09-10-2018 10:37 AM
I am having problems resolving 6PE routes on a few routers in our test environment and I'm looking for direction on how to troubleshoot 6PE.
We have a v6 lableled-unicast route that has a next-hop set to a 6pe address. On some routers, we get cef recursion to the next-hop and on others we do not.
Here's a working router(crr01):
RP/0/RSP0/CPU0:crr01#show cef ipv6 2001:506:100:f240::192:206 detail 2001:506:100:f240::192:206/128, version 21592958, internal 0x5000001 0x0 (ptr 0x7c1ea06c) [1], 0x0 (0x0), 0x208 (0x7213e888) Updated Sep 7 20:56:16.430 Prefix Len 128, traffic index 0, precedence n/a, priority 4 BGP Attribute: id: 0x48ea, Local id: 0x4bea, Origin AS: 0, Next Hop AS: 0 gateway array (0x71cc5a78) reference count 1, flags 0x4038, source rib (7), 0 backups [1 type 1 flags 0x48441 (0x7216fcd0) ext 0x0 (0x0)] LW-LDI[type=0, refc=0, ptr=0x0, sh-ldi=0x0] gateway array update type-time 1 Sep 7 20:56:16.430 LDI Update time Sep 7 20:56:16.430 via ::ffff:96.34.224.204/128, 3 dependencies, recursive [flags 0x6000] path-idx 0 NHID 0x0 [0x7c94b050 0x0] recursion-via-/128 next hop VRF - 'default', table - 0xe0000000 next hop ::ffff:96.34.224.204/128 via ::ffff:96.34.224.204:0 next hop 96.34.8.5/32 BE5 labels imposed {24146 319008} Load distribution: 0 (refcount 1) Hash OK Interface Address 0 Y Unknown ::ffff:96.34.224.204:0
Here is a router which is not recursing correctly(brr01):
RP/0/RP1/CPU0:bbr01#show cef ipv6 2001:506:100:f240::192:206 detail 2001:506:100:f240::192:206/128, version 32473621, internal 0x5000001 0x0 (ptr 0x74d60554) [1], 0x0 (0x0), 0x208 (0x7328c118) Updated Sep 7 21:06:34.906 Prefix Len 128, traffic index 0, precedence n/a, priority 4 BGP Attribute: id: 0x6050, Local id: 0x471d, Origin AS: 0, Next Hop AS: 0 gateway array (0x72bf8ce4) reference count 1, flags 0x403a, source rib (7), 0 backups [1 type 1 flags 0x148441 (0x732be248) ext 0x0 (0x0)] LW-LDI[type=0, refc=0, ptr=0x0, sh-ldi=0x0] gateway array update type-time 3 Sep 10 17:31:17.911 LDI Update time Sep 7 21:06:34.906 via ::ffff:96.34.224.204/128, 0 dependencies, recursive, platform-non_preferred [flags 0x6000] path-idx 0 NHID 0x0 [0x0 0x0] recursion-via-/128 next hop VRF - 'default', table - 0xe0000000 unresolved labels imposed {319008} Load distribution: 0 (refcount 1)
Hash OK Interface Address 0 Y Unknown drop
Both routers have a valid cef entry with a valid label for the v4 address that corresponds to the 6PE address.
RP/0/RSP0/CPU0:crr01#show cef 96.34.224.204/32 96.34.224.204/32, version 344, internal 0x1000001 0x0 (ptr 0x771113c0) [3], 0x0 (0x71ebc9e8), 0xa28 (0x7213e180) Updated Jul 18 22:31:58.095 Prefix Len 32, traffic index 0, precedence n/a, priority 3 via 96.34.8.5/32, Bundle-Ether5, 21 dependencies, weight 0, class 0 [flags 0x0] path-idx 0 NHID 0x0 [0x7181cad8 0x0] next hop 96.34.8.5/32 local adjacency local label 24032 labels imposed {24146}
RP/0/RP1/CPU0:bbr01#show cef 96.34.224.204/32 96.34.224.204/32, version 164846, internal 0x1000001 0x0 (ptr 0x7cbb8990) [3], 0x0 (0x72def720), 0xa28 (0x7bd00208) Updated Aug 7 22:00:09.543 Prefix Len 32, traffic index 0, precedence n/a, priority 3 via 96.34.11.3/32, Bundle-Ether2, 8 dependencies, weight 0, class 0 [flags 0x0] path-idx 0 NHID 0x0 [0x7271d3f4 0x0] next hop 96.34.11.3/32 local adjacency local label 1048523 labels imposed {24016} via 96.34.8.1/32, Bundle-Ether4, 8 dependencies, weight 0, class 0 [flags 0x0] path-idx 1 NHID 0x0 [0x7271d1fc 0x0] next hop 96.34.8.1/32 local adjacency local label 1048523 labels imposed {24032}
It looks as though both hosts should have connectivity and valid control-plane entries to make this work but one system is not recursing the next-hop correctly and the other is. Are there any additional 6PE troubleshooting commands I can use?
