RIP version 1. Routing Protocols and Concepts – Chapter 5 Sandra Coleman, CCNA, CCAI. Objectives. Describe the functions, characteristics, and operation of the RIPv1 protocol. Configure a device for using RIPv1. Verify proper RIPv1 operation.
Routing Protocols and Concepts – Chapter 5
Sandra Coleman, CCNA, CCAI
-Oldest distance vector protocol
-A classful, Distance Vector (DV) routing protocol
-Metric = hop count
-Routes with a hop count > 15 are unreachable
-16 hops = infinity
-Updates are broadcast every 30 seconds
-Calculates metrics using the Bellman Ford algorithm
-Data portion is encapsulated into UDP segment
-Must be zero
-This is sent out on startup by each RIP enabled interface
-Requests all RIP enabled neighbors to send routing table
-Message sent to requesting router containing routing table
-Does not send subnet masks in routing updates
-A router either uses the SM configure on the local interface or applies the default subnet mask of the class
-Can’t support discontiguous networks or VLSM
-Use of 5 different IP subnets
Notice that typing
Router ? At the prompt
Will show you ALL
Available routing protocols
-Use the following commands:
-show ip route
-show ip protocols -debug ip rip
-Displays routing protocol configured on router
Be able to interpret these on a test!
Refer to the routing table below. Notice the timer SINCE the last update. How long would it take to mark 192.168.1.0 INVALID if it went down? Invalid timer is 180 seconds. Subtract the time since the last update (5 seconds) and you get the answer! You will have to do this on the test as well!
-Used to display RIP routing updates as they are happening - USE undebug all to turn off ALL debugging!
-Used to prevent a router from sending updates through an interface -
Router(config-router)#passive-interface interface-type interface-number
Router(config-router)#passive-interface fa 0/0
Three classful networks are used:
The 172.30.0.0/16 network is subnetted into three subnets:
The following devices are part of the 172.30.0.0/16 classful network address:
All interfaces on R1
S0/0/0 and Fa0/0 on R2
-To remove the RIP routing process use the following command
No router rip
-To check the configuration use the following command
Processing RIP Updates
-If a routing update and the interface it’s received on belong to the same network then The subnet mask of the interface is applied to the network in the routing update
-If a routing update and the interface it’s received on belong to a different network then The classful subnet mask of the network is applied to the network in the routing update.
RIPv1 DOES NOT send subnet mask information in its updates!
-The size of routing updates is reduced
-Single routes are used to represent multiple routes which results in faster lookup in the routing table.
-Does not support discontiguous networks
Indicates a ‘default –information originate’ command from R2
When you see routing table entries that have the same network listed with 2 different outgoing interfaces…know that these are 2 EQUAL COST PATHS.