RE: Unicast over Eigrp neighborship

The problem is only when the 3 routers are connected on the same LAN segment. In this case if you configure the neighbor statement on two of them, the third neighbor will be lost because the first two routers stop accepting multicast hellos on that LAN interface. In your case since you have three separate segments it's not an issue.

Brian McGahan, CCIE #8593 (R&S/SP/Security)
bmcgahan_at_INE.com

Internetwork Expert, Inc.
http://www.INE.com

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of Keller Giacomarro
Sent: Friday, July 27, 2012 9:49 AM
To: ccie.butcher
Cc: Cisco certification
Subject: Re: Unicast over Eigrp neighborship

http://www.cisco.com/en/US/tech/tk365/technologies_q_and_a_item09186a008012dac4.shtml#ten

"Due to the current behavior of this command, EIGRP exchanges routing information with the neighbors in the form of unicast packets whenever the neighbor command is configured for an interface. EIGRP stops processing all multicast packets that come inbound on that interface. Also, EIGRP stops sending multicast packets on that interface."

Only the interface with the statically-configured neighbor stops processing mcast Hellos, in or out. Other interfaces would not be affected. This seems to match what you're seeing in GNS3.

-Keller

---
Sent from my phone, please pardon my fat fingers.
On Jul 27, 2012 9:39 AM, "ccie.butcher" <ccie.butcher_at_gmail.com> wrote:
>
> CCNP ROUTE, Official certification guide, Page no 45, Topic Name-  
> "Caveat when using EIGRP static neighbor". Please clarify bro.
>
>
> On Fri, Jul 27, 2012 at 8:02 PM, Keller Giacomarro <keller.g_at_gmail.com>wrote:
>
>> Where did you read that setting up a static EIGRP neighborship 
>> disables multicast Hellos on all EIGRP-enabled interfaces?
>>
>> -Keller
>>  On Jul 27, 2012 8:36 AM, "ccie.butcher" <ccie.butcher_at_gmail.com> wrote:
>>
>>>  I have three routers connected in a triangular fashion (Each router 
>>> connected with other 2 routers through serial) and eigrp is running 
>>> between three of them (Neighborship is up between the three routers).
>>>
>>> Now further, if i create static neighborship (using "neigbor" 
>>> command) between any two of the routers then would the neighborship 
>>> with the remaining 3rd router will get down automatically because 
>>> static neigborship will disable the multicast on the eigrp enabled 
>>> interfaces routers.
>>>
>>> I was doing this on GNS but neighborship between routers is still 
>>> up, please let me know what is the reason behind this, am i doing 
>>> anything wrong.
>>>
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>>>
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