said by delusion ftl :
It's important for everyone to understand that on the comcasts network ports are blocked by your very own cable modem. The config file clearly states which ports your cable modem is to block and it does so. Comcast only has pretty much one config type and it only blocks a handful of ports that does not include 80 or 21. They also have a config file they will send to your modem that blocks 25 if they feel you've abused the mail.
This means that 99% of the time when someone claims a port is being blocked (that is not in the generic config file) it is not comcast.
This is very good to know. Would you happen to have the list of ports that they do block, however? I'm just interested in why they would block some, but not hit the bigs ones like 80, 21, etc.
I can only assume that they block the ports for customer security, then?