Question

Anyone pls help.
I need a short and simple summary on Routing Information Protocol (RIP) and Open Shortest Path First (OSPF)....
thnx :)

Answer 1

RIP is a distance vector protocol. Essentially, each router speaking RIP lists the networks it knows how to reach, and advertises the "cost" to get there. When a router gets one of these RIP advertisements from another router on its network, it compares its own routing information for each network with the data in the RIP advertisement. If it doesn't know about a network being advertised, it adds a route to that network to its table, and sets the entry to point to that router that advertised it, along with the cost. If it does know about a network being advertised, it compares its own cost to reach that network with that of the advertised route, and takes whichever one is better. Over time, each router will acquire a table of all the known networks, and routing to use to get to them. The "cost" used is simply how many hops a packet must take to get to that network. If the network is one the router is directly connected to, the cost is 0. If a packet destined for a network must go through another router, the cost is 1, etc. No attempt is made to analyze which of multiple parallel routes might be superior due to bandwidth, delay, congestion, policy routing, etc.

OSPF is a link-state protocol. The various routers speaking OSPF build a topology map of the network, along with information about each link. This allows the algorithms to attempt to determine optimal routing much more effectively than RIP does, and the network should respond more quickly to links changing state. However, OSPF is a much more complicated routing protocol to implement and configure.

In a former lifetime, I implemented RIP for AppleTalk for cisco, and sat next to the guy who implemented OSPF :-)

Answer 2

@whpalmer4 thank you so much :)