I manage a weekly rental house that includes wireless Internet access. I've allowed all outbound ports on my router but my ISP has disabled my Internet access twice now because guests have downloaded (or served up) copyrighted content. So I'd like to institute some port filtering to discourage p2p sharing (see disclaimer below). But I don't want to inconvenience the 99.9% of folks who keep things above-board.

My question is, what outbound ports are typically open for rental/hotel wireless Internet access, or where can I find such a list? TCP 80,443,25,110 at a minimum. Though my own email service uses 995 and 465 for SSL, some may use IMAP, I personally use SSH and FTP, so I'll open those. Roughly I figure I need to open access to privileged ports, and close 1024 & above. Is there a whitelist I should institute for commonly used high ports? And does it make sense to block UDP > 1024 ?

Disclaimer: I realize anyone replying to this message could circumvent the port filtering and share content to their heart's content. I do not need comprehensive p2p blocking, which requires more than a port whitelist. Anyone staying at the house shoulders the responsibility for their Internet use, per the rental contract. Also anyone savvy enough to circumvent the port filters would hopefully be savvy enough to use some sort of peer blocking, thereby preventing the ISP from taking down the service.