R0106-HP MSR Router Series Interface Command Reference(V7)

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Predefined user roles
network-admin
Parameters
local: Enables internal loopback.
remote: Enables external loopback.
Usage guidelines
Loopback is intended for testing only. Disable the feature when the interface is operating correctly.
Before you use this command on a POS interface, change its clock mode to master. The loopback
function cannot work when the interface uses the slave clock mode.
When you enable loopback on a PPP-enabled POS interface, the state of the data link layer protocol is
reported up.
Examples
# Enable internal loopback on POS 2/2/0.
<Sysname> system-view
[Sysname] interface pos 2/2/0
[Sysname-Pos2/2/0] loopback local
Related commands
clock
mtu
Use mtu to set the MTU size for an interface.
Use undo mtu to restore the default.
Syntax
mtu size
undo mtu
Default
The default setting is 1500 bytes.
Views
Standard POS interface view, POS channel interface view
Predefined user roles
network-admin
Parameters
size: Sets the maximum transmission unit (MTU) in bytes. The value range for this argument is 128 to
1650 .
Usage guidelines
The MTU setting affects the assembly and fragmentation of IP packets.
After configuring the MTU for an interface, you must use the shutdown command and then the undo
shutdown command on the interface for the modification to take effect.