3.3.n Implement and troubleshoot routing protocol authentication

eigrp uses only md5 authentication, config below:

R1(config)#key chain CHAIN (go into key chain mod and define the key)
R1(config-keychain)#key 1 (give the key a numerical value)
R1(config-keychain-key)#key-string CHAINED (define key-string)
R1(config-keychain-key)#int f0/0 (go into interface)
R1(config-if)#ip authentication mode eigrp 100 md5 (set authentication mode to md5)
R1(config-if)#ip authentication key-chain eigrp 100 CHAIN (specify the key chain made in config mode, and repeat for neighbor)
R1(config-if)#end
R1#debug eigrp packet
EIGRP Packets debugging is on
(UPDATE, REQUEST, QUERY, REPLY, HELLO, IPXSAP, PROBE, ACK, STUB, SIAQUERY, SIAREPLY)
R1#
*Mar  1 00:52:27.279: EIGRP: Sending HELLO on FastEthernet1/0
*Mar  1 00:52:27.279:   AS 100, Flags 0x0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar  1 00:52:27.363: EIGRP: received packet with MD5 authentication, key id = 1

this does not show up specifically in the blueprint but i’m adding it for completeness