3Com MSR 50 Series Configuration Manual page 509

Port Isolation Configuration Example 509
<Device> system-view
[Device] interface ethernet 1/1
[Device-Ethernet1/1] port-isolate enable
[Device-Ethernet1/1] quit
[Device] interface ethernet 1/2
[Device-Ethernet1/2] port-isolate enable
[Device-Ethernet1/2] quit
[Device] interface ethernet 1/3
[Device-Ethernet1/3] port-isolate enable
# Display the information about the isolation group.
<Device> display port-isolate group
Port-isolate group information:
Uplink port support: NO
Group ID: 1
Ethernet1/1 Ethernet1/2 Ethernet1/3