Trying to stop persistent hacker

[Stray Cat]

On our COD4 server we have a persistent hacker. This person is using a keygen so it is not possible to ban by guid. I have tried to mask their ip but they keep changing it.
So far I have tried a general mask of ip in pbbans.dat file using MASK124.171. which didn't work. Also have ip_guard in pbsv.cfg file using pb_sv_ipguard 124.171. also this failed.

pbsv.cfg
; ------------------------------
; IP Guard
; ------------------------------
pb_sv_ipguard 124.171.

pbbans.dat
[Manual Ban] MASK124.171. "|BFAM|Torbs" "keygen & hacker"

Any ideas would be most welcome.

[Edge100x]

Try:

pb_sv_banmask "124.171."

[Stray Cat]

Thanks. Will give it a go.