Start FreeRadius 4.0 with rlm_tacacs failed due to segV error

[Alan DeKok]

On Apr 24, 2025, at 5:12 AM, bryan xiang <bryanxiang82 at gmail.com> wrote:
> 
> I changed some virtual server side config and tried to logon with
> testuser1/testpass123, the error from tacacs is an encoding error.

  Two things.  First, you have to say what attributes are going into the TACACS+ packet.  The server can't just invent things.

  Second, the rlm_tacacs module can only be run within a 'tacacs' namespace.  This is one of the major differences between v3 and v4.

  If you want to receive a RADIUS Access-Request and then send a TACACS+ packet, you will have to change namespaces.  See https://www.freeradius.org/documentation/freeradius-server/4.0.0/reference/unlang/subrequest.html


recv Access-Request {
	subrequest @tacacs::Authentication-Start {
		User-Name := parent.request.User-Name
		User-Name := parent.request.User-Password
		... fill in other attributes here, from dictionary/tacacs/*

		tacacs
		
	}


  You will have to edit this and double-check it, but the basic concepts are there.

  Alan DeKok.