H3C Technologies H3C S7500E Series Switches - Manual (Page 128)

9-2
Uplink/Downlink ports
Uplink port and downlink port are two port roles in monitor link groups:
z Uplink ports refer to the monitored ports. The state of a monitor link group adapts to that of its
member uplink ports. When a monitor link group contains no uplink port or all the uplink ports are
down, the monitor link group becomes down; as long as one member uplink port is up, the
monitor link group stays up.
z Downlink ports refer to the monitoring ports. The state of the downlink ports in a monitor link
group adapts to that of the monitor link group. When the state of a monitor link group changes, the
state of its member downlink ports change accordingly. In this way, the state of the downlink ports
in a monitor link group is always consistent with that of the monitor link group.
Uplink/Downlink
The uplink is the link that connects the uplink ports in a monitor link group, while the downlink is the
link that connects the downlink ports.
How Monitor Link Works
A monitor link group works independently of other monitor link groups. When a monitor link group
contains no uplink port or all its uplink ports are down, the monitor link group goes down and forces all
downlink ports down at the same time. When any uplink port goes up, the monitor link group goes up
and brings up all the downlink ports.
You are recommended not to manually shut down or bring up the downlink ports in a monitor link
group.
Configuring Monitor Link
Configuration Prerequisites
Before assigning a port to a monitor link group, make sure the port is not the member port of any
aggregation group or service loopback group.
Creating a Monitor Link Group
Follow these steps to create a monitor link group:
To do… Use the command… Remarks
Enter system view system-view —
Create a monitor link group and enter
monitor link group view
monitor-link group group-id Required