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Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter10 Configuring IEEE 802.1x Port-Based Authentication
Understanding IEEE 802.1x Port-Based Authentication
802.1x Accounting
The 802.1x standard defines how users are authorized and authenticated for network access but does not
keep track of network usage. 802.1x accounting is disabled by default. You can enable 802.1x accounting
to monitor this activity on 802.1x-enabled ports:
User successfully authenticates.
User logs off.
Link-down occurs.
Re-authentication successfully occurs.
Re-authentication fails.
The switch does not log 802.1x accounting information. Instead, it sends this information to the
RADIUS server, which must be configured to log accounting messages.
802.1x Accounting Attribute-Value Pairs
The information sent to the RADIUS server is represented in the form of Attribute-Value (AV) pairs.
These AV pairs provide data for different applications. (For example, a billing application might require
information that is in the Acct-Input-Octets or the Acct-Output-Octets attributes of a RADIUS packet.)
AV pairs are automatically sent by a switch that is configured for 802.1x accounting. Three types of
RADIUS accounting packets are sent by a switch:
START–sent when a new user session starts
INTERIM–sent during an existing session for updates
STOP–sent when a session terminates
Table10-3 lists the AV pairs and when they are sent are sent by the switch:
Table10-3 Accounting AV Pairs
Attribute Number AV Pair Name START INTERIM STOP
Attribute[1] User-Name Always Always Always
Attribute[4] NAS-IP-Address Always Always Always
Attribute[5] NAS-Port Always Always Always
Attribute[8] Framed-IP-Address Never Sometimes1Sometimes1
Attribute[25] Class Always Always Always
Attribute[30] Called-Station-ID Always Always Always
Attribute[31] Calling-Station-ID Always Always Always
Attribute[40] Acct-Status-Type Always Always Always
Attribute[41] Acct-Delay-Time Always Always Always
Attribute[42] Acct-Input-O ctets Never Always Always
Attribute[43] Acct-Output-Octets Never Always Always
Attribute[44] Acct-Session-ID Always Always Always
Attribute[45] Acct-Authentic Always Always Always
Attribute[46] Acct-Session-Time Never Always Always