Cisco Catalyst 2960 Series, Configuration Manual

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Because this command is session-oriented, it must be accompanied by one or more of the session identification
attributes described in the
“ Session Identification ” section. If the session cannot be located, the switch returns
a CoA-NAK message with the
“
Session Context Not Found
”
error-code attribute. If the session is located, the
switch disables the hosting port and returns a CoA-ACK message.
If the switch fails before returning a CoA-ACK to the client, the process is repeated on the new active switch
when the request is re-sent from the client. If the switch fails after returning a CoA-ACK message to the client
but before the operation has completed, the operation is restarted on the new active switch.
A Disconnect-Request failure following command re-sending could be the result of either a successful
session termination before change-over (if the Disconnect-ACK was not sent) or a session termination by
other means (for example, a link failure) that occurred after the original command was issued and before
the standby switch became active. Note
CoA Request: Bounce-Port
A RADIUS server CoA bounce port sent from a RADIUS server can cause a link flap on an authentication
port, which triggers DHCP renegotiation from one or more hosts connected to this port. This incident can
occur when there is a VLAN change and the endpoint is a device (such as a printer) that does not have a
mechanism to detect a change on this authentication port. The CoA bounce port is carried in a standard
CoA-Request message that contains the following VSA:
Cisco:Avpair="subscriber:command=bounce-host-port"
Because this command is session-oriented, it must be accompanied by one or more of the session identification
attributes. If the session cannot be located, the switch returns a CoA-NAK message with the
“
Session Context
Not Found
”
error-code attribute. If the session is located, the switch disables the hosting port for a period of
10 seconds, re-enables it (port-bounce), and returns a CoA-ACK.
If the switch fails before returning a CoA-ACK to the client, the process is repeated on the new active switch
when the request is re-sent from the client. If the switch fails after returning a CoA-ACK message to the client
but before the operation has completed, the operation is re-started on the new active switch.
CoA Session Query Command
The CoA session query command requests service information about a subscriber session. The AAA server
sends the request in a standard CoA-Request message containing the following VSA:
Cisco:Avpair=
“
subscriber:command=session-query
”
Because this command is session-oriented, it must be accompanied by one or more of the session identification
attributes described in the
Session Identification section below. If the device cannot locate a session, it returns
a CoA-NAK message with the
“
Session Context Not Found
”
error-code attribute. If the device locates a session,
it performs a session query operation on the session and returns a CoA-ACK message.
If the device fails before returning a CoA-ACK to the client, the process is repeated on the new active device
when the request is re-sent from the client. If the device fails after returning a CoA-ACK message to the client
but before the operation is complete, the operation is restarted on the new active device.
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
970
Information About RADIUS Change-of-Authorization