EIGRP neighbor relationship

[Hasho]

Hi All

Please help me understand the effect of the below configs.

Router eigrp HASHO

 address-family ipv4 vrf hasho unicast autonomous-system 100

  network 0.0.0.0 

We all know that EIGRP hello packets are multicast  to IP 224.0.0.10 for neighbor formation. Now having specified unicast in my af configs, will i still be able to form a neighbor relationship? Given the fact that hello packets are protocol independent, are these packets generated from the EIGRP PDM or from the interface? Thanks in advance!!

[Jaderson Pessoa]

it still form neighborship trough multicast address 224.0.10. You are using named eigrp trough vrf, because of it there are some difference in configuration. In your case you will need entry in interface under named eigrp configuration and apply no shut.

Look explantion below:

R1(config-router)#address-family ipv4 unicast autonomous-system 1
With this named mode, only a single instance of EIGRP needs to be created. It can be used for all
address family types. It also supports multiple VRFs limited only by available system resources.
One thing to be aware of in regards to the named mode is that configuration of the address-family
does not enable IPv4 routing as a traditional configuration of IPv4 EIGRP. A 'no shut' is required in
order to start the process.

check it: https://www.cisco.com/c/en/us/support/docs/ip/enhanced-interior-gateway-routing-protocol-eigrp/200156-Configure-EIGRP-Named-Mode.pdf

[Deepak Kumar]

Hi,

As the network command is enabling EIGRP on a particular interface that will match a configured IP subnet of interfaces. As you configured 0.0.0.0 means all Ipv4 IPs are coming under this subnet so the eigrp is enabled on all interfaces of the router.

But as you are using NAME based EIGRP so there is a sperate requirement to configure the "NO Shut" command and it is also required.