Digitalchina Networks DCS-3950 series User Manual

345
DCS-3950 series Ethernet switch manual
no loopback-detection control
Function：Enable the function of loopback detection control on a port, the no operation of
this command will disable the function.
Parameters：shutdown set the control method as shutdown, which means to close down
the port if a port loopback is found.
block set the control method as block, which means to block a port by allowing bpdu
messages only if a port loopback is found.
learning disable the control method of learning MAC addresses on the port, drop
received messages and delete the MAC address of the port.
trap Only allow trap messages to be sent from the port.
Default：Disable the function of loopback diction control.
Command mode：Port Mode.
Usage Guide：If there is any loopback, the control operation will be cancelled after a
certain period of time after enabling it on the port, usually 2 seconds before sending the
next detection message. So, the detection interval should be as long as possible when
the function of loopback detection control is enabled on a port to avoid a repeated control
operation on the port. If the control method is block, the corresponding relationship
between instance and vlan id should be set manually by users.
Example：Enable the function of loopback detection control under ethernet 0/0/2 mode.
Switch(Config)#interface ethernet 0/0/2
Switch(Config-Ethernet0/0/2)#loopback-detection control shutdown
Switch(Config-Ethernet0/0/2)#loopback-detection control
22.2.2.2 loopback-detection specified-vlan
Command：loopback-detection specified-vlan <vlan-list>
no loopback-detection specified-vlan [<vlan-list>]
Function：Enable the function of loopback detection on the port and specify the VLAN to
be checked; the no operation of this command will disable the function of detecting
loopbacks through this port or the specified VLAN.
Parameters：<vlan-list> the list of VLANs allowed passing through the port. Given the
situation of a trunk port, the specified vlans can be checked. So this command is used to
set the vlan list to be checked.
Default：Disable the function of detecting the loopbacks through the port.
Command mode：Interface Mode.
Usage Guide：If a port can be a TRUNK port of multiple Vlans, the detection of loopbacks
can be implemented on the basis of port+Vlan, which means the objects of the detection
can be the specified Vlans on a port. If the port is an ACCESS port, only one Vlan on the
port is allowed to be checked despite the fact that multiple Vlans can be configured. This
function is not supported under Port-channel.
Example：Enable the function of loopback detection under ethernet 0/0/2 mode.
Switch(Config)#interface ethernet 0/0/2
Switch(Config-Ethernet0/0/2)#switchport mode trunk
Switch(Config-Ethernet0/0/2)#switchport trunk allowed vlan all

Digitalchina Networks DCS-3950 series Specifications

General

Brand	Digitalchina Networks
Model	DCS-3950 series
Category	Network Router
Language	English