Most importantly use the -dedicated command-line parameter. Followed by the number of players you wish to have on the server. Max value is 16. Also, setting +deathmatch 1 or +coop 1 to determine a game mode. Or as mono quickly illustrated, use the -game parameter which points to the folder name of the mod you wish to use. If u just want normal quake DM then dont use the -game parameter.
Some other things like, -zone or -mem might be required depending on the mod u are using. Read the docs that came with the mod....
edit: actually if you read the 1st post on this thread you'd find...
Actual Setup: #5 A Command Line
In a LAN game, a command line might go like this:
c:/quake/wqpro.exe -game crmod –dedicated 16 –condebug –heapsize 32768 –zone 1024 +map dm6
In the above:
0.) wqpro.exe is the ProQuake dedicated engine, basically an improved WinQuake.
1.) -game crmod is an example where c:\quake\crmod is where the progs.dat and other mod files reside.
2.) -dedicated 16 is an example where the server is setup to allow 16 players to connect
3.) -condebug generates a qconsole.log text file of events on the server, a server log.
4.) -heapsize 32768 is a memory allocation of 32 MB. -mem 32 could be substituted with some engines.
5.) -zone 1024 is another memory allocation of 1 MB for alias memory.
6.) +map dm6 is the map the server starts on.
But on a public hosted server, particularly Linux, it usually gets just a bit more complicated.
z:/servers/myaccount/sqpro –game xctf –dedicated 8 –noipx –condebug –heapsize 32768 –
zone 1024 –ip 126.96.36.199 –udpport 26000 +map e1m7
1.) Your folder on the server in this case might be something like z:\servers\myaccount
2.) In this example, sqpro is the Linux ProQuake binary.
3.) -ip 188.8.131.52 is the IP address to use for the connection
4.) -udpport 26000 is the connection port. 26000 is the most desired port, the Quake default, meaning that clients can connect without indicating the port #. In this example, someone could connect typing CONNECT 184.108.40.206, but with other ports they would need to type CONNECT 220.127.116.11:26001 (you'd want to get a DNS for the IP alias, but you often won't have that when you are doing initial setup.)