3Com 4200G 12-Port Configuration Manual page 726

[Sysname-GigabitEthernet1/0/1] port isolate
[Sysname-GigabitEthernet1/0/1] quit
# Configure the access management IP address pool on GigabitEthernet 1/0/2.
[Sysname] interface GigabitEthernet 1/0/2
[Sysname-GigabitEthernet1/0/2] am ip-pool 202.10.20.25 26 202.10.20.55 11
# Add GigabitEthernet 1/0/2 to the port isolation group.
[Sysname-GigabitEthernet1/0/2] port isolate
[Sysname-GigabitEthernet1/0/2] quit
1-5