mpls ping returns QQQQQ, though ldp neighborship is established

[aswetha]

Hi Team,

ASR9k is connected to a Nokia router. IGP neighborship is Up, ldp is up. Regular ping also works but Mpls ping doesn't work.

RP/0/RP1/CPU0:KV-ASR9912-AGG2#ping 10.100.235.67 so lo0
Mon Apr 27 13:54:49.735 UTC
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.100.235.67, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms
RP/0/RP1/CPU0:KV-ASR9912-AGG2#ping mpls ipv4 10.100.235.67/32 fec-type ldp source 10.71.241.223
Mon Apr 27 13:54:58.907 UTC

Sending 5, 100-byte MPLS Echos to 10.100.235.67/32,
timeout is 2 seconds, send interval is 0 msec:

Codes: '!' - success, 'Q' - request not sent, '.' - timeout,
'L' - labeled output interface, 'B' - unlabeled output interface,
'D' - DS Map mismatch, 'F' - no FEC mapping, 'f' - FEC mismatch,
'M' - malformed request, 'm' - unsupported tlvs, 'N' - no rx label,
'P' - no rx intf label prot, 'p' - premature termination of LSP,
'R' - transit router, 'I' - unknown upstream index,
'X' - unknown return code, 'x' - return code 0

Type escape sequence to abort.

QQQQQ
Success rate is 0 percent (0/5)

RP/0/RP1/CPU0:KV-ASR9912-AGG2#sh route ipv4 10.100.235.67/32
Mon Apr 27 13:56:58.613 UTC

Routing entry for 10.100.235.67/32
Known via "ospf CORE", distance 110, metric 100, labeled SR, type intra area
Installed Apr 27 12:01:46.087 for 01:55:13
Routing Descriptor Blocks
10.198.97.89, from 10.100.235.67, via GigabitEthernet0/2/0/36, Protected
Route metric is 100
10.198.97.67, from 10.100.235.67, via TenGigE0/2/0/1.11, Backup (TI-LFA)
Repair Node(s): 10.100.235.66
Route metric is 120
No advertising protos.

RP/0/RP1/CPU0:KV-ASR9912-AGG2#sh mpls forwarding | i 10.100.235.67/32
Mon Apr 27 13:57:39.708 UTC
32784 524287 10.100.235.67/32 Gi0/2/0/36 10.198.97.89 17851919
32774 10.100.235.67/32 Te0/2/0/1.11 10.198.97.67 0 (!)

RP/0/RP1/CPU0:KV-ASR9912-AGG2#sh cef 10.100.235.67/32
Mon Apr 27 13:58:49.621 UTC
10.100.235.67/32, version 1433563, labeled SR, internal 0x1000001 0x85 (ptr 0x787c9378) [1], 0x0 (0x7877e758), 0xa28 (0x797f86f0)
Updated Apr 27 12:01:46.105
remote adjacency to GigabitEthernet0/2/0/36
Prefix Len 32, traffic index 0, precedence n/a, priority 15
Extensions: context-label:18902
via 10.198.97.89/32, GigabitEthernet0/2/0/36, 12 dependencies, weight 0, class 0, protected [flags 0x400]
path-idx 0 bkup-idx 1 NHID 0x0 [0x79627bd0 0x0]
next hop 10.198.97.89/32
local label 32784 labels imposed {524287}
via 10.198.97.67/32, TenGigE0/2/0/1.11, 29 dependencies, weight 0, class 0, backup [flags 0x300]
path-idx 1 NHID 0x0 [0x79517410 0x0]
next hop 10.198.97.67/32
remote adjacency
local label 32784 labels imposed {32774 18902}

RP/0/RP1/CPU0:KV-ASR9912-AGG2#sh mpls ldp bindings 10.100.235.67/32
Mon Apr 27 14:00:38.467 UTC
10.100.235.67/32, rev 250
Local binding: label: 32784
Remote bindings: (4 peers)
Peer Label
----------------- ---------
10.198.85.3:0 69
10.101.92.4:0 524155
10.100.235.67:0 524287
10.71.241.222:0 32775

[loris.marcellini]

Hey there, as I understand the Nokia router is directly connected to the ASR hence its next-hop to the actual destination, is that right? Nothing obvious I can see from the config, can you share the network topology or at least attempt to describe it? Also, I know this ping should work full stop, but I am curious what sort of services run on top of your MPLS core (VPN etc..)?

[aswetha]

The Topology is a square topology
Agg1 (ASR9k-1)---->Nokia Agg1
| |                                   |
| |                                   |
Agg2 (ASR9k-2)---->Nokia Agg2

Mpls pings works from cisco Agg1 to all other routers. But on cisco Agg2 problem is only with mpls ping towards Nokia Agg2
Mobile services (VPN) are terminated on cisco Aggs ASR9ks and the next hop is Nokia connected Agg. So checking mpls ping to Nokia Agg. 

