EIGRP Topology Table

krjay

From the OCG:

Without learning topology data from neighbors the local topology is built from three sources

1. Prefixes of connected subnets for interfaces on which EIGRP has been enabled on that router using the network command
2. Prefixes of connected subnets for interfaces referenced in an EIGRP neighbor command
3. Prefixes learned by the redistribution of routes into EIGRP from other routing protocols
   or routing information sources

1 and 3 make sense to me. How does 2 come in to play? I can't create a static neighbor without utilizing the network command to identify the subnet the static neighbor resides on as far as I can tell. And simply enabling EIGRP and adding a static neighbor (without specifying the subnet with the network command) doesn't yield a topology table entry (or a neighbor obviously).

kohr-ah

Hi there!

It means when you add a neighbor manually.
Example: (This is taken from freeccnaworkbook)


R1>enable
R1#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#router eigrp 10
R1(config-router)#neighbor 10.80.234.2 Serial0/0
R1(config-router)#neighbor 10.80.234.3 Serial0/0
R1(config-router)#neighbor 10.80.234.4 Serial0/0
R1(config-router)#end
R1#

krjay

Yes I understand that. But in my labbing experience when I do the steps you just listed the topology table does not populate. It only populates when I enter the network command for the corresponding subnets.

joetest

krjay wrote: »

Yes I understand that. But in my labbing experience when I do the steps you just listed the topology table does not populate. It only populates when I enter the network command for the corresponding subnets.

You still need a network command for the interface you wanna form your manual neighborship on. You wanna activate EIGRP on it to form the neighborship. After that each router will advertise each owns best EIGRP routes(from IP routing table) to each other. Second statement is false. And if I remember correctly you'll see the same list in the FLG without the second statement!

james43026

I agree with joetest on this. The neighbor command doesn't enable the EIGRP routing process on any interfaces.

krjay

Thanks for the replies, I have both the FLG and OCG. I was getting quite frustrated with the FLG due to the lengthy errata. On top of that it was full of errors not listed in the errata. I don't seem to be having much better luck with the OCG

james43026

Unfortunately a lot of books in the IT industry have mistakes and or incorrect information in them. For the CCNP I've been using the OCG, and it seems decent. Although, I would have to say the INE videos for the CCNP are really good. I'm a big fan of their videos.