Mtu - Allied Telesis AR2050V Command Reference Manual

I C
NTERFACE OMMANDS

MTU

mtu
Overview 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.
mtu <68-1582>
Syntax
no mtu
Default The default MTU size is 1500 bytes for VLAN interfaces.
Mode Interface Configuration for VLAN interfaces.
Usage If a device 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 device 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 you cannot configure MTU on bridge interfaces. The MTU of the bridge
interface is determined by the member interface of the bridge which has the
lowest MTU. For example, if you attach eth1 with MTU 1200, ppp1 with MTU 1400,
and vlan1 with MTU 1500 to a bridge interface, the MTU for that interface will be
1200.
Note that
Examples To configure an MTU size of 1500 bytes on interface "vlan2", use the commands:
awplus#
awplus(config)#
awplus(config-if)#
To configure an MTU size of 1500 bytes on interfaces "vlan2" to "vlan4", use the
commands:
awplus#
awplus(config)#
awplus(config-if)#
To restore the MTU size to the default MTU size of 1500 bytes on "vlan2", use the
commands
awplus#
awplus(config)#
awplus(config-if)#
C613-50186-01 Rev B
show interface output will only show MTU size for VLAN interfaces.
configure terminal
interface vlan2
mtu 1500
configure terminal
interface vlan2-vlan4
mtu 1500
configure terminal
interface vlan2
no mtu
Command Reference for AR2050V
AlliedWare Plus™ Operating System - Version 5.4.7-1.x
377