VPLS XR \ Error: MTU mismatched

[kriskrs]

Hello,

I've an VPLS between N540 XR 7.2.2 and Juniper.

On both sides MTU is 2000, but i still get mismatch and PWs are down.

ACs: 1 (1 up), VFIs: 1, PWs: 3 (0 up), PBBs: 0 (0 up), VNIs: 0 (0 up)

pw-id 551, state: down, Static MAC addresses: 0

pw-id 551, state: down, Static MAC addresses: 0

pw-id 551, state: down, Static MAC addresses: 0

Any advice it would be fine.

[M02@rt37]

Hello @kriskrs 

Please prodide us ouput of that command:

#show l2vpn xconnect detail

You confirm that  MTU value is not only set on the VPLS interfaces but also on any underlying physical interfaces, subinterfaces, and VLANs ?

[kriskrs]

Hello,

Yes, is define under bridge, on both equipments, after lot of troubleshooting to fix it, we set this.

bridge group AG_THOR_PRIVATE
bridge-domain AG_THOR_PRIVATE
mtu 2000

Is a l2vpn with autodiscovery, the command with xconnect is not helping.

You can see below one site:

[MHM Cisco World]

Forget this suggestion the control is disable in both side.

For bgp signalling I need to see all l3vpn config.

MHM

[Giuseppe Larosa]

Hello @kriskrs ,

remote MTU is reported as unknown so it looks like that one side is not sending the correct info in MP BGP autodiscovery messages or local side does not understand the MTU info received.

Hope to help

Giuseppe

[kriskrs]

Hello,

Is very strange cause we have other VPLs, but not with autodiscovery, all of them have MTU 2000 under bridge, and in the output both of them have 2000 MTU (left, right).

On the other side, in Juniper is UP, but I don't see the prefixes from Cisco, but in NCS we see from Juniper, in table, but of course communication is not working.

Incoming label: 262185, Outgoing label: 24336
Local interface: lsi.1048887, Status: Up, Encapsulation: VPLS
Description: Intf - vpls AG_THOR_PRIVATE local site 7 remote site 9
Flow Label Transmit: No, Flow Label Receive: No

I've serched for issue a command to ignore MTU

ignore-mtu-mismatch

, but seems that is not available in my XR ver 7.2, if someone knows where is hidded, thx a lot. I saw that under signaling-protocol bgp it should be the place..

Thanks all,  I will keep trying.

[MHM Cisco World]

Can you share 

Shwo l2vpn bridge-domain detail 

MHM

[kriskrs]

Hello,

Thank you, I haven't found other place to set MTU, but is leaving with 2000, is fine, and other router has 2000 as well.

The only change is that, this is with autodiscovery, in comparison with the others VPLs.

Thank

Attached is the file.

[kriskrs · Accepted solution]

Hello,

I've found the answer here it seems.

https://supportforums.cisco.com/discussion/11517026/inter-vpls

"l2vpn

autodiscovery bgp

signaling-protocol bgp

mtu mismatch ignore 

//// you need this command very very necessary as without this the PW will not become UP"

I will test.

[kriskrs]

Hello,

Solved.

ACs: 1 (1 up), VFIs: 1, PWs: 3 (3 up)

!

Neighbor x.x.x.x pw-id 551, state: up, Static MAC addresses: 0
Neighbor x.x.x.x pw-id 551, state: up, Static MAC addresses: 0
Neighbor x.x.x.x pw-id 551, state: up, Static MAC addresses: 0