Cisco Catalyst 2960 Series, Configuration Manual

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MAC Move
When a MAC address is authenticated on one switch port, that address is not allowed on another authentication
manager-enabled port of the switch. If the switch detects that same MAC address on another authentication
manager-enabled port, the address is not allowed.
There are situations where a MAC address might need to move from one port to another on the same switch.
For example, when there is another device (for example a hub or an IP phone) between an authenticated host
and a switch port, you might want to disconnect the host from the device and connect it directly to another
port on the same switch.
You can globally enable MAC move so the device is reauthenticated on the new port. When a host moves to
a second port, the session on the first port is deleted, and the host is reauthenticated on the new port. MAC
move is supported on all host modes. (The authenticated host can move to any port on the switch, no matter
which host mode is enabled on the that port.) When a MAC address moves from one port to another, the
switch terminates the authenticated session on the original port and initiates a new authentication sequence
on the new port. The MAC move feature applies to both voice and data hosts.
In open authentication mode, a MAC address is immediately moved from the original port to the new
port, with no requirement for authorization on the new port.
Note
MAC Replace
The MAC replace feature can be configured to address the violation that occurs when a host attempts to
connect to a port where another host was previously authenticated.
This feature does not apply to ports in multi-auth mode, because violations are not triggered in that mode.
It does not apply to ports in multiple host mode, because in that mode, only the first host requires
authentication.
Note
If you configure the authentication violation interface configuration command with the replace keyword,
the authentication process on a port in multi-domain mode is:
• A new MAC address is received on a port with an existing authenticated MAC address.
• The authentication manager replaces the MAC address of the current data host on the port with the new
MAC address.
• The authentication manager initiates the authentication process for the new MAC address.
• If the authentication manager determines that the new host is a voice host, the original voice host is
removed.
If a port is in open authentication mode, any new MAC address is immediately added to the MAC address
table.
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
1331
Information About 802.1x Port-Based Authentication