EIGRP Part 2 (Authentication - Keychain)

Enable Authentication under the EIGRP interface:

R2(config-if)#ip authentication mode eigrp 10 md5
R2(config-if)#ip authentication key-chain eigrp 10 joel

Configure keychain # and Password:

R2(config)#key chain joel
R2(config-keychain)#key 1
R2(config-keychain-key)#key-string joel
R2(config-keychain-key)#default send-lifetime
R2(config-keychain-key)#default accept-lifetime

Verify that EIGRP authentication is being used.

R2#show ip eigrp interfaces detail fastEthernet 0/0
IP-EIGRP interfaces for process 10
                        Xmit Queue   Mean   Pacing Time   Multicast    Pending
Interface        Peers  Un/Reliable  SRTT   Un/Reliable   Flow Timer   Routes
Fa0/0              1        0/0        54       0/2           50           0
  Hello interval is 5 sec
  Next xmit serial <none>
  Un/reliable mcasts: 0/4  Un/reliable ucasts: 8/23
  Mcast exceptions: 3  CR packets: 3  ACKs suppressed: 0
  Retransmissions sent: 15  Out-of-sequence rcvd: 0
  Authentication mode is md5,  key-chain is "joel"  Use multicast
R2#
R2#show key chainKey-chain joel:
    key 1 -- text "joel"
        accept lifetime (always valid) - (always valid) [valid now]
        send lifetime (always valid) - (always valid) [valid now]
R2#