EIGRP not forming neighbour relationships through sub-interfaces

[rlongva]

Hi,

I have 2 frame relay sub-interfaces running between 2 routers. On the 'B' end one of these sub-interfaces is in the 10.x.x.x range and runs EIGRP, the other is in the 172.x.x.x range and doesn't.

The sub-interface in the 10.x.x.x range doesn't appear to be forming neighbour relationships with it's peer router(the 'A' end).

I've done some investigation and it looks like packets sent to the 'A' end are trying to go back to the 'B' end sub-interface address that doesn't participate in EIGRP. Packets sent from the 'A' end to the 'B' end return fine.

There is no route on the 'A' end for the 172.x.x.x network so packets are being dropped.

I've pasted on the ping results and the debug ip icmp results. Could someone point me in any direction? it's doing my head in.

Thanks,

Martin

Ping from 'B' end to 'A' end

ping 10.x.x.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.x.x.1, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

Debug ip icmp on 'A' end

Jul 27 11:43:14.725 utc: ICMP: echo reply sent, src 10.x.x.1, dst 172.x.x.x

Jul 27 11:43:16.725 utc: ICMP: echo reply sent, src 10.x.x.1, dst 172.x.x.x

Jul 27 11:43:18.725 utc: ICMP: echo reply sent, src 10.x.x.1, dst 172.x.x.x

Jul 27 11:43:20.725 utc: ICMP: echo reply sent, src 10.x.x.1, dst 172.x.x.x

Jul 27 11:43:22.725 utc: ICMP: echo reply sent, src 10.x.x.1, dst 172.x.x.x

Ping from 'A' end to 'B' end

ping 10.x.x.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.x.x.2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 20/29/32 ms

[deilert]

Can you paste in a sh run from both ends along with a sh int serial x/x and sh int serial x/x.x , also a sh ip route 10.x.x.2xand sh ip route 10.x.x.1

From the debug icmp it looks like the PVC's are not on the same network the source is a 10. and the dest is a 172. , it loks like the A end thinks the source is a 172. network , are you using secondary ip addresses ?

[rlongva]

On the 'B' end

router eigrp 200

network 10.0.0.0

no auto-summary

eigrp log-neighbor-changes

sh ip route 10.x.x.1

Routing entry for 10.x.x.0/30

Known via "connected", distance 0, metric 0 (connected)

Redistributing via eigrp 200

Routing Descriptor Blocks:

* directly connected, via Serial0.1

Route metric is 0, traffic share count is 1

interface Serial0

description xxxxxxxxxxxx

no ip address

no ip directed-broadcast

ip nat outside

encapsulation frame-relay

no fair-queue

!

interface Serial0.1 point-to-point

description xxxxxxxxxxxxx

ip address 10.x.x.2 255.255.255.252

ip access-group xxxxxxxxx in

no ip directed-broadcast

ip nat outside

no cdp enable

frame-relay interface-dlci 521

!

interface Serial0.2 point-to-point

description xxxxxxxxxx

ip address 172.x.x.1 255.255.255.252

no ip directed-broadcast

ip nat outside

no arp frame-relay

no cdp enable

frame-relay interface-dlci 522

On the 'A' end

router eigrp 200

redistribute static

network 10.0.0.0

default-metric 2048 150 255 150 1500

no auto-summary

eigrp stub receive-only

eigrp log-neighbor-changes

sh ip route 10.x.x.2

Routing entry for 10.x.x.0/30

Known via "connected", distance 0, metric 0 (connected, via interface)

Redistributing via eigrp 200, ospf 1

Advertised by ospf 1 metric 1 subnets

Routing Descriptor Blocks:

* directly connected, via Serial5/2.1

Route metric is 0, traffic share count is 1

sh run int s5/2

Building configuration...

Current configuration:

!

interface Serial5/2

description xxxxxxxxxxx

no ip address

no ip directed-broadcast

encapsulation frame-relay

ip route-cache policy

no ip mroute-cache

ip policy route-map FW1

no fair-queue

frame-relay traffic-shaping

frame-relay class e1

frame-relay intf-type dce

frame-relay route 522 interface Hssi4/0 412

sh run int s5/2.1

Building configuration...

