How to disallow same IP being used at the same time?

[aileron79]

Hi everybody,

Before telling me that it is quite normal that a couple of users may use the same IP address please read my question carefully.

I am perfectly aware of the fact that some people may share the same IP address, i.e. people in companies, internet cafes and even a family at home can make use of NAT, Proxies etc. I am operating a really small forum. People interested in the forum's topic are scattered all over the world but there are only a very, very few of them. Two or more people sharing the same IP address by chance is an extremely improbable event.

Experience shows that if two users share the same IP, it is 99.99% a troll. When using WBB 2.3 we used to have a plugin that banned users sharing the same IP which proved to be very useful. It also was possible to define exceptions so that particular users or user groups were able to share the same IP at the same time.

So far, I have not found a plugin like that for VB4 but dozens of discussions about why this is not reasonable. Please, do not explain to me why it does not make any sense. I do know that something like this is nonsense in a large public forum but believe me, in my case it is a very useful tool to keep trolls out.

Any ideas?