Router not joining EIGRP network

Richard Tapp · ‎08-01-2013

I built 6 routers in a test lab, each one had a L3 /24 connection into a L2 VLAN on a test switch. 2 of the routers provide onward links into our company network/internet and the other 4 will be remote sites only with connections via the 2 main sites.

In the lab it was fine all 6 routers could see the full routing table. Since then I have started to ship the remote routers out to their final locations, the 1st one conencted up OK and can still see the full routing table.

The 2nd one is connected to the network OK, I can reach the internet via one of the main sites and I can connect / ping the router OK.

But it will not connect to the EIGRP process. I have checked and the EIGRP config is exactly the same as the working router, latency back to the main 2 routers is under 30msec.

In 'show ip eigrp events' I do see this message, which none of the other routers show.

i/f delayed net add: 10.x.x.x Vlan10

i/f delayed net add: 10.y.y.y GigabitEthernet0

router eigrp 10

network 10.x.x.0 0.0.15.255

I am using the same summary on all the routers, this worked in the lab and is still working on the other 3 routers that are currently connected.

Any help would be appricated.

Peter Paluch · ‎08-01-2013

Hi Richard,

A couple of questions:

From the second router, can you successfully ping the first router that runs EIGRP?
Can you post the output of the show ip eigrp neighbor and show ip protocols from the second router?
Is the connection between your two routers a Layer2 VPN or a Layer2 circuit, or is it a routed interconnection? In particular, are the first and second router on the same IP subnet?
Is the connecton between your two routers capable of carrying multicasts?

Thank you!

Best regards,

Peter

Richard Tapp · ‎08-01-2013

Thanks Peter

BTW I have now also added the L0 subnet to the routing process.

1. Yes, all routers can ping each other.

3. It is a L2 VRF/VLAN between all sites and then all 6 routers have an address in the same subnet.

2.

RT2#sh ip eigrp ne

EIGRP-IPv4 Neighbors for AS(10)

RT2#sh ip eigrp topo

EIGRP-IPv4 Topology Table for AS(10)/ID(10.x.x.x) (= L0)

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,

r - reply Status, s - sia Status

P 10.x.x.0/24, 1 successors, FD is 28160

via Connected, Vlan10

P 10.x.x.x/32, 1 successors, FD is 128256

via Connected, Loopback0

P 10.x.x.0/24, 1 successors, FD is 10002432

via Connected, GigabitEthernet0

RT2#sh ip prot

*** IP Routing is NSF aware ***

Routing Protocol is "eigrp 10"

Outgoing update filter list for all interfaces is not set

Incoming update filter list for all interfaces is not set

Default networks flagged in outgoing updates

Default networks accepted from incoming updates

EIGRP-IPv4 Protocol for AS(10)

Metric weight K1=1, K2=0, K3=1, K4=0, K5=0

NSF-aware route hold timer is 240

Router-ID: 10.x.x.x (L0)

Topology : 0 (base)

Active Timer: 3 min

Distance: internal 90 external 170

Maximum path: 4

Maximum hopcount 100

Maximum metric variance 1

Automatic Summarization: disabled

Maximum path: 4

Routing for Networks:

10.x.x.0/20

10.xx.0.0/16

Routing Information Sources:

Gateway Distance Last Update

Distance: internal 90 external 170

Richard Tapp · ‎08-01-2013

OK, could be a multicast issue. I set the primary router and this router as static neighbours and they both came up, although I did loose my other connections.

I have ask my ISP if they have set the VRF up any differently at this site.

Is there any way to check multicast between sites ?

Peter Paluch · ‎08-01-2013

Hello Richard,

Setting up the EIGRP neighbors statically was a good move. If the unicast-based sessions work then it seems to me that the multicast (or lack thereof) is the culprit here.

Testing the multicast capability of a VRF/VFI - I don't think there is a simple test for that. Some multicast groups can be permitted, some others not. I believe you should check with your SP.

Best regards,

Peter