Display and Debug Ethernet Interface 113
Value ranges and default values of MTUs with different link layer protocol are
different. When Ethernet_II frame format is adopted, MTU value range will be
46-1500 bytes with the default value as 1500 bytes, and when Ethernet_SNAP
frame format is adopted, MTU value range will be 46-1492 bytes with default
value 1492 bytes.
5Select work rate of fast Ethernet interface
As described before, the fast Ethernet interface can work at rates of 10Mbps and
100Mbps. Therefore, it is possible to select interface working rate with following
command in Ethernet interface view.
Tabl e 90 Select working rate of fast Ethernet interface
The default is “negotiation”, i.e. the system automatically chooses an optimum
working rate. The user can also specify the interface working rate. But the rate
specified must be the same as that of the actually connected network.
6Select work mode of Ethernet interface
’s Ethernet interface should work in half duplex mode when connected with HUB
and in full duplex mode when connected with LAN Switch. Therefore, it is possible
to select working mode with the following command in Ethernet interface view.
Tabl e 91 Select working mode of Ethernet interface
The default is “negotiation”, i.e. the system automatically chooses an optimum
working mode.
7Enable or disable internal loopback and external loopback
When performing special functionality test on Ethernet interface, it needs to be
set as internal loopback and external loopback sometimes. Therefore, it is possible
to enable internal loopback and external loopback with the following commands
in Ethernet interface view.
Tabl e 92 Enable or disable internal loopback and external loopback
The default is to disable both internal loopback and external loopback.
Display and Debug
Ethernet Interface The following command can be used to view the state of Ethernet interface in all
views, so that the specified Ethernet interface can be displayed and debugged.
Tabl e 93 Display the state of specified Ethernet interface
Recover MTU default value undo mtu
Operation Command
Select working rate of fast Ethernet interface speed { 100 | 10 | negotiation }
Operation Command
Select working mode of Ethernet interface duplex { negotiation | full |
half }
Operation Command
Enable internal loopback and external loopback loopback
Disable internal loopback and external loopback undo loopback
Operation Command
Display the state of specified Ethernet
interface display interfaces ethernet
number