To the best of my knowledge the IP address of posters to the boards are no longer grabbed during the posting process. At one time they were, but it didn't prove overly effective in stopping board spammers. One of our most notorious spammers was traced by IP address to the Los Angeles Public Library. The entire library and its users couldn't be blocked--so the spammer couldn't effectively be stopped from posting. There isn't any way at present to block someone from posting to the boards.
Joan