Dell EMC SmartFabric OS10 User Guide Release 10.5.0

To return to the default MTU value, use the no mtu command. If an IP packet includes a L2 header, the IP MTU must be at least 32 bytes smaller than the L2 MTU.

• Port-channels
  • All members must have the same link MTU value and the same IP MTU value.
  • The port channel link MTU and IP MTU must be less than or equal to the link MTU and IP MTU values you configure on the channel members. For example, if the members have a link MTU of 2100 and an IP MTU 2000, the port channel’s MTU values cannot be higher than 2100 for link MTU or 2000 bytes for IP MTU.
• VLANS
  NOTE You must configure the MTU on VLAN members first before you configure the VLAN MTU.
  • All members of a VLAN must have the same MTU value.
  • Tagged members must have a link MTU 4 bytes higher than untagged members to account for the packet tag.
  • Ensure that the MTU of VLAN members is greater than or equal to the VLAN MTU. If you configure the MTU on VLAN members after you configure the VLAN MTU, the VLAN MTU may not be updated. OS10 selects the lowest MTU value configured on the VLAN or VLAN members to be the VLAN MTU.

  For example, the VLAN contains tagged members with Link MTU of 1522 and IP MTU of 1500 and untagged members with Link MTU of 1518 and IP MTU of 1500. The VLAN’s Link MTU cannot be higher than 1518 bytes and its IP MTU cannot be higher than 1500 bytes.

OS10(conf-if-eth1/1/7)# mtu 3000