Distance Vector Routing Protocol example-rip

1. Working Principle

? Rip is a distributed routing selection protocol based on distance vectors .? The RIP Protocol requires that each vro in the network maintain the distance record from itself to each other destination network .? In the RIP Protocol, "distance" is also called "hop count". Because every time a router passes through, the number of hops increases by 1 .? Rip agrees that a path can only include 15 routers. When the maximum value of "distance" is 16, it is equivalent to inaccessible. It can be seen that rip is only applicable to small Internet.

(1) Every 30 s, the route table that you know is advertised as a broadcast address from the interfaces of all the routers and rip processes.

(2) When a rip update package is received on an interface between the producer and the rip process, perform the following operations:

I. modify the data in the rip package, add 1 to the measurement value, and change the next hop address to the router address that sends the update package. II. compare the modified route table entries with the original route table entries. If the original route table does not exist, it is directly added to the route table. If the original route table has a route entry to a network, if the next hop is the same as the old one, refresh the route records of the network. If the next hop is different, put the metric values smaller than the old one in the routing table; if both are retained in the routing table, load balancing can be achieved. A maximum of six entries are allowed. The default value is 4.
Three key points of the RIP Protocol
? To whom? --- Only exchange information with adjacent routers .? What do I send? --- The information exchanged is all information that the current vro knows, that is, its route table. When will it be sent? --- Route information is exchanged at a fixed interval, for example, every 30 seconds.


? Convergence time ( Convergencetime ): From the change of network topology to the fact that all routers in the network know the time of this table, it is called the convergence time.? Rip The main disadvantage of the Protocol is: Long convergence time

Advantages and disadvantages of RIP Protocol
? The biggest advantage of the RIP Protocol is its simplicity and low overhead .? A problem with RIP is that when a network problem occurs, it takes a longer time to transmit this information to all the routers .? Rip limits the size of the network. The maximum distance it can use is 15 (16 indicates inaccessible ).? The route information exchanged between routers is the complete route table in the router. As the network size expands, the overhead is added. Rip timer? Route update Timer: set the interval for regular route updates (default 30 s ), Send the complete route table to the neighbor? Router failure Timer: determines the wait time for a route to become a failed route (default 180 s ), Once it becomes a failed route, an update message will be sent to all neighbors, and the notification becomes invalid.? Retention failure Timer: sets the time when route information is blocked (default 180 s ). When an update packet indicating that a route is an inaccessibility route is accepted, the router enters the inactive state and continues until a better measurement data packet is accepted or the timer expires.? Route refresh Timer: Set the interval at which the route entry becomes invalid and is deleted from the route table ( 240 s ),

? R1_1 Configuration

Step 1: Start the rip Process

R1 (config) # router rip

R1 (config-router )#

Step 2: advertise the network and add processes to the interface

R1 (config-router) # network 10.0.0.0-primary network ID

? R12001 check and Verification

(1) show IP route-view route table

(2) showipprotocol-view the number of workers of the currently executed route protocol rip.

(3) debug iprip: Debug rip.

Differences between r1_1 and r1_2- R00002 Is a classless routing protocol.- Route update for multicast (224.0.0.9) (broadcast not required)- Supported Vlsm (Send mask during update)- Manual summary is supported.- Supported MD5 Authentication or plain text Authentication

Distance Vector Routing Protocol example-rip