Address already in use /etc/freeradius/3.0/sites-enabled/default[68]: Error binding to port for 0.0.0.0 port 1812

Hi Moritz

Thank you for your reply
to answer your questions I was using
sudo freeradius stop,
so I gave it a try with systemclt as you suggested but eventhough I see the service was fully stop and there was no process latched to port 1812, once I restart freeradius and test it with -X I’m still getting the same error binding message: here’s what I did:

Administrator@optiplexmint:~$ sudo systemctl stop freeradius.service
Administrator@optiplexmint:~$ sudo systemctl status freeradius.service
● freeradius.service - FreeRADIUS multi-protocol policy server
   Loaded: loaded (/lib/systemd/system/freeradius.service; enabled; vendor preset: enabled)
   Active: inactive (dead) since Thu 2018-06-28 23:40:52 EDT; 23s ago
     Docs: man:radiusd(8)
           man:radiusd.conf(5)
           http://wiki.freeradius.org/
           http://networkradius.com/doc/
  Process: 10196 ExecStart=/usr/sbin/freeradius $FREERADIUS_OPTIONS (code=exited, status=0/SUCCESS)
  Process: 10194 ExecStartPre=/usr/sbin/freeradius $FREERADIUS_OPTIONS -Cxm -lstdout (code=exited, status=0/SUCCESS)
 Main PID: 10200 (code=exited, status=0/SUCCESS)
      CPU: 185ms

Jun 28 23:39:13 optiplexmint freeradius[10194]: rlm_mschap (mschap): authenticating by calling 'ntlm_auth'
Jun 28 23:39:13 optiplexmint freeradius[10194]: tls: Using cached TLS configuration from previous invocation
Jun 28 23:39:13 optiplexmint freeradius[10194]: rlm_cache (cache_eap): Driver rlm_cache_rbtree (module rlm_cache_rbtree
Jun 28 23:39:13 optiplexmint freeradius[10194]: Ignoring "sql" (see raddb/mods-available/README.rst)
Jun 28 23:39:13 optiplexmint freeradius[10194]: radiusd: #### Skipping IP addresses and Ports ####
Jun 28 23:39:13 optiplexmint freeradius[10194]: Configuration appears to be OK
Jun 28 23:39:13 optiplexmint freeradius[10194]: rlm_ldap (ldap): Removing connection pool
Jun 28 23:39:13 optiplexmint systemd[1]: Started FreeRADIUS multi-protocol policy server.
Jun 28 23:40:52 optiplexmint systemd[1]: Stopping FreeRADIUS multi-protocol policy server...
Jun 28 23:40:52 optiplexmint systemd[1]: Stopped FreeRADIUS multi-protocol policy server.

Administrator@optiplexmint:~$ sudo lsof -Pni:1812
Administrator@optiplexmint:~$ sudo systemctl start freeradius.service
Administrator@optiplexmint:~$ sudo freeradius -X
FreeRADIUS Version 3.0.12
Copyright (C) 1999-2016 The FreeRADIUS server project and contributors
....
Ignoring "sql" (see raddb/mods-available/README.rst)
 # Loading post-proxy {...}
 # Loading post-auth {...}
} # server default
server inner-tunnel { # from file /etc/freeradius/3.0/sites-enabled/inner-tunnel
 # Loading authenticate {...}
 # Loading authorize {...}
 # Loading session {...}
 # Loading post-proxy {...}
 # Loading post-auth {...}
} # server inner-tunnel
radiusd: #### Opening IP addresses and Ports ####
listen {
  	type = "auth"
  	ipaddr = *
  	port = 0
   limit {
   	max_connections = 16
   	lifetime = 0
   	idle_timeout = 30
   }
Failed binding to auth address * port 1812 bound to server default: Address already in use 
/etc/freeradius/3.0/sites-enabled/default[68]: Error binding to port for 0.0.0.0 port 1812
Administrator@optiplexmint:~$ 

any other suggestions?