27.8.3 Changing the port to block

Points to note

The switchport isolation add command and switchport isolation remove command are used to change the ports blocked by the inter-port relay blocking functionality. If a port is specified in batch by switchport isolation <interface id list> on a port that has already been set, the setting is replaced by the specified setting.

Command examples

1. (config)# interface gigabitethernet 1/0/1

   (config-if)# switchport isolation interface gigabitethernet 1/0/2-10

   Switches to the Ethernet interface configuration mode of port 1/0/1, and blocks forwarding from ports 1/0/2 to 1/0/10 to port 1/0/1.

2. (config-if)# switchport isolation interface add gigabitethernet 1/0/11

   (config-if)# switchport isolation interface remove gigabitethernet 1/0/5

   Adds port 1/0/11 to the block to port 1/0/1. Also cancels the setting of port 1/0/5. In this state, communication from ports 1/0/2 to 1/0/4, 1/0/6 to 1/0/11 to port 1/0/1 is blocked.

3. (config-if)# switchport isolation interface gigabitethernet 1/0/3-4

   Sets ports 1/0/3 to 1/0/4 to block forwarding to ports 1/0/1. All previous settings are overwritten, only forwarding from ports 1/0/3 through 1/0/4 is blocked, and other ports can communicate.