3Com SuperStack II 9300 Command Reference Manual page 325

Procedure
1 To enable MultiPoint Link Aggregation on the switch, use the
mpla mode enable
To disable MultiPoint Link Aggregation on the switch, use the
mpla mode disable
2 Select the ports that you want to be part of the multipoint aggregated
link using the
bridge trunk define
Chapter 11 .
3 Reboot the switch to implement the multipoint aggregated link selection.
On reboot, existing trunks and VLANs are deleted, and the default VLAN
is restored.
command.
command.
command, as described in
bridge mpla mode 325
bridge
bridge