configure ip-mtu vlan

configure ip-mtu mtu [ {vlan} vlan_name | vlan vlan_list]

Description

Sets the maximum transmission unit (MTU) for the VLAN.

Syntax Description

mtu Specifies the IP maximum transmission unit (MTU) value. Range is from 1500 to 9194. However, CLI will allow the maximum limit upto 9216 considering port configuration such as tagging which influences L2 Header size. But the values greater than 9194 may lead to packet loss and hence not recommended.
vlan_name Specifies a VLAN name.
vlan_list Specifies a VLAN list of IDs.

Default

The default IP MTU size is 1500.

Usage Guidelines

BlackDiamond 8000 c-, e-, and xl-series modules, BlackDiamond X8 series switches, and Summit X440, X460, X460-G2, X480, X670, X670-G2 and X770 series switches support IP fragmentation and path MTU discovery.

Use this command to enable jumbo frame support or for IP fragmentation with jumbo frames. Jumbo frames are Ethernet frames that are larger than 1522 bytes, including 4 bytes used for CRC. Both endstations involved in the transfer must be capable of supporting jumbo frames. The switch does not perform IP fragmentation or participate in MTU negotiation on behalf of devices that do not support jumbo frames.

When enabling jumbo frames and setting the MTU size for the VLAN, keep in mind that some network interface cards (NICs) have a configured maximum MTU size that does not include the additional 4bytes of CRC included in a jumbo frame configuration. Ensure that the NIC maximum MTU is at or below the maximum MTU size configured on the switch. Frames that are larger than the MTU size configured on the switch are dropped at the ingress port.

If you use IP fragmentation with jumbo frames and you want to set the MTU size greater than 1500, all ports in the VLAN must have jumbo frames enabled.

Example

The following example sets the MTU size to 2000 for VLAN sales:

configure ip-mtu 2000 vlan sales

History

This command was available in ExtremeXOS 11.0.

The vlan_list option was added in ExtremeXOS 16.1.

Platform Availability

This command is available on BlackDiamond X8 switches, the BlackDiamond 8000 c-, e-, xl-, and xm-series modules, and the Summit X440, X460, X460-G2, X480, X670, X670-G2 and X770 series switches (whether or not included in a SummitStack).