EIGRP Summarization

[inaiate87]

hi friends,

In EIGRP, is it possible to configure a summary route from an AS into an interface connected to a different AS?

Thnks in advance

[paul driver]

Hello

Eigrp summarization is defined at an interface level towards your eigrp peers

int xx
ip summary-address eigrp (as) xxxx.xxxxx

res

Paul

[inaiate87]

Hi Paul,

my doubt is if I have a scenario where a have RouterA with one interface in AS1 and another in AS2, if a define a summary for AS1 in the interface connected to AS2 will it work?

[Jan Hrnko · Accepted solution]

Hi,

I believe that it is not possible because different AS in EIGRP do not share/exchange routing information between them by default. The only way how to get such information from one AS to another is to configure redistribution.
http://www.cisco.com/c/en/us/support/docs/ip/enhanced-interior-gateway-routing-protocol-eigrp/16406-eigrp-toc.html#twoeigrpauto

As Paul correctly pointed out, the manual summarization is configured using the command: ip summary-address eigrp as-number network-address subnet-mask [admin-distance]

You see, there's the as-number parameter which defines the actual AS we want to perform summarization in, so unless the network you want to summarize is included in both AS (most likely due to AS redistribution in EIGRP) it will not work.

Best regards,
Jan

[inaiate87]

Thanks Jan

[Jan Hrnko]

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