How do I run multiple forums sharing same users

[mgurain]

Hello,,

I am planning to run multiple specialized forums (different kind of information: sport forum, medical forum, computer science forum & may be others) all in one domain but different sub-domains, which will share the same user profiles (who ever sign-up in one forum will be able to post in any one of them).

example:

a.mysite.com -----> sport forum(s)
b.mysite.com -----> medical forum(s)
c.mysite.com -----> computer science forum(s)

How can I do it ?

thanks in advance,,