With port security on a Cisco switch, if you configure 1 source MAC address, does that also set the maximum MAC addresses to only one?

  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can provide and accept your own answer.
    – Ron Maupin
    Commented Dec 14, 2019 at 19:39

1 Answer 1


Basically, yes. Defining a group of MAC addresses to an interface restricts the allowed MAC addresses to those defined in the group, which could be a group of one.

Cisco has documents to explain port security, if you search. For example, Chapter: Configuring Port Security:

You can use the port security feature to restrict input to an interface by limiting and identifying MAC addresses of the workstations that are allowed to access the port. When you assign secure MAC addresses to a secure port, the port does not forward packets with source addresses outside the group of defined addresses. If you limit the number of secure MAC addresses to one and assign a single secure MAC address, the workstation attached to that port is assured the full bandwidth of the port.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.