set of rules and regulations, and they are used with routers to establish connection inside a network in computer networking. Autonomous System is a group of routers that uses common protocol to communicate inside the group. Both RIP and OSPF are open standard industry protocols which can also be used with non-Cisco devices like Juniper. RIP and OSPF use Hello messages to find about routes and establish neighbors.
RIP
RIP is a distance vector protocol which advertises network updates periodically; in RIP, the advertisements are sent every 30 seconds, and it too triggers updates when a change in network happens. It uses hop counts to calculate the metric value, which determines the best path to reach a network. RIP supports maximum of 15 routers, and 16th hop is considered unreachable or unsharable. So, RIP can be used efficiently in small networks only. It uses several loop prevention techniques and those increase convergence time of a RIP implemented network , which can be recognized as its main weak point. There are three versions of RIP. RIP V1 and RIP V2 are supported in IPv4 environment, and RIPng or RIP next generation is implemented with IPv6. RIP V1 advertises classfull networks and do not carry subnet information, while RIP V2 carries subnet information in a network. To prevent incorrect routing information from being propagated throughout a network, RIP uses split-horizon, route poisoning and hold down. Its Advertisement Distance is 120. By AD or administrative distance we show how believable a route can be.
OSPF
OSPF is widely used as an Interior Gateway Protocol. After gathering information from available routers it constructs a topology map of a network. OSPF communicate using areas; they form neighbor relationship with routers in the same autonomous system first. Every area must be virtually or directly attached to a backbone area which is numbered as “area 0”. OSPF maintains routing table, neighbor table, and database table. To select best path, it uses Dijkstra’s Shortest Path First (SPF) algorithm. OSPF select a DR (Designated Router) and BDR (Border Designated Router) for a network, which can simply be defined as a captain and a vice–captain of an army; they take orders from Captain or vice captain, but not from their colleagues. Every router is connected to these two main routers and communicates only with them, not with each other. When the DR goes down, BDR take its place and take the control of giving orders to other routers. This routing protocol use Advertisement Distance of 110 when advertising its networks.
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What is the difference between RIP and OSPF? · When considering with RIP, OSPF handles its own error detection and correction functions. · RIP uses auto summarization at classfull networks, and in OSPF, we use manual summarization, therefore, we don’t have to give commands for auto summarization. · While RIP using hop counts to calculate metric value, OSPF uses SPF (Shortest Path First) algorithm to select the best path. RIP uses lots of bandwidth as it sends periodic updates, but OSPF advertise only changes in a network. · Rip takes 30-60 seconds to converge, but OSPF converges immediately even in larger network. · RIP can be reached hop count of 15 routers, but OSPF can reach unlimited hop counts. Therefore, RIP can be used in smaller networks and OSPF can be used in larger networks.
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