Current configuration:

!

interface Serial5/2.1 point-to-point

description xxxxxxxxxx

ip address 10.x.x.1 255.255.255.252

no ip directed-broadcast

ip policy route-map FW1

no arp frame-relay

no cdp enable

frame-relay class Core-8-to-1

frame-relay interface-dlci 521

Regards,

Martin

[deilert]

Martin

I think that your ip addresses are assingned to the wrong subinterfaces . try to assign the 10.1.1.2 ip address to s0.2 and the 172 ip to s0.1 on the B router

[Georg Pauwen]

Hello Martin,

can you post the full configurations of both routers ?

Also, have you tried an extended ping on Router B, where your source address is the 10.x.x.x address or the subinterface 0.1 ?

Regards,

GP

[rlongva]

Hi GP,

Unfortunately I can't post the full config, not allowed to.

I have tried extended pings but get the same result.

Regards,

Martin

[pmajumder]

Can you paste the output from sh ip eigrp nei detail from both ends?

[rlongva]

Sure can,

Here it is...........

'A' end

sh ip eigrp neigh det s5/2.1

IP-EIGRP neighbors for process 200

H Address Interface Hold Uptime SRTT RTO Q Seq

(sec) (ms) Cnt Num

7 10.x.x.2 Se5/2.1 11 00:00:18 0 5000 2 0

Last startup serial 32569

Version 11.2/1.0, Retrans: 4, Retries: 4, Waiting for Init, Waiting for Init Ack

UPDATE seq 2921372 ser 2-32150 Sent 18236 Init Sequenced

UPDATE seq 2921373 ser 32160-32569 Sequenced

'B' end

sh ip eigrp neigh det s0.1

IP-EIGRP neighbors for process 200

H Address Interface Hold Uptime SRTT RTO Q Seq

(sec) (ms) Cnt Num

0 10.x.x.1 Se0.1 13 00:00:21 0 5000 1 2921376

Last startup serial 4

Version 12.0/1.1, Retrans: 5, Retries: 5, Waiting for Init Ack

UPDATE seq 2 ser 3-4 Sent 21816 Init Sequenced

As you'll see they're waiting for Init Ack. I noticed this and then started running pings between the two interfaces, this is when I saw that return packets seem to be going to the 172.x.x.x address.

Regards,

Martin

[mark-obrien]

Yet another paste request. Let us see the results of "show cdp neighbor" and "show frame-relay pvc".

Mark

[rlongva]

Can't give sh cdp neigh at the moment, cdp is switched off globally on both routers, the sh frame-relay pvc for the dlci's that should connect together are located below, the router was rebooted a little while ago which is whay the uptime is so low.

Cheers,

Martin

A end

sh frame-relay pvc 521

PVC Statistics for interface Serial5/2 (Frame Relay DCE)

DLCI = 521, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial5/2.1

input pkts 10589950 output pkts 19932173 in bytes 723715877

out bytes 4142852692 dropped pkts 4591 in FECN pkts 0

in BECN pkts 0 out FECN pkts 0 out BECN pkts 0

in DE pkts 0 out DE pkts 0

out bcast pkts 1168613 out bcast bytes 81802910

Shaping adapts to BECN

pvc create time 41w6d, last time pvc status changed 00:13:24

cir 2040000 bc 256000 be 0 limit 8000 interval 32

mincir 1792000 byte increment 8000 BECN response yes

pkts 19927656 bytes 4207798113 pkts delayed 19927656 bytes delayed 4207798113

shaping active

traffic shaping drops 0

Serial5/2.1 dlci 521 is first come first serve default queueing

Output queue 0/40, 4516 drop, 88380085 dequeued

B end

sh frame-relay pvc 521

PVC Statistics for interface Serial0 (Frame Relay DTE)

DLCI = 521, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0.1

input pkts 636 output pkts 415 in bytes 36733

out bytes 28861 dropped pkts 2 in FECN pkts 0

in BECN pkts 0 out FECN pkts 0 out BECN pkts 0

in DE pkts 0 out DE pkts 0

out bcast pkts 184 out bcast bytes 11776

pvc create time 00:14:24, last time pvc status changed 00:13:44

[kli]

Try to disable split horizon on the serial interfaces on both routers and see what happen.

Ken

[rlongva]

No, no good.

Regards,

Martin

[pmajumder]

Martin - Does it work, if you use a static route on A?

Regards

Pradeep

[deilert]

Martin

I really think that the PVC's are reversed on the B router as I stated earlier. That is why you are seeing a source of 172. on the A router .