3Com Switch 8800 Advanced Software V5 Configuration Guide

Configuring the Root Bridge 119
The default packet format setting is auto, namely a port recognizes the two MSTP
packet formats automatically. You can configure the MSTP packet format to be
used by a port as 802.1s-compliant standard format or compatible format using
corresponding commands. After the configuration, when working in MSTP mode,
the port sends and receives only MSTP packets of the format you have configured.
Configuration procedure
Follow these steps to configure the MSTP packet format for a port or a group of
ports:
n
■ If the port is configured not to detect the packet format automatically while it
works in the MSTP mode, and if it receives a packet in the format other than as
configured, that port will become a designated port, and the port will remain
in the discarding state to prevent the occurrence of a loop.
■ If a port receives MSTP packets of different formats frequently, this means that
the MSTP packet formation configuration contains error. In this case, if the port
is working in MSTP mode, it will be shut down for protection.
Configuration example
# Configure port Ethernet 1/1/1 to receive and send standard-format MSTP
packets.
<Sysname> system-view
[Sysname] interface ethernet 1/1/1
[Sysname-Ethernet1/1/1] stp compliance dot1s
Enabling the MSTP
Feature
Configuration procedure
Follow these steps to enable the MSTP feature:
To do... Use the command... Remarks
Enter system view system-view -
Enter
Ethernet
interface
view or
port
group
view
Enter
Ethernet
interface
view
interface interface-type
interface-number
User either command
Configured in Ethernet interface
view, the setting is effective on
the current port only;
configured in port group view,
the setting is effective on all
ports in the port group
Enter port
group view
port-group { manual
port-group-name |
aggregation agg-id }
Configure the MSTP
packet format for the
port(s)
stp compliance { auto | dot1s |
legacy }
Optional
auto by default
To do... Use the command... Remarks
Enter system view system-view -
Enable the MSTP feature for
the device
stp enable Optional
By default, the MSTP feature
is enabled globally.