Authentication configuration..

Unanswered Question
Apr 3rd, 2008

Hi all,

I'm running EIGRP key-chains and authentication from one router to another and after configuring one side i get the expected routes start to flap. But also i can still ping from one end of the link to the other. Why is that if the authentication on both sides are different? If i can still ping what's the purpose of the authentication in the first place?

I'm basically trying to ask "what's the purpose of authentication?"

The key-chains and key-strings are the same across all routers, but i didn't authenticate (that word becomes a pain to keep typing out) across all the interfaces - just on router 1.

I have this problem too.
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mattcalderon Thu, 04/03/2008 - 06:08

I think you are still able to ping because you still have some neighbors in use and the needed routes that are in your routing table may be from another neighbor advertising those routes. Do a traceroute and see if it takes the expected path.

Did you only set up authentication on 1 interface of router 1?

Ibbywannit Thu, 04/03/2008 - 07:32

Hmmm, just checking.

Yes it's configure across all interfaces except for the loopback interface and i can still ping.

here's the output:

R1#sh ip eigrp inter detai

IP-EIGRP interfaces for process 20

Xmit Queue Mean Pacing Time Multicast Pending

Interface Peers Un/Reliable SRTT Un/Reliable Flow Timer Routes

Se0/0 1 0/0 745 10/380 4088 0

Next xmit serial

Un/reliable mcasts: 0/0 Un/reliable ucasts: 6/4

Mcast exceptions: 0 CR packets: 0 ACKs suppressed: 0

Retransmissions sent: 0 Out-of-sequence rcvd: 0

Se0/1 1 0/0 20 10/380 380 0

Next xmit serial

Un/reliable mcasts: 0/0 Un/reliable ucasts: 3/3

Mcast exceptions: 0 CR packets: 0 ACKs suppressed: 0

Retransmissions sent: 1 Out-of-sequence rcvd: 0

Lo1 0 0/0 0 0/10 0 0

Next xmit serial

Un/reliable mcasts: 0/0 Un/reliable ucasts: 0/0

Mcast exceptions: 0 CR packets: 0 ACKs suppressed: 0

Retransmissions sent: 0 Out-of-sequence rcvd: 0

Fa0/0 2 0/0 444 0/10 2192 0

Next xmit serial

Un/reliable mcasts: 0/3 Un/reliable ucasts: 5/5

Mcast exceptions: 1 CR packets: 1 ACKs suppressed: 0

Xmit Queue Mean Pacing Time Multicast Pending

Interface Peers Un/Reliable SRTT Un/Reliable Flow Timer Routes

Retransmissions sent: 2 Out-of-sequence rcvd: 0

Just trying to understand what's the point if i can still send information...

mattcalderon Thu, 04/03/2008 - 07:35

can you post output of

sh ip prot

sh ip eigrp neigh

sh run | be router eigrp

Also try clearing your eigrp neighbors and see if you can then re-establish a neighbor relationship

Ibbywannit Thu, 04/03/2008 - 07:57

R1#sh run | be router eigrp

router eigrp 20

network 10.0.0.0

network 172.16.0.0

network 192.168.1.0

no auto-summary

no eigrp log-neighbor-changes

!

ip classless

no ip http server

!

!

!

line con 0

exec-timeout 0 0

logging synchronous

transport input none

line aux 0

line vty 0 4

!

no scheduler allocate

end

R1#sh ip eigrp nei

IP-EIGRP neighbors for process 20

H Address Interface Hold Uptime SRTT RTO Q Seq Type

(sec) (ms) Cnt Num

3 10.1.1.3 Fa0/0 11 00:30:05 12 200 0 17

2 172.16.12.2 Se0/1 11 00:33:18 20 2280 0 14

1 10.1.1.2 Fa0/0 11 00:33:21 877 5000 0 15

0 172.16.13.3 Se0/0 10 00:33:21 745 4470 0 15

R1#sh ip protoco

Routing Protocol is "eigrp 20"

Outgoing update filter list for all interfaces is

Incoming update filter list for all interfaces is

Default networks flagged in outgoing updates

Default networks accepted from incoming updates

EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0

EIGRP maximum hopcount 100

EIGRP maximum metric variance 1

Redistributing: eigrp 20

Automatic network summarization is not in effect

Routing for Networks:

10.0.0.0

172.16.0.0

192.168.1.0

Routing Information Sources:

Gateway Distance Last Update

(this router) 5 00:33:45

10.1.1.2 90 00:30:23

10.1.1.3 90 00:30:23

172.16.12.2 90 00:30:23

172.16.13.3 90 00:30:23

Distance: internal 90 external 170

Also after clearing the neighbors an neighborship is re-established in less than 5 seconds. Good job this is just a lab....

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