Explanation of polkitd Unregistered Authentication Agent

Question

In /var/log/secure every time a user logs in or logs out I notice the messages shown below stating Unregistered and Registered Authentication Agent. I have not been able to figure out why these messages keep occurring. Any help with understanding why these messages are occurring and/or if it is possible to fix them would be greatly appreciated.

Aug 25 09:00:40 TEST polkitd(authority=local): Unregistered Authentication Agent for session /org/freedesktop/ConsoleKit/Session18 (system bus name :1.4467, object path /org/gnome/PolicyKit1/AuthenticationAgent, locale en_US.utf8) (disconnected from bus)

Aug 25 13:03:19 TEST polkitd(authority=local): Registered Authentication Agent for session /org/freedesktop/ConsoleKit/Session2 (system bus name :1.43 [/usr/libexec/polkit-gnome-authentication-agent-1], object path /org/gnome/PolicyKit1/AuthenticationAgent, locale en_US.utf8)

Answer 1

Policykit is a system daemon and policykit authentication agent is used to verify identity of the user before executing actions. The messages logged in /var/log/secure show that an authentication agent is registered when user logs in and it gets unregistered when user logs out. These messages are harmless and can be safely ignored.

Answer 2

Different service trying to run on the same port

• I encoutered similar error when running newly installed nginx. Turns out that port 80 is being used by apache. Updating the default port fixed the problem

  local@machine:/$ sudo lsof -i -P -n | grep LISTEN   local@machine:/$ sudo vim etc/nginx/default  server  {   listen 86 default_server;  listen [::]:86 default_server;  .....  .. }