Troubleshooting EIGRP Route Advertisement

This topic is to discuss the following lesson:

Hi Rene,

interface FastEthernet0/0
ip summary-address eigrp 12 5


What does the number 5 mean in the show information above ?


And what about leak-map ? when do we use it ?


R1(config-if)#ip summary-address ei 1 ?
leak-map Allow dynamic prefixes based on the leak-map


Hi Hussein,

The “5” here is the administrative distance of the summary.

The leak-map option can be used to “leak” certain prefixes from your example. You can use this to advertise a prefix that normally falls within the range of your summary.

For example, let’s say you want to advertise summary but also one specifix prefix, You can use the leak map to get “out” of the summary so that it can be advertised.


Hi Renee,

I didn’t see a topic on this. But is there a way to perform preferred route selection based on a source prefix from the local router? For example lets say I have a router that has two equal cost paths to a network. Let’s say this router has three prefixes it is advertising too. Lets say that only for one prefix will choose one explicit path and the other two prefixes will still use equal load balancing. The config should be made on the local router advertising the prefixes. Can this be done with EIGRP?

Hi Mario,

Routers normally only care about the destination, that’s it.

If you want to make routing decisions based on the source then you can use policy based routing, take a look here:

How to configure policy based routing