There seems to be a process called "cslistener" on my machine that is listening on port 9000. A scan using nmap resulted in this, where 172.29.137.150 is the address of my PC.
Nmap scan report for 172.29.137.150
Host is up (0.000013s latency).
Not shown: 993 closed ports
PORT STATE SERVICE
22/tcp open ssh
80/tcp open http
139/tcp open netbios-ssn
443/tcp open https
445/tcp open microsoft-ds
9000/tcp open cslistener
10000/tcp open snet-sensor-mgmt
What's going on here? I'm on ubuntu 12.04.
nmap doesn't show you which process is actually listening to some port but which service is registered with the IANA or otherwise known to use this port.
To find out which process is actually listening on that port you can use for example
It`s Sentry in default configuration - https://getsentry.com/
Most likely if you get this you are running php-fpm (PHP FastCGI Process Manager) which runs on port 9000 by default.
On my web/app servers I udpate
/etc/services
and change cslistener to fastcgi so alsof -i
makes more sense and another admin doesn't wonder what cslistener is.From what I've gathered from the internet, it might be your router's firewall, especially if you use a Buffalo router or firewall.