Both systems are running IOS-XR 5.3.3 BTW.
Thanks
09-10-2018 03:27 PM
This is a problem
NHID 0x0 [0x0 0x0]
i am unsure why its unresolved, maybe we can check the following
show rib ipv6 opaques ip-nexthop show cef vrf default ipv6 unresolved detail show route (vrf?) 96.34.224.204 detail
09-10-2018 03:37 PM
Thanks @tkarnani.
Here's what you asked for:
RP/0/RP1/CPU0:bbr01x1sacc#show rib ipv6 opaques ip-nexthop RP/0/RP1/CPU0:bbr01x1sacc#show cef vrf default ipv6 unresolved detail 2001:506:100:f240::192:206/128, version 32473621, internal 0x5000001 0x0 (ptr 0x74d60554) [1], 0x0 (0x0), 0x208 (0x7328c118) Updated Sep 7 21:06:34.973 Prefix Len 128, traffic index 0, precedence n/a, priority 4 BGP Attribute: id: 0x6050, Local id: 0x471d, Origin AS: 0, Next Hop AS: 0 via ::ffff:96.34.224.204/128, 0 dependencies, recursive, platform-non_preferred [flags 0x6000] path-idx 0 NHID 0x0 [0x0 0x0] recursion-via-/128 next hop VRF - 'default', table - 0xe0000000 unresolved labels imposed {319008} 2001:506:100:f240::192:207/128, version 32473622, internal 0x5000001 0x0 (ptr 0x74d5c774) [1], 0x0 (0x0), 0x208 (0x7328cc30) Updated Sep 7 21:06:34.973 Prefix Len 128, traffic index 0, precedence n/a, priority 4 BGP Attribute: id: 0x6050, Local id: 0x471d, Origin AS: 0, Next Hop AS: 0 via ::ffff:96.34.224.205/128, 0 dependencies, recursive, platform-non_preferred [flags 0x6000] path-idx 0 NHID 0x0 [0x0 0x0] recursion-via-/128 next hop VRF - 'default', table - 0xe0000000 unresolved labels imposed {319024} RP/0/RP1/CPU0:bbr01x1sacc#show route 96.34.224.204 detail Routing entry for 96.34.224.204/32 Known via "isis default", distance 115, metric 10200, type level-1 Installed Aug 7 22:00:09.600 for 4w6d Routing Descriptor Blocks 96.34.11.3, from 94.34.192.204, via Bundle-Ether2 Route metric is 10200 Label: None Tunnel ID: None Extended communities count: 0 Path id:1 Path ref count:0 NHID:0x0(Ref:0) 96.34.8.1, from 94.34.192.204, via Bundle-Ether4 Route metric is 10200 Label: None Tunnel ID: None Extended communities count: 0 Path id:2 Path ref count:0 NHID:0x0(Ref:0) Route version is 0xb (11) No local label IP Precedence: Not Set QoS Group ID: Not Set Flow-tag: Not Set Route Priority: RIB_PRIORITY_NON_RECURSIVE_MEDIUM (7) SVD Type RIB_SVD_TYPE_LOCAL Download Priority 1, Download Version 145928969 No advertising protos.
Unsure as to why that hop is unresolved. I can mpls ping between the systems which is strange.
RP/0/RP1/CPU0:bbr01x1sacc#ping mpls ipv4 96.34.224.204/32 source 96.34.224.192 Sending 5, 100-byte MPLS Echos to 96.34.224.204/32, 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. !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/12/53 ms
Traceroute looks good as well:
RP/0/RP1/CPU0:bbr01x1sacc#traceroute mpls ipv4 96.34.224.204/32 source 96.34.224.192 Tracing MPLS Label Switched Path to 96.34.224.204/32, timeout is 2 seconds 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. 0 96.34.8.0 MRU 9202 [Labels: 24032 Exp: 0] L 1 96.34.8.1 MRU 9202 [Labels: 24146 Exp: 0] 3 ms L 2 96.34.8.5 MRU 1500 [Labels: implicit-null Exp: 0] 3 ms ! 3 96.34.9.124 3 ms
Thanks for helping me out....
