EIGRP AD if summary is configured on interface

Rupesh Kashyap · ‎03-04-2010

Hi,

I have router A having BGP routes for 20.80.0.0/24 & 20.40.0.0/24. I have redistributed those external routers into EIGRP. S0/0 of Router-A is connected with Router-B. ON S0/0, I have summarize network on eigrp like--

Router-A (S0/0)
ip summary-address eigrp 1 20.80.0.0 255.255.0.0 5

ip summary-address eigrp 1 20.40.0.0 255.255.0.0 5

I want to know, on router-B, eigrp AD for 20.40.0.0/16 & 20.80.0.0/16 will 90 or 170? Please help.

KARUPPUCHAMY MALAIYANDI · ‎03-04-2010

Hi,

The AD for for 20.40.0.0/16 & 20.80.0.0/16 will be 90. because when you are summarizing the network, there will be 2 summarized routes will be installed into your routing interface with next-hop as null interface.

Finally these summarized routes are going to advertise into your neighbor.So the neighbor router will think that this as a eigrp routes. so the AD will be 90.

for more information have a look into the below url

http://www.cisco.com/en/US/tech/tk365/technologies_white_paper09186a0080094cb7.shtml#summarization

Regards

Karuppu

Rupesh Kashyap · ‎03-04-2010

thanks sir.

KARUPPUCHAMY MALAIYANDI · ‎03-04-2010

Hi,

Glad to help you.if you find this post is useful, just rate it.

Regards

Karuppu