IP Filter is one of the tabs in the KTorrent Configuration dialog.
The tab is intended to enable the use of a plain text blocklist, but so far I can't get it to work correctly.
The controls on the tab are:
PeerGuardian Filter File
[x] Use PeerGuardian filter (Checkbox)
If left unticked then all other controls on the tab are unavailable.
IP filter file: (Editable Text box)
Location of the plain text block list file. The location can be on the web or on the local file system.
Button which converts the text file into a format which KTorrent can use.
Update file every: (Checkbox) & linked Integer box.
Tick this checkbox to enable automatic updates of the blocklist (assuming a web location is entered in the IP Filter File Edit box above). If ticked, the linked Integer box will allow you to set the update frequency, in days.
Last Updated: (System Control)
A system updated text field which details when the last successful update occurred. If you can't get the IP filter to work it will report "No update done yet!".
Next Update: (System Control)
A system updated text field which details when the next update is scheduled to run. It changes each time you change the 'Update file every' Integer Box.