Aug 18:

PACKET FILTERING

QuakeWorld supports two types of filtering: IP packet filtering and user id 
filtering.  Userid filtering is the most convenient way to keep a specific 
person off of a server, but because anyone can create as many accounts as 
they want, a malicious user could just keep logging back in with a new 
account.  If their ip address is banned, they won't be able to log on with 
any account from that computer.  Unfortunately, most dialup accounts give 
a different ip address for each connection, so you may be forced to ban an 
entire subnet to keep a specific person off.

You can add or remove addresses from the filter list with:

addip 
removeip 

The ip address is specified in dot format, and any unspecified digits will 
match any value, so you can specify an entire class C network with "addip 
192.246.40".

Removeip will only remove an address specified exactly the same way.  You 
cannot addip a subnet, then removeip a single host.

iplist
Prints the current list of filters.

writeip
Dumps "addip " commands to iplist.cfg so it can be execed at a later date.  
The filter lists are not saved and restored by default, because I beleive 
it would cause too much confusion.

filterban 

If 1 (the default), then ip addresses matching the current list will be 
prohibited from entering the game.  This is the default setting.

If 0, then only addresses matching the list will be allowed.  This lets you 
easily set up a private game, or a game that only allows players from your 
local network.