09-11-2018 05:08 AM - edited 09-11-2018 05:16 AM
we should have some information in this
show rib ipv6 opaques ip-nexthop
can you provide from working node?
we expect to learn the next hop from bgp
bgp puts it in the rib in the form of
Opaque key: ::Nexthop
09-11-2018 08:14 AM
Thanks @tkarnani. Let me give you a more complete output.
Working box including your previous requests for information:
RP/0/RSP0/CPU0:crr01#show rib ipv6 opaques ip-nexthop Summary of 6PE/6VPE IP over MPLS opaque data in IPv6 RIB: Opaque key: ::ffff:96.34.224.204 Opaque key: ::ffff:96.34.224.205 RP/0/RSP0/CPU0:crr01#show cef vrf default ipv6 unresolved detail RP/0/RSP0/CPU0:crr01#show route 96.34.224.204 detail Routing entry for 96.34.224.204/32 Known via "isis default", distance 115, metric 10100, type level-1 Installed Jul 18 22:31:58.321 for 7w5d Routing Descriptor Blocks 96.34.8.5, from 94.34.192.204, via Bundle-Ether5 Route metric is 10100 Label: None Tunnel ID: None Extended communities count: 0 Path id:1 Path ref count:0 NHID:0xe(Ref:50) Route version is 0x5 (5) No local label IP Precedence: Not Set QoS Group ID: Not Set Flow-tag: Not Set Route Priority: RIB_PRIORITY_NON_RECURSIVE_MEDIUM (7) SVD Type RIB_SVD_TYPE_LOCAL Download Priority 1, Download Version 66478507 No advertising protos.
Router showing the issues:
RP/0/RP1/CPU0:bbr01#show rib ipv6 opaques ip-nexthop RP/0/RP1/CPU0:bbr01#show cef vrf default ipv6 unresolved detail 2001:506:100:f240::192:206/128, version 32473621, internal 0x5000001 0x0 (ptr 0x74d60554) [1], 0x0 (0x0), 0x208 (0x7328c118) Updated Sep 7 21:06:35.119 Prefix Len 128, traffic index 0, precedence n/a, priority 4 BGP Attribute: id: 0x6050, Local id: 0x471d, Origin AS: 0, Next Hop AS: 0 via ::ffff:96.34.224.204/128, 0 dependencies, recursive, platform-non_preferred [flags 0x6000] path-idx 0 NHID 0x0 [0x0 0x0] recursion-via-/128 next hop VRF - 'default', table - 0xe0000000 unresolved labels imposed {319008} 2001:506:100:f240::192:207/128, version 32473622, internal 0x5000001 0x0 (ptr 0x74d5c774) [1], 0x0 (0x0), 0x208 (0x7328cc30) Updated Sep 7 21:06:35.119 Prefix Len 128, traffic index 0, precedence n/a, priority 4 BGP Attribute: id: 0x6050, Local id: 0x471d, Origin AS: 0, Next Hop AS: 0 via ::ffff:96.34.224.205/128, 0 dependencies, recursive, platform-non_preferred [flags 0x6000] path-idx 0 NHID 0x0 [0x0 0x0] recursion-via-/128 next hop VRF - 'default', table - 0xe0000000 unresolved labels imposed {319024} RP/0/RP1/CPU0:bbr01#show route 96.34.224.204 detail Routing entry for 96.34.224.204/32 Known via "isis default", distance 115, metric 10200, type level-1 Installed Aug 7 22:00:09.746 for 4w6d Routing Descriptor Blocks 96.34.11.3, from 94.34.192.204, via Bundle-Ether2 Route metric is 10200 Label: None Tunnel ID: None Extended communities count: 0 Path id:1 Path ref count:0 NHID:0x0(Ref:0) 96.34.8.1, from 94.34.192.204, via Bundle-Ether4 Route metric is 10200 Label: None Tunnel ID: None Extended communities count: 0 Path id:2 Path ref count:0 NHID:0x0(Ref:0) Route version is 0xb (11) No local label IP Precedence: Not Set QoS Group ID: Not Set Flow-tag: Not Set Route Priority: RIB_PRIORITY_NON_RECURSIVE_MEDIUM (7) SVD Type RIB_SVD_TYPE_LOCAL Download Priority 1, Download Version 145928969 No advertising protos.
In our network, both devices are learning about the v4 next-hops via ISIS. Neither of the routers I'm looking at have the v4 next-hop in their v4 or v6 BGP tables. The closest thing either of them have to that /32 is the summary route which is a /23 for the MPLS range, 96.34.224.0/23.
