Quick Reference Guide

PowerConnect B-Series TI24X Configuration Guide 879
53-1002269-02
Configuring TACACS/TACACS+ security
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• Command authorization consults a TACACS+ server to get authorization for commands entered
by the user
When TACACS+ exec authorization takes place, the following events occur.
1. A user logs into the device using Telnet, or SSH.
2. The user is authenticated.
3. The device consults the TACACS+ server to determine the privilege level of the user.
4. The TACACS+ server sends back a response containing an A-V (Attribute-Value) pair with the
privilege level of the user.
5. The user is granted the specified privilege level.
When TACACS+ command authorization takes place, the following events occur.
1. A Telnet, SSH user previously authenticated by a TACACS+ server enters a command on the
device.
2. The device looks at its configuration to see if the command is at a privilege level that requires
TACACS+ command authorization.
3. If the command belongs to a privilege level that requires authorization, the device consults the
TACACS+ server to see if the user is authorized to use the command.
4. If the user is authorized to use the command, the command is executed.
TACACS+ accounting
TACACS+ accounting works as follows.
1. One of the following events occur on the device:
• A user logs into the management interface using Telnet or SSH
• A user enters a command for which accounting has been configured
• A system event occurs, such as a reboot or reloading of the configuration file
2. The device checks the configuration to see if the event is one for which TACACS+ accounting is
required.
3. If the event requires TACACS+ accounting, the device sends a TACACS+ Accounting Start
packet to the TACACS+ accounting server, containing information about the event.
4. The TACACS+ accounting server acknowledges the Accounting Start packet.
5. The TACACS+ accounting server records information about the event.
6. When the event is concluded, the device sends an Accounting Stop packet to the TACACS+
accounting server.
7. The TACACS+ accounting server acknowledges the Accounting Stop packet.
AAA operations for TACACS/TACACS+
The following table lists the sequence of authentication, authorization, and accounting operations
that take place when a user gains access to a device that has TACACS/TACACS+ security
configured.