Cisco Switch feature or not ?

Perhaps you are thinking of BPDUguard?

Thanks for the reminder.

Once I though that, but it is none of Root Guard, BPDU Guard, Loop Guard nor UDLD Guard, any other Guard I did not mention ?

Meanwhile, at the comp.dcom.sys.cisco Job Justification Hearings, snipped-for-privacy@yahoo.com.hk chose the tried and tested strategy of:

You forgot Coldstream Guard.

maybe these options?

switchport port-security maximum {max # of MAC addresses allowed}: You can use this option to allow more than the default number of MAC addresses, which is one. For example, if you had a 12-port hub connected to this switch port, you would want to allow 12 MAC addresses =97one for each device. The maximum number of secure MAC addresses per port is 132.

switchport port-security violation {shutdown | restrict | protect}: This command tells the switch what to do when the number of MAC addresses on the port has exceeded the maximum. The default is to shut down the port. However, you can also choose to alert the network administrator (i.e., restrict) or only allow traffic from the secure port and drop packets from other MAC addresses (i.e., protect).

switchport port-security mac-address {MAC address}: You can use this option to manually define the MAC address allowed for this port rather than letting the port dynamically determine the MAC address

Thanks so much for your suggestion.

I shall check about the coldstream Guard.

Meanwhile, I do not think Port-security is the solution. Its operation is to cause switch port to shut down/disabled whenever extra MAC address violates the granted security rules. Cheers

r snipped-for-privacy@hotmail.com"

coldstream guard seems not related to network world !

The command you are looking for is called "Link state group 1 upstream/downstream" It is a interface command. Look into the Catalyst command ref:

np Regards Martin

Hi, Martin,

Thanks so much for your help. I shall check if the feature is fit....but it should be a great help.

BTW, we found the EEM feature may also be helpful.

Cheers

Verified....this is the tool !

Cheers