From: John (jgarrison1@austin.rr.com)
Date: Thu Jan 31 2008 - 05:24:34 ARST
Your half right, the mechanisim that eigrp uses to determine if a neighbor
is still alive is the neighbors hello. Every time a hello is recieved the
hold timer is reset to15 seconds, 180 for nbma. If the hold timer expires
for a neighbor then any routes through that neighbor are declared dead.
Otherwise eigrp would route to a "black hole"
Think about it!!! How does eigrp know if a neighbor is down so it can
install a route from a feasible successor????? The hold timer expires,
because eigrp hasn't recieved a hello from that neighbor, Thats how
PS the faster covergence is due ro
----- Original Message -----
From: "Gopalan Rajkumar" <gopalan.rajkumar@emirates.com>
To: "John" <jgarrison1@austin.rr.com>; <ccielab@groupstudy.com>
Sent: Wednesday, January 30, 2008 11:05 PM
Subject: RE: EIGRP hold time
Sorry for the confusion..I know that there are timers for eigrp,but that
is for neighbors not for routes.Eventhough eigrp is distance
vector(hybrid),unlike rip it don't have to holddown till the route gets
flushed out.Once the neighbor is down,it will look in the topology table
for feasible successor and add it to the routing table.That why thery
have faster convergence
Regards,
Gopalan Rajkumar
-----Original Message-----
From: John [mailto:jgarrison1@austin.rr.com]
Sent: 31 January 2008 07:14
To: Gopalan Rajkumar; ccielab@groupstudy.com
Subject: Re: EIGRP hold time
EIGRP has hold timers!!!! If there was no hold timer and a neighbor
went down how would the EIGRP process change the route, or even know
that it was lost? In other words the route would never be "flushed" and
you would have a black hole, because EIGRP would be forwarding packets
to a "non existant"
route that's never been flushed. I suggest you read some docs. Start
here
http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124cr/hi
rp_r/rte_eih.htm#wp999703
----- Original Message -----
From: "Gopalan Rajkumar" <gopalan.rajkumar@emirates.com>
To: "John" <jgarrison1@austin.rr.com>; <ccielab@groupstudy.com>
Sent: Wednesday, January 30, 2008 1:02 AM
Subject: RE: EIGRP hold time
> EIGRP don't have any holdtime..Read this.
>
> Why EIGRP doesn't need timers ?
> Maintaining a Topology Table allows a router to make sure that all its
> own metrics to destination networks are larger than its neighbours,
> thereby avoiding routing loops. EIGRP therefore does not need Hold
Down
> or Flush timers since loops are avoided anyway.
>
>
>
> Regards,
> Gopalan Rajkumar
>
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> John
> Sent: 29 January 2008 21:50
> To: ccielab@groupstudy.com
> Subject: EIGRP hold time
>
> Is there a way to show what the eigrp holdtime and hello interval are?
>
> I cant't find it in the docs
>
> JG
>
>
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