Configure Ip-Mtu Vlan - Extreme Networks ExtremeWare XOS Command Reference Manual

Commands for Configuring Slots and Ports on a Switch

configure ip-mtu vlan

configure ip-mtu <mtu> vlan <vlan_name>
Description
Sets the maximum transmission unit (MTU) for the VLAN.
Syntax Description
mtu
vlan_name
Default
The default IP MTU size is 1500.
Usage Guidelines
NOTE
The BlackDiamond 8800 family of switches (formerly known as Aspen) and the Summit X450 switch do not support
fragmentation of any IP packets they forward. Also, the BlackDiamond 8800 family of switches and the Summit
X450 switch do not support the router specification for 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
4 bytes 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 command sets the MTU size to 2000 for VLAN sales:
configure ip-mtu 2000 vlan sales
286
IP maximum transmission unit (MTU)
Specifies the
1500 to 9216.
Specifies a VLAN name.
value. Range is from
ExtremeWare XOS 11.3 Command Reference