From: Joe Martin (jmartin@capitalpremium.net)
Date: Thu Jul 31 2003 - 13:16:02 GMT-3
Raj,
The AS number in the EIGRP summary-address command is always the AS to which
you are advertising the summary.
HTH,
Joe Martin
CCIE #12035
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
ccie2be
Sent: July 31, 2003 10:06 AM
To: Group Study; Joe Martin
Subject: Re: Eigrp summarization
Hi Joe,
Thanks for getting back to me.
It sounds like you're confirming my suspecions ie. if the ip
summary-address ... command is entered under the loopback interface, since
the loopback interface itself doesn't have any eigrp neighbors, the summary
address is NOT advertised to any neighbors.
Or, put another way, it doesn't matter where the more specific routes come
from - a local interface, an eigrp neighbor - as long as it's in the route
table, you came summarize it but it will be advertised to only eigrp
neighbors reachable through the interface under which the command is
entered. Do you agree?
You reminded me of another question I've been trying to figure out in a way
that will stay in my brain.
Let's say a router is running 2 different eigrp processes, has 2 interfaces
and the router is configured such that int 1 is included under eigrp 1 and
int 2 is included under eigrp 2.
It seems that I can never remember for sure which eigrp AS # to use with the
ip summary-address ...command - the AS# FROM which the summarized routes
were learned or the AS# INTO which the summary address is being advertised.
Do you have any thoughts about this?
Thanks alot, Raj
----- Original Message -----
From: "Joe Martin" <jmartin@capitalpremium.net>
To: "ccie2be" <ccie2be@nyc.rr.com>; "CCIE GroupStudy"
<ccielab@groupstudy.com>
Sent: Thursday, July 31, 2003 11:15 AM
Subject: RE: Eigrp summarization
> Raj,
>
> The EIGRP summary address is used on the interface on which you would like
> to advertise the summary address, but it can summarize any EIGRP routes
for
> which you have a more specific route.
>
> So let's say that your lo0 iterface is 150.50.5.5/32 and you have an EIGRP
> neighbor connected on interface e0. You want to send a summary address for
> the lo0 interface to the neighbor on e0. YOu would enter the following
> command on e0:
>
> int e0
> ip add 10.0.0.1 255.255.0.0
> ip summary-address eigrp 100 150.50.5.0 255.255.255.0 85
>
> Notice I am summarizing the lo0 network to a 24-bit mask. Also, I did not
> enter the command on the lo0 interface. I entered it on the interface to
> which I wanted to advertise the summary.
>
> Also, the 100 is the EIGRP AS number; the 85 is the AD for this summary.
> Specifying the AD is optional and will default to 5 for EIGRP summary
> addresses.
>
> HTH,
>
> Joe Martin
> CCIE #12035
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> ccie2be
> Sent: July 31, 2003 8:02 AM
> To: Group Study
> Subject: Eigrp summarization
>
>
> Hi,
>
> When the Eigrp command, ip summary-address eigrp # <a.b.c.d> <m.m.m.m>, is
> entered on most interfaces, that summary address is advertised to the
eigrp
> neighbors, but when entered under a loopback interface, it isn't
> advertised.
> Is that the way it should be or did I do (or not do) something wrong?
>
> Thanks, Raj
>
>
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