To find services running on a linux machine open the /etc/services file. I will list all the services running on the server and what they are. Here is a partial list...

 ... tcpmux 1/tcp # TCP port service multiplexer echo 7/tcp echo 7/udp discard 9/tcp sink null discard 9/udp sink null systat 11/tcp users daytime 13/tcp daytime 13/udp netstat 15/tcp qotd 17/tcp quote msp 18/tcp # message send protocol msp 18/udp chargen 19/tcp ttytst source chargen 19/udp ttytst source ftp-data 20/tcp ftp 21/tcp fsp 21/udp fspd ... 																

$ sudo apt-get install nmap $ nmap 192.168.24.130

To check what services are running on the server use nmap. It has to be installed on Debian but that isn't that complicated. Do this...

To scan ports type the name of the program nmap and the ip address to scan...

nmap lists ports that are opened. The output should look something like this...

 kennyl:savage:/etc > nmap 192.168.24.130  Starting Nmap 5.00 ( http://nmap.org ) at 2013-01-28 18:44 MST Interesting ports on savage (192.168.24.130): Not shown: 985 closed ports PORT STATE SERVICE 21/tcp open ftp 22/tcp open ssh 53/tcp open domain 80/tcp open http 110/tcp open pop3 111/tcp open rpcbind 139/tcp open netbios-ssn 143/tcp open imap 445/tcp open microsoft-ds 901/tcp open samba-swat 993/tcp open imaps 2049/tcp open nfs 3306/tcp open mysql 8009/tcp open ajp13 8080/tcp open http-proxy  Nmap done: 1 IP address (1 host up) scanned in 0.57 seconds  																

If there are services running that aren't listed with nmap, well that's interesting.