Internal Gateway protocol RIP Route selection algorithm (distance vector)

RIP is a route selection protocol based on distance vectors

RIP distance refers to the number of hops, not a route, is a hop, RIP allows a hop path up to 15 routers, so 16 is equivalent to not be able to reach the

Features of RIP protocol:

1: Exchange information only with neighboring routes,

2: Exchange of information is only the information you know all

3: Update every 30s

The RIP protocol mainly uses the distance vector algorithm

：

Receive a RIP message for the neighboring router (whose address is X):

(1) Modify all items in this RIP message first: Change the address in the "Next Hop" field to X and add 1 to the value of all the "distance" fields.

(2) Repeat the following steps for each item in the modified RIP message:

If the destination network in the project is not in the routing table, add the item to the routing table.

Otherwise, if the router address given in the next hop field is the same, the received item is replaced with the item in the original routing table.

Otherwise, if the distance in the received project is less than the distance in the routing table, the update is

Otherwise, do nothing.

(3) If 3 minutes have not received an updated routing table for neighboring routers, then this neighbor router is credited as unreachable router, the distance is set to 16 (distance of 16 means unreachable).

(4) return.

Internal Gateway protocol RIP Route selection algorithm (distance vector)