Cisco 2509 - Router - EN User Manual page 504

Cisco IOS Issues
Condition
IETF RADIUS attributes not
supported in Cisco IOS 12.0.5.T
AAA client times out when
authenticating against
Windows NT/2000.
User Guide for Cisco Secure ACS for Windows Server
A-4
Appendix A
Recovery Action
Cisco incorporated RADIUS (IETF) attributes in Cisco IOS
Release 11.1. However, there are a few attributes that are not yet
supported or that require a later version of the Cisco IOS software.
The following attributes fall into this category:
Increase the TACACS+ timeout interval from the default, 5, to 20.
Set the Cisco IOS command as follows:
tacacs-server timeout 20
Troubleshooting Information for Cisco Secure ACS
78-14696-01, Version 3.1