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radlogin is a /bin/login replacement which gets called by a getty to log in a user and to setup the user's login environment.

Normal login programs just check the login name and password which the user entered against the local password file (/etc/passwd, /etc/shadow). In contrast to that Radiusclient also uses the RADIUS protocol to authenticate the user.

Principles of operation

When radlogin gets invoked by your systems's getty, it behaves like the normal login program to the user.

First it asks the user for his login name (if not supplied by getty) and his password.

Then it tries to find the login name either through a RADIUS request, in the local passwd file or through both methods.

If the user is authenticated locally radlogin calls the local login program to spawn a standard login environment.

If the user is successfully authenticated via RADIUS, radlogin calls a special login program which gets the information that was passed from the RADIUS server in environment variables.

In this special login program you can now either start a telnet/rlogin session or start up SLIP/CSLIP or even PPP based on the information from the RADIUS server. You may also send RADIUS accounting information to a RADIUS server using the radacct program which is also part of the Radiusclient package.


Install the Radiusclient package

The installation procedure will only install a dummy login.radius script which just outputs all RADIUS_* environment variables and then exits.

You need to write your own login.radius if you want that the script does something useful. See the login.radius directory for example scripts.

You will have to look into radiusclient.conf and edit it.

Add the following two line to /etc/services if you don't already have them:

 radius          1645/udp	# RADIUS access requests
 radacct         1646/udp	# RADIUS accounting requests

Configure your getty to execute radlogin instead of the normal login process. The method of how to do this varies from getty to getty.

If you're using getty_ps you can set the LOGIN directive in the respective config file.

agetty has a command line option (-l) which allows you to specify an alternate login program, i.e. radlogin

With mgetty you add the following line to your login.cfg file:

 *       -       -       /radlogin @

We suggest you use either mgetty or getty_ps. mgetty even has a nice automatic PPP detection feature, which can be useful.

Appendix: Command line flags


Path to an alternative configuration file
File name of the terminal used to determine what to send in the NAS-Port attribute. Normally the tty of stdin is used.
Disable display if the radlogin issue file. This option is set by default if radlogin is called with an argument.
Display version information
Display usage information


File name of the terminal used to determine what to send in the NAS-Port attribute. Normally the tty of stdout is used.
Display version information
Display usage information


Display version information
Display usage information

See Also