How can I ban a user with a randomising ip address?

[corsacant]

As the title. I have a problem user who is using something to mask/randomise their ip address and is becoming a serious nuisance. Is there anything that would permanently and effectively ban them?

[notrious]

there is a hack in mods look up there

[corsacant]

Any idea of the name of it?
I've done a wide range ban of the ip address but I've a feeling he'll be back.