[Harold Ritter]

Have you enabled MPLS oam?

mpls oam

Regards,

[aswetha]

Hi Harold,

Yes mpls oam is configured.

[Harold Ritter]

The output you provided says SR is used between the 2 devices. Are you running both SR and LDP between these devices?

Routing entry for 10.100.235.67/32
Known via "ospf CORE", distance 110, metric 100, labeled SR, type intra area

Can you do a "deb mpls oam error" and try the ping mpls again.

Regards,

[Ashish Panda]

If Label switched path is through segment routing try “fec-type generic” keyword

Regards
Ashish

[aswetha]

fec-type generic gives "unsupported tlvs"

RP/0/RP1/CPU0:KV-ASR9912-AGG2#ping mpls ipv4 10.100.235.67/32 fec-type generic source 10.71.241.223
Tue Apr 28 08:51:25.369 UTC

Sending 5, 100-byte MPLS Echos to 10.100.235.67/32,
timeout is 2 seconds, send interval is 0 msec:

Codes: '!' - success, 'Q' - request not sent, '.' - timeout,
'L' - labeled output interface, 'B' - unlabeled output interface,
'D' - DS Map mismatch, 'F' - no FEC mapping, 'f' - FEC mismatch,
'M' - malformed request, 'm' - unsupported tlvs, 'N' - no rx label,
'P' - no rx intf label prot, 'p' - premature termination of LSP,
'R' - transit router, 'I' - unknown upstream index,
'X' - unknown return code, 'x' - return code 0

Type escape sequence to abort.

mmmmm
Success rate is 0 percent (0/5)

[aswetha]

Yes Harold,

We are using both SR and ldp between these two devices.

I did a debug the output is as below.

Type escape sequence to abort.

QQRP/0/RP1/CPU0:Apr 28 08:53:32.791 UTC: lspv_server[1132]: [3870582592] ERR-Pkt: : Consistency check failed for LDP (routes in FIB 2, routes in CP 1)
QQQ
Success rate is 0 percent (0/5)
RP/0/RP1/CPU0:Apr 28 08:53:32.792 UTC: lspv_server[1132]: [3870582592] ERR-Pkt: : Consistency check failed for IP Services
RP/0/RP1/CPU0:Apr 28 08:53:32.792 UTC: lspv_server[1132]: [3870582592] ERR-Pkt: : Failed to get label stack, phy out intf and nexthop for IP FEC
RP/0/RP1/CPU0:KV-ASR9912-AGG2#RP/0/RP1/CPU0:Apr 28 08:53:32.793 UTC: lspv_server[1132]: [3870582592] ERR-Pkt: : Consistency check failed for LDP (routes in FIB 2, routes in CP 1)
RP/0/RP1/CPU0:Apr 28 08:53:32.793 UTC: lspv_server[1132]: [3870582592] ERR-Pkt: : Consistency check failed for IP Services
RP/0/RP1/CPU0:Apr 28 08:53:32.793 UTC: lspv_server[1132]: [3870582592] ERR-Pkt: : Failed to get label stack, phy out intf and nexthop for IP FEC
RP/0/RP1/CPU0:Apr 28 08:53:32.794 UTC: lspv_server[1132]: [3870582592] ERR-Pkt: : Consistency check failed for LDP (routes in FIB 2, routes in CP 1)
RP/0/RP1/CPU0:Apr 28 08:53:32.794 UTC: lspv_server[1132]: [3870582592] ERR-Pkt: : Consistency check failed for IP Services
RP/0/RP1/CPU0:Apr 28 08:53:32.794 UTC: lspv_server[1132]: [3870582592] ERR-Pkt: : Failed to get label stack, phy out intf and nexthop for IP FEC

Attaching the running-config for reference. Hope it helps

[aswetha]

Any idea Harold what the error 'Consistency check failed for LDP (routes in FIB 2, routes in CP 1)' means? 

I couldn't find much about this error.

Help is greatly appreciated.

[Harold Ritter]

I am not sure why mpls oam sees the 2 entries in the FIB, but only 1 in the RIB. This might be a bug related to mpls oam vs TI-LFA. Do you see the same issue between Agg1 (ASR9k-1) and Nokia Agg1?

By the way, do you have LDP session up and running between ASR9k-1 and ASK9k-2?

Regards,

[aswetha]

Hi Harold,

Yes the LDP is up between Agg-1 and Agg-2

And I do not see the issue between cisco Agg-1 to Nokia Agg-1

[Harold Ritter]

Could you please provide a "show route ipv4 <Nokia Agg1 loopback address>/32" and "show cef <Nokia Agg1 loopback address>/32" from ASR9k-1.

Regards,

[bsn1980in]

Hi Harold

Thanks for your feedback on this case so far.  I was helpful.  Just checking, if you found some answer to your query or have some update on this topic.

Regards/Bharat

[bsn1980in]

Hi

Have you got solution to this?  I am having similar issue.

Regards/Bharat