RIP Version 1 - Routing Protocols and Concepts - page 198

Figure 5-7 debug ip rip Command (Answer)

R2# debug ip rip
RIP protocol debugging is on
RIP: received v1 update from on Serial0/0/0
in 1 hops
RIP: received v1 update from on Serial0/0/1
in 1 hops
RIP: sending v1 update to via FastEthernet0/0 ( )
RIP: build update entries
network metric 1
network metric 2
subnet metric 2
subnet metric 1
RIP: sending v1 update to via Serial0/0/1 ( )
RIP: build update entries
network metric 1
RIP: sending v1 update to via Serial0/0/0 ( )
RIP: build update entries
network metric 1
network metric 2
subnet metric 1
R2# undebug all
All possible debugging has been turned off

192.168.1.66

1

192.168.1.32

172.16.0.2

2

172.17.0.0

255.255.255.255 192.168.1.97

172.16.0.0

3

172.17.0.0
192.168.1.32

192.168.1.64

255.255.255.255 172.16.0.1

4

192.168.1.0

255.255.255.255 192.168.1.65

5

172.16.0.0
172.17.0.0
192.168.1.96

Passive Interfaces

R1, R2, and R3 are currently sending out RIP updates on all interfaces—including LAN interfaces out
which there is no RIP neighbor.

Describe three ways these unnecessary updates negatively impact the LAN environment.

Bandwidth is wasted transporting unnecessary updates. Because RIP updates are broadcast,
switches will forward the updates out all ports.

■

All devices on the LAN must process the update up to the transport layers, where the receiving
device will discard the update.

■

Advertising updates on a broadcast network is a security risk. RIP updates can be intercepted
with packet-sniffing software. Routing updates can be modified and sent back to the router, cor-
rupting the routing table with false metrics that misdirect traffic .

■

What command, including the router prompt, do you use to stop unnecessary updates out an interface?
Router(config-router)# passive-interface interface

Packet Tracer Exercise 5-1 (Continued)

Packet Tracer

Activity

Open your LSG02-0501-task3.pka saved version of this Packet Tracer Exercise and complete the fol-
lowing tasks.

Task 4: Disable RIP Updates on Appropriate Interfaces

Use the debug ip rip command on any of the routers. Notice that the routers are currently
sending RIP updates out all active interfaces.

Step 1.

On R1, R2, and R3, disable RIP updates on appropriate interfaces.

Step 2.

Your completion percentage should be 100%. If not, review the previous steps to see what
part of the task you left incomplete.