Re: EIGRP summarization

Thanks Adam. Makes sense to me now. It is for the local router to
throw out packets in case no route exists on itself within the
specified summarization boundary. Ensures that null0 is preferred over
anything else that it could possibly receive via a routing
advertisement. Great explanation!

Marc

On Mon, Jun 6, 2011 at 6:13 AM, Adam Booth <adam.booth_at_gmail.com> wrote:
> Hi Marc,
>
> The way I understand it is that the admin distance of 5 is the default admin
> distance for the discard route to null0 which is created when you do the
> summary (you can actually change this when you define the summary, if you
> didn't want it at all, just set the value to 255). It's a low distance by
> default so another routing protocol doesn't override it. To other eigrp
> routers its just another internal route so it matches the default admin
> distance for that.
>
> Within the eigrp process, you could use the distance command for recieved
> internal eigrp routes - set the eigrp peer address and have an acl matching
> the prefixes you want to have the custom distance for (this doesn't work for
> externals though)
>
> Cheers,
> Adam
>
> On Mon, Jun 6, 2011 at 11:04 PM, marc edwards <renorider_at_gmail.com> wrote:
>>
>> Morning Experts. I have been creating summary addresses in eigrp under
>> the interface (ie ip summary address eigrp X 10.1.0.0 255.255.0.0 5).
>> Everything appears to work minus the administrative distance being set
>> to 5. The next hop router will receive the advertisement as a summary
>> but it will still show up with an AD of 90. Anyone know if it should
>> be 5 or how to make the 5 show up minus any route-maps or additional
>> configuration aside from the summarization? Thanks in advance for the
>> insight.
>>
>> Marc Edwards DCNISS
>> http://reno-ccie.blogspot.com
>>
>>
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Received on Mon Jun 06 2011 - 06:17:48 ART