R2#sh run | b key
key chain prob4
 key 1
  key-string yoyo
!
!

interface Serial1/2
 ip address 180.40.7.2 255.255.255.224
 ip rip authentication mode md5
 ip rip authentication key-chain prob4
 clockrate 64000

R2#
RACK16AS>3
[Resuming connection 3 to r3 ... ]

R3#sh run | b key
key chain Prob4
 key 1
  key-string yoyo
!
!

interface Serial1/2
 ip address 180.40.7.3 255.255.255.224
 ip rip authentication mode md5
 ip rip authentication key-chain Prob4
!