Cistron RADIUS server

一款开源的 AAA  (Radius Server) 认证服务器，概要：

• It's free (under the GNU GPL license)
• Supports access based on huntgroups
• The users file is processed in order, multiple DEFAULT entries are possible, and all entries can optionally "fall through"
• Caches all config files in-memory, including the "users" file
• But it can also keep the users file in a DBM database file
• Keeps a list of logged in users (radutmp file aka session database)
• Logs both UNIX "wtmp" file format and RADIUS detail logfiles
• Supports Simultaneous-Use = X parameter. Yes, this means that you can now prevent double logins!
• Supports Vendor-Specific attributes, including USRs non-standard ones.
• Supports proxying
• Supports the "Alive" packet
• Can replicate accounting data between servers