RIP Security

R2(config)# router rip

R2(config-router)# passive-interface default

R2(config-router)# no passive-interface s 2/0

R2(config)# key chain RIP_KEY

R2(config-keychain)# key1

R2(config-keychain-key)# key-string cisco

R2(config)# int s 2/0

R2(config-if)#ip rip authentication mode m5

R2(config-if)#ip rip authentication key-chain RIP_KEY