DMVPN + EIGRP neighbor not found

[the-lebowski]

Hello

Moving from LAB to production and I cannot get the HUB router to participate in EIGRP.  I see in the logs neighbor not found (10.1.2.192) which is the spoke's tunnel interface.

HUB:

interface Tunnel1

ip address 10.1.2.1 255.255.255.0

no ip redirects

ip mtu 1400

no ip next-hop-self eigrp 3111

no ip split-horizon eigrp 3111

ip nhrp authentication TEST

ip nhrp map multicast dynamic

ip nhrp network-id 1

ip nhrp holdtime 300

ip tcp adjust-mss 1360

tunnel source GigabitEthernet0/0

tunnel mode gre multipoint

tunnel key 123

tunnel protection ipsec profile TEST-DMVPN shared

...........

router eigrp 3111

network 10.0.0.0

eigrp router-id 10.120.0.10

............

r4-2911-HUB#show ip eigrp neighbors

EIGRP-IPv4 Neighbors for AS(3111)

........

Sep  3 23:18:21.264: EIGRP: Neighbor(10.1.2.192) not yet found

................

SPOKE:

interface Tunnel1

ip address 10.1.2.192 255.255.255.0

no ip redirects

ip mtu 1400

ip nhrp authentication TEST

ip nhrp map 10.1.2.1 205.234.20.11

ip nhrp network-id 1

ip nhrp holdtime 300

ip nhrp nhs 10.1.2.1

ip tcp adjust-mss 1360

tunnel source GigabitEthernet0/1

tunnel mode gre multipoint

tunnel key 123

tunnel protection ipsec profile TEST-DMVPN shared

.........

router eigrp 3111

network 10.0.0.0

eigrp stub connected

..........

EIGRP-IPv4 Neighbors for AS(3111)

H   Address                 Interface              Hold Uptime   SRTT   RTO  Q  Seq

                                                   (sec)         (ms)       Cnt Num

1   10.1.2.1                Tu1                      13 00:00:10    1  5000  1  0

2   10.192.11.1             Gi0/0.1                  14 00:07:05   16   100  0  39

0   10.192.2.1              Gi0/0.2                  14 00:07:06  148   888  0  36

.......

*Sep  3 23:19:18.675: Going down: Peer 10.1.2.1 total=2 stub 0, iidb-stub=0 iid-all=0

*Sep  3 23:19:18.675: EIGRP: Handle deallocation failure [1]

*Sep  3 23:19:18.675: EIGRP: Neighbor 10.1.2.1 went down on Tunnel1.

*Sep  3 23:19:22.943: EIGRP: New peer 10.1.2.1.

*Sep  3 23:19:22.943: %DUAL-5-NBRCHANGE: EIGRP-IPv4 3111: Neighbor 10.1.2.1 (Tunnel1) is up: new adjacency...

Can someone help me out?  I for the life of me cannot figure out why the spoke can peer but the HUB cannot. 

[Peter Paluch · Accepted solution]

Hello,

Usually, the spoke is configured also with the ip nhrp map multicast 205.234.20.11 on its mGRE interface. I do not see this line in your spoke's configuration - would you mind adding it?

Also, do you happen to use any neighbor command in your EIGRP configuration either on the spoke or on the hub?

Best regards,

Peter

[the-lebowski]

Thanks Paul that is exactly what it was, once that was added it was able to form. 

I don't use any neighbor commands at all. 

[peterhousen]

Hi guys, just wanted to add my solution to the problem. I had the same symptoms:EIGRP neighbor not found on a DynamicMultipoint VPN.

My setup was slightly different, because I also had defined the ip nhrp map multicast destination on the spokes:

ip nhrp map multicast x.x.x.x  

Adding the eigrp neigbour did not solve my problem.

I found that I had misconfigured ip nhrp map multicast x.x.x.x : I had used the GRE address of the hub, but that should have been the interface IP of the hub. Once I had changed that, neigbourships were formed immediately :)

[adfsdafs adsfafds]

Thanks Peter. I incorrectly mapped spoke nhrp multicast to hub DMVPN tunnel interface IP. The result is EIGRP neighbor comes up on spoke but flaps (retry limit exceeded) because Q cnt never became 0. DMVPN hub never saw spokes in EIGRP neighbor.

When dmvpn multicast come ni tunnel interface (encapsulated) rather than tunnel source, it gets discarded?

[karthik2000]

Hi John,

In my hub location i have single router with one public ip natted with local ip & i have 2 isp.

When primary isp is up dmvpn is working fine. when primary isp is down dmvpn is not coming up. i have observed tunnel are up qm_ideal. But eigrp routes are not receving on secondary link.

[nzamununu]

I was missing neighbor statement under eigrp config, adding this solved my problem as well!