Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) User Manual
Page 326
Interface Commands
Software Reference for x310 Series Switches
12.6
AlliedWare Plus
TM
Operating System - Version 5.4.4C
C613-50046-01 REV A
mtu
Use this command to set the Maximum Transmission Unit (MTU) size for VLANs, where
MTU is the maximum packet size that VLANs can transmit. The MTU size setting is applied
to both IPv4 and IPv6 packet transmission.
Use the no variant of this command to remove a previously specified Maximum
Transmission Unit (MTU) size for VLANs, and restore the default MTU size (1500 bytes) for
VLANs.
Syntax
mtu <mtu-size>
no mtu
Default
The default MTU size is 1500 bytes for VLAN interfaces.
Mode
Interface Configuration for VLAN interfaces.
Usage
If a switch receives an IPv4 packet for Layer 3 switching to another VLAN with an MTU size
smaller than the packet size, and if the packet has the ‘don’t fragment’ bit set, then the
switch will send an ICMP ‘destination unreachable’ (3) packet type and a ‘fragmentation
needed and DF set’ (4) code back to the source. For IPv6 packets bigger than the MTU size
of the transmitting VLAN interface, an ICMP ‘packet too big’ (ICMP type 2 code 0) message
is sent to the source.
Note that
output will only show MTU size for VLAN interfaces.
Examples
To configure an MTU size of 1500 bytes on interface vlan2, use the commands:
To configure an MTU size of 1500 bytes on interfaces vlan2 to vlan4, use the
commands:
To restore the MTU size to the default MTU size of 1500 bytes on vlan2, use the
commands
Parameter
Description
<mtu-size>
<68-1500>
Specifies the Maximum Transmission Unit (MTU) size in bytes, where
1500 bytes is the default Ethernet MTU size for an interface.
awplus#
configure terminal
awplus(config)#
interface vlan2
awplus(config-if)#
mtu 1500
awplus#
configure terminal
awplus(config)#
interface vlan2-vlan4
awplus(config-if)#
mtu 1500
awplus#
configure terminal
awplus(config)#
interface vlan2
awplus(config-if)#
no mtu