Re: JUMBO FRAME over l2vpn connection

Hector Melo · ‎02-18-2020

hi,

Im having problems passing traffic with mtu above 1500 and df activated through l2vpn connection.

this is the configuration on both sides:

36X-PE1# sh run int vlan1617

interface Vlan1617

description PE1

mtu 1600

ip address 10.169.84.2 255.255.255.248

xconnect 172.24.0.1 1617 encapsulation mpls

36X-PE10# sh run int vlan1617

interface Vlan1617

description PE10

mtu 1600

ip address 10.169.84.5 255.255.255.248

xconnect 172.24.0.10 1617 encapsulation mpls

IOS: me360x-universalk9-mz.153-3.S1a.bin

hardward: ME-3600X-24FS-M

ping with df and mtu 1500

36XPE1#ping 10.169.84.5 df

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.169.84.5, timeout is 2 seconds:

!!!!!

with df and mtu 1501:

36XPE1#ping 10.169.84.5 df-bit size 1501

Type escape sequence to abort.

Sending 5, 1501-byte ICMP Echos to 10.169.84.5, timeout is 2 seconds:

Packet sent with the DF bit set

.....

Regars,

Carl Lindahl · ‎02-20-2020

What is the MTU of your source and destination interface? Have you checked the whole MPLS Path to confirm > 1500 MTU? I see your configuration indices 1600 MTU, but what about show interface vlan 1617 to confirm

Are you pinging another router and/or switch on the far side? Please try using something other than the two switches - I have seen a few issues where management interface on the switch is only able to do1500 mtu while your actual MPLS PW will pass the max MTU that you have configured.

Hector Melo · ‎02-26-2020

Thanks for the info,

As you said, ping with mtu about 1500 pass when you do it from another equipment. ping with the SVI where you configure the xconnect does not.

filopeter · ‎02-26-2020

Hello,

check also your ip mtu on interface Vlan1617 - "show ip interface vlan1617".

If necessary try to configure higher MTU using ip mtu command under interface vlan 1617, or try to increase the MTU in the vlan config mode

!

Switch(config)# vlan 1617
Switch(config-vlan)# mtu 1600

!

Best Regards,

P.

LinhNguyen15326 · ‎04-05-2020

I think you should check MTU configured on all node in topo,