This blog provides troubleshooting information for common problems with Arista EVPN MPLS VPWS. It covers the following error:
- Status: CLI conflict
- Status: Admin down
- Status: Interface unavailable
- Status: No remote
- Status: Unprogrammed local connector
Most of the issues start with down state in the output of "show patch panel" like below:
RR1-PE5-wa465.11:42:56#sh patch panel
Patch Connector Status
---------------------------- ------------------------------------------------------- ------
pbVpws-PE5:e471--PE1:e1312 1: BGP VPWS custAB Pseudowire PE5:e471--PE1:e1312 Down
2: Ethernet47/1
And command - "show patch panel <name> details" shows the detailed error reason:
RR1-PE5-wa465.14:58:02#sh patch panel pbVpws-PE5:e471--PE1:e1312 detail
......
Patch: pbVpws-PE5:e471--PE1:e1312, Status: Down
Connector 1: BGP VPWS custAB Pseudowire PE5:e471--PE1:e1312
Status: Interface unavailable
Local MPLS label: 100004
EVPN VPWS type: port-based
Connector 2: Ethernet47/1
Status: Interface mode
The following error status means a local misconfiguration most likely.
- Ethernet side:
- Status: CLI conflict
- Possible reason: duplicated patch panel entries for the same ethernet interface
- Status: Admin down
- Check the interface status, to make sure is up
- Pseudowire side:
- Status: Interface unavailable
- Possible reason: make sure "no switchport" under interface
After the local configuration is corrected, check the output of "show bgp evpn route-type auto-dis next-hop 0.0.0.0". This is to check if the locally originated BGP EVPN prefixes are advertised out to BGP peers.
RR1-PE5-wa465.14:58:14#show bgp evpn route-type auto-discovery next-hop 0.0.0.0
....
AS Path Attributes: Or-ID - Originator ID, C-LST - Cluster List, LL Nexthop - Link Local Nexthop
Network Next Hop Metric LocPref Weight Path
* > RD: 100.250.250.5:100 auto-discovery 50471 0000:0000:0000:0000:0000
- - - 0 i
RR1-PE5-wa465.15:07:10#show bgp evpn route-type auto-discovery next-hop 0.0.0.0 detail
BGP routing table information for VRF default
Router identifier 100.250.250.5, local AS number 65000
BGP routing table entry for auto-discovery 50471 0000:0000:0000:0000:0000, Route Distinguisher: 100.250.250.5:100
Paths: 1 available
Local
- from - (0.0.0.0)
Origin IGP, metric -, localpref -, weight 0, valid, local, best
Extended Community: Route-Target-AS:65000:100 TunnelEncap:tunnelTypeMpls L2 Attributes: control word
MPLS label: 100004
The most important information as highlighted above is the ETID/PW ID. And compare it with the definition of PW PE5:e471--PE1:e1312
RR1-PE5-wa465.15:06:29#show bgp evpn instance vpws custAB
...
Pseudowire PE5:e471--PE1:e1312
Status: up
VPWS label: 100004
Local VPWS ID: 50471
Remote VPWS ID: 101312
After this point, you are pretty sure this end of PW is good.
But if you are seeing the error status as "No remote", the device may have an issue with remote PW.
Patch: pbVpws-PE5:e471--PE1:e1312, Status: Down
Connector 1: BGP VPWS custAB Pseudowire PE5:e471--PE1:e1312
Status: No remote
Local MPLS label: 100004
EVPN VPWS type: port-based
Connector 2: Ethernet47/1
Status: Unprogrammed local connector
Now let's check the router knows how to reach PW with VPWS ID 101312.
RR1-PE5-wa465.15:13:06#show bgp evpn route-type auto-discovery | grep 101312
RR1-PE5-wa465.15:13:10#
Clearly, the router has no EVPN AD prefix with ETID 101312, so it doesn't how to reach. The next step is to log in to the other end of PW to figure out why by following the above steps. For example, the remote PW should be from NH 100.250.250.11
PE3-lp232.22:00:03#sh bgp evpn route-type auto-discovery next-hop 100.250.250.11
...
Network Next Hop Metric LocPref Weight Path
* >Ec RD: 100.250.250.11:100 auto-discovery 101331 0000:0000:0000:0000:0000
100.250.250.11 - 100 0 i Or-ID: 100.250.250.11 C-LST: 100.250.250.6
From the above output, the PE1(100.250.250.11) sends out an AD prefix with ETID 101331, not 101311.
And sometimes, you may face traffic issues even all the PW and patch panels are UP!! That's because the BGP EVPN AD prefixes only contain the local ETID/PW id, no the expected remote one. There is no way to ensure consistency.
Reference:
No comments:
Post a Comment