3Com Switch 7750 Configuration Guide Guide

Leaf Node Configuration 245
[SW7750-Ethernet1/0/1] quit
[SW7750] stp pathcost-standard dot1d-1998
Port Priority
Configuration
Port priority is an important criterion on determining the root port. In the same
condition, ports with smaller port priority values are more potential to become the
root port than those with bigger priority values.
A port on a MSTP-enabled switch can have different port priorities and play
different roles in different spanning tree instances. This enables packets of
different VLANs to be forwarded along different physical paths, so that load
balancing can be achieved by VLANs.
You can configure port priority in the following two ways.
Configuring port priority in system view
Configuring port priority in Ethernet port view
Changing port priority of a port may change the role of the port and put the port
into state transition.
A smaller port priority value indicates a higher possibility for the port to become
the root port. If all the ports of a switch have the same port priority value, the port
priorities are determined by the port indexes. Changing the priority of a port will
cause spanning tree regeneration.
You can configure port priorities according to actual networking requirements.
Configuration example
# Configure the port priority of Ethernet1/0/1 port in spanning tree instance 1 to
be 16.
1 Configure in system view.
<SW7750> system-view
[SW7750] stp interface ethernet1/0/1 instance 1 port priority 16
2 Configure in Ethernet port view.
Table 177 Configure port priority for specified ports in system view
Operation Command Description
Enter system view system-view -
Configure port priority for
specified ports
stp interface interface-list
instance instance-id port
priority priority
Required
The default port priority is
128.
Table 178 Configure port priority for a specified port in Ethernet port view
Operation Command Description
Enter system view system-view -
Enter Ethernet port view
interface interface-type
interface-number
-
Configure port priority for the
port
stp [ instance instance-id ]
port priority priority
Required.
The default port priority is
128.