A TACACS+ server that allows authorization and authentication via net
on remote access servers: Authenticate users, authorize commands and log
accounting information.

Version 4 has improved features and bugfixes over the older 2.x versions.

Improved features among others and bugfixes: Microsoft CHAP support.
To enable MSCHAP you need to optain a key from Microsoft, see the FAQ
section in the users guide. Therefore this isn't enabled by default.

Cisco, the original developers, have stopped tac_plus development around
F4.0.4. There are different versions based on Cisco tac_plus, this is the
version from Shrubbery Networks.

See also: https://www.shrubbery.net/tac_plus