Thanks
09-11-2018 08:27 AM
this is the issue, we are missing
Opaque key: ::ffff:96.34.224.204 Opaque key: ::ffff:96.34.224.205
for a vrf route, can we see on both working/non-working how we are learning the next hop from BGP?
show bgp vrf XXXXX ipv6 unicast
09-11-2018 08:58 AM
These routes are in the default vrf only. We do not have 6VPE traffic running over them currently. What we are trying to do is use the BGP-LU routes as label-switched next-hops for other BGP routes. The 6PE addresses are not learned via BGP and are only carried in ISIS. If we aren't learning those routes from BGP, what other attributes would be required for a router to correctly install those routes as valid 6PE entires?
Here are the current routing entries for the target 6PE address on each box.
Working router:
RP/0/RSP0/CPU0:crr01#show route 96.34.224.204 detail Routing entry for 96.34.224.204/32 Known via "isis default", distance 115, metric 10100, type level-1 Installed Jul 18 22:31:58.330 for 7w5d Routing Descriptor Blocks 96.34.8.5, from 94.34.192.204, via Bundle-Ether5 Route metric is 10100 Label: None Tunnel ID: None Extended communities count: 0 Path id:1 Path ref count:0 NHID:0xe(Ref:50) Route version is 0x5 (5) No local label IP Precedence: Not Set QoS Group ID: Not Set Flow-tag: Not Set Route Priority: RIB_PRIORITY_NON_RECURSIVE_MEDIUM (7) SVD Type RIB_SVD_TYPE_LOCAL Download Priority 1, Download Version 66478507 No advertising protos.
Non-working router:
RP/0/RP1/CPU0:bbr01#show route 96.34.224.204 detail Routing entry for 96.34.224.204/32 Known via "isis default", distance 115, metric 10200, type level-1 Installed Aug 7 22:00:09.753 for 4w6d Routing Descriptor Blocks 96.34.11.3, from 94.34.192.204, via Bundle-Ether2 Route metric is 10200 Label: None Tunnel ID: None Extended communities count: 0 Path id:1 Path ref count:0 NHID:0x0(Ref:0) 96.34.8.1, from 94.34.192.204, via Bundle-Ether4 Route metric is 10200 Label: None Tunnel ID: None Extended communities count: 0 Path id:2 Path ref count:0 NHID:0x0(Ref:0) Route version is 0xb (11) No local label IP Precedence: Not Set QoS Group ID: Not Set Flow-tag: Not Set Route Priority: RIB_PRIORITY_NON_RECURSIVE_MEDIUM (7) SVD Type RIB_SVD_TYPE_LOCAL Download Priority 1, Download Version 145928969 No advertising protos.
I highlighted the NHID from the non-working router as that seems to be un-set. Not sure if 0x0 is a valid ID, but could that be an issue? Like I said, connectivity is otherwise fine between these systems so the exact disconnect is not readily apparent.
Thank you.
09-11-2018 11:17 AM
In order for the 6PE address to work, we must learn it from BGP, it must be installed in the rib with the opaque value for it to be used by cef.
i do not know the reason why, but there seems to be some *magic* behind the scenes or restrictions that require this
09-11-2018 12:46 PM
Should it be learned as a v4 or v6 route?
09-12-2018 11:09 AM - edited 09-12-2018 05:39 PM
We need to learn it as a v6 route from bgp
show bgp ipv6 labeled-unicast v6prefix detail
show bgp ipv6 unicast v6prefix detail
hopefully we should have our v6 route with a v4 next hop, once we receive this we should populate
show rib ipv6 opaques ip-nexthop
09-18-2018 07:53 AM
@tkarnani, we have a Cisco RE looking into this for us. I will post the outcome when I hear back. Thank you for your quick responses and all of your help.
09-18-2018 10:33 PM
Hi,
Are you using RSVP TE tunnels (and no LDP) in your setup? If so, you will need to enable 'mpls ldp' *even if* you do not use LDP in your network -- just configure 'mpls ldp', apply router-id, but do not list any interfaces for LDP to run on.
We had the same issue with eXR 6.4.2 on ASR9906. We do not use LDP in our core, just RSVP-TE. 'sh mpls forward' shows no labels being created and CEF would refuse to program 6PE properly until 'mpls ldp' was added to config.
09-19-2018 07:51 AM
Thanks @James Jun. Unfortunately, we are using LDP in our network and we have labels for those endpoints.
RP/0/RP0/CPU0:bbr01#show mpls forwarding 24052 24045 96.34.224.204/32 BE2 96.34.11.3 0 24052 96.34.224.204/32 BE4 96.34.8.1 0 24053 24046 96.34.224.205/32 BE2 96.34.11.3 0 24053 96.34.224.205/32 BE4 96.34.8.1 0
I wish it was that simple and thanks for the suggestion.
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