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New Member

Enabling Jumbo Frames on N7K VPC Peer Link


I have a 2 Nexus 5k's in a VPC environment. These 2 N5K's connect to the 2 upstream Catalyst 6500. Right now the the port-channels connecting from Nexus 5K's to Catalyst 6500 are enabled with jumbo frames(mtu 9216). As a part of migration work, i am migrating the uplinks from  Catalyst 6500 to Nexus 7000.So my new uplinks from Nexus 5000 will be connecting to Nexus 7000.When i migrate the uplinks to Nexus 7000, i will enable the jumbo frames on the VPC port-channel between Nexus 5000 to Nexus 7000. But my question here is: do i need to enable the jumbo frames(mtu 9216) on the peer link between Nexus 7k also. Please let me know if anyone has gone thruough this issue.

I have attached the diagram of my topology after i migrate to Nexus 7k.


   If you are going support

   If you are going support jumbo frames throughout your N7k's then yes I would enable it on the peer links.

Hello.Per my understanding,


Per my understanding, jumbo frames are enabled on peer-link by default.

New Member

But when i do.... "sh run int

But when i do.... "sh run int po1 all"  i don't see mtu 9216 config over there. In my case, Port-channel 1 is a peer links between Nexus 7K. Could you please let me know how can i verify jumbo frames has been enabled on the peer link.

New Member

Saroj, I believe that mtu



I believe that mtu 9216 is on the VPC peer-link by default. I attempted to configure it in our lab and received an error when trying to apply it to the port-channel. I then did a show interface and noticed that the MTU was already at 9216.


interface port-channel10
  switchport mode trunk
  switchport trunk allowed vlan 1,810-813,820-823,900
  spanning-tree port type network
  vpc peer-link

N9k-1(config-if)# int p10
N9k-1(config-if)# mtu ?
  <1500-9216>  Enter MTU
N9k-1(config-if)# mtu 9216
ERROR: port-channel10: Cannot configure port MTU on Peer-Link.


N9k-1(config-if)# sho int p10
port-channel10 is up
admin state is up,
  Hardware: Port-Channel, address: f4cf.e237.a524 (bia f4cf.e237.a524)
  MTU 9216 bytes, BW 80000000 Kbit, DLY 10 usec
  reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, medium is broadcast

It is a relief to read that! 

It is a relief to read that!  I thought I was going to have to configure the peer-link MTU on-the-fly, with all the potential production impact that might have!  So thank you.