3Com 4500 Configuration Manual page 135

Network diagram
Figure 1-1 Network diagram for port isolation configuration
Configuration procedure
# Add Ethernet1/0/2, Ethernet1/0/3, and Ethernet1/0/4 to the isolation group.
<Sysname> system-view
System View: return to User View with Ctrl+Z.
[Sysname] interface ethernet1/0/2
[Sysname-Ethernet1/0/2] port isolate
[Sysname-Ethernet1/0/2] quit
[Sysname] interface ethernet1/0/3
[Sysname-Ethernet1/0/3] port isolate
[Sysname-Ethernet1/0/3] quit
[Sysname] interface ethernet1/0/4
[Sysname-Ethernet1/0/4] port isolate
[Sysname-Ethernet1/0/4] quit
[Sysname] quit
# Display information about the ports in the isolation group.
<Sysname> display isolate port
Isolated port(s) on UNIT 1:
Ethernet1/0/2, Ethernet1/0/3, Ethernet1/0/4
1-3