How to advertise loopback addresses?

[huangedmc]

We have 2 3750's connected through routed interfaces on a fiber run.

I was going to run a test to make sure routing works.

After issuing the following into the 3750s, they can't establish neibor status:

ip routing

router eigrp 100

network 1.1.1.1 255.255.255.255

[network 2.2.2.2 255.255.255.255 on the other]

What am I missing? When I turn on debug eigrp, I keep getting messages saying that the 3750 is ignoring HELLO's from itself. How do I advertise the loopback interfaces?

thanks.

[Edison Ortiz]

try

router eigrp 100

network 1.1.1.0

no auto-summary

in the other router

router eigrp 100

network 2.2.2.0

no auto-summary.

Please rate helpful posts.

[sundar.palaniappan]

Hi,

Do you have a network statment under EIGRP for the routed interface. EIGRP has to establish adjacency for the routes to be exchanged. Do a show ip eigrp nei and see if the neighbor is up.

HTH,

Sundar

[mheusinger · Accepted solution]

Hi,

for EIGRP being able to form a neighbor relation, you need at least one common subnet being included in EIGRP. The network statement does two things: tell the EIGRP process which interfaces/networks to include in routing updates and also, where to send hellos and "look" for neighbors. The second part seems to be missing in your config.

If the routed interface bewteen the switches have IP addresses from 10.1.1.0/24 this should look like this:

Switch1:

router eigrp 100

network 1.1.1.1 255.255.255.255

network 10.1.1.0 255.255.255.0

no auto-summary

Switch2:

router eigrp 100

network 2.2.2.2 255.255.255.255

network 10.1.1.0 255.255.255.0

no auto-summary

This should be adjusted to your IP addresses on the routed interface(s).

Hope this helps! Please rate all posts.

Regards, Martin

[huangedmc]

Thanks everyone!

Adding the network that the physical interfaces are in did it...