3Com 7750 Series 1.1.19 loopback-detection per-vlan enable , 1.1.20 mdi

3Com Switch 7750 Series
Command Reference Guide — Basic Port Commands Chapter 1 Port Basic Configuration Commands
1-19
1.1.19 loopback-detection per-vlan enable
Syntax
loopback-detection per-vlan enable
undo loopback-detection per-vlan enable
View
Ethernet port view
Parameter
None
Description
Use the loopback-detection per-vlan enable command to enable loopback detection
for all the VLANs on the current trunk port or hybrid port.
Use the undo loopback-detection per-vlan enable command to enable loopback
detection for only the default VLAN on the current port.
By default, loopback detection is enabled for only the default VLAN of a trunk port or
hybrid port.
Note that this command is not available to access ports.
Example
# Enable loopback detection for all the VLANs on the trunk port GIgabitEthernet1/0/1.
<3Com> system-view
System View: return to User View with Ctrl+Z.
[3Com] interface GigabitEthernet 1/0/1
[3Com-GigabitEthernet1/0/1] port link-type trunk
[3Com-GigabitEthernet1/0/1] loopback-detection per-vlan enable
1.1.20 mdi
Syntax
mdi { across | auto | normal }
undo mdi
View
Ethernet port view
Parameter
across: Specifies the network cable to be crossover network cable.