R3166-R3206-HP High-End Firewalls Network Management Command Reference-6PW101

Table Of Contents
19
Default level
2: System level
Parameters
external: Enables external loopback testing on an Ethernet interface.
internal: Enables internal loopback testing on an Ethernet interface.
Description
Use the loopback command to enable loopback testing on an Ethernet interface .
Use the undo loopback command to disable loopback testing on an Ethernet interface.
By default, loopback testing is disabled on Ethernet interfaces.
NOTE:
Enable loopback testing for troubleshooting purposes, such as identifying an Ethernet problem.
During loopback testing, the speed, duplex, mdi, and shutdown commands are not available. In
addition, the port is operating in full-duplex mode, regardless of its duplex configuration. After
loopback testing is disabled, the duplex configuration of the port is restored.
Examples
# Enable internal loopback testing on GigabitEthernet 0/0.
<Sysname> system-view
[Sysname] interface gigabitethernet 0/0
[Sysname-GigabitEthernet0/0] loopback internal
mtu
Syntax
mtu size
undo mtu
View
Layer 3 Ethernet interface view, Layer 3 Ethernet subinterface view
Default level
2: System level
Parameters
size: Sets the maximum transmission unit (MTU), ranging from 46 to 1500 bytes.
Description
Use the mtu command to set the MTU for an Ethernet interface or subinterface.
Use the undo mtu command to restore the default.
By default, the MTU of an Ethernet interface is 1500 bytes.