eigrp and managed ethernet

Brian Knoll bknoll at 7ticks.com
Tue Sep 23 11:33:52 CDT 2008

The issue may be that only one direction of traffic is being impacted.  So maybe your A end is receiving all the hellos, while the Z end is not.  Therefore A still has Z as a neighbor, but Z doesn't have A as a neighbor.

Brian Knoll

-----Original Message-----
From: Philip Lavine [mailto:source_route at yahoo.com]
Sent: Tuesday, September 23, 2008 11:26 AM
To: nanog
Subject: Re: eigrp and managed ethernet

What is really bizarre is that I am down for minutes not seconds and the timers never fire. If I don't manually passive the connection eigrp will for some reason think there is a neighbor even though I am unable to source ping across the WAN.

----- Original Message ----
From: Matthew Huff <mhuff at ox.com>
To: Philip Lavine <source_route at yahoo.com>; nanog <nanog at merit.edu>
Sent: Tuesday, September 23, 2008 8:59:14 AM
Subject: RE: eigrp and managed ethernet

Correct. Eigrp neighbor connectivity has a short-cut when L2 connectivity goes down, otherwise it will use the eigrp neighbor hold-down timer. You can decrease that timer:

interface fa0/0
  ip hello-interval eigrp p x
  ip hold-time eigrp p y

where p is your eigrp as-number, and x is how often you want the hello (in seconds) and y is the max hold-down timer. Generally y is = x * 3


Matthew Huff       | One Manhattanville Rd
OTA Management LLC | Purchase, NY 10577
www.ox.com                | Phone: 914-460-4039
aim: matthewbhuff  | Fax:   914-460-4139

-----Original Message-----
From: Philip Lavine [mailto:source_route at yahoo.com]
Sent: Tuesday, September 23, 2008 11:43 AM
To: nanog
Subject: eigrp and managed ethernet

For some reason when I lose layer 3 connectivity between two managed Ethernet sites EIGRP does not bounce.Is this because the physical interface does not bounce?

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