How To Tell If Comcast Is Blocking Ports??

[prof]

Is there anyway to tell if comcast is blocking specific port numbers
on my high speed internet?? I download some sizeable files from
a friends site but lately I haven't been able to and I can't track down
why. I disabled my firewall and even removed the router but still end
up with the same results. I can connect to the site OK on port 5000
but accessing and dowloading files uses various ports 5004-5200
which I can no longer do. Could Comcast be blocking these ports??
How can I test for this??

TIA,
Prof

[olnacl]

There's been something in recent news about Comcrap limiting downloads on accounts that have been (in their opinion) overly active. Dunno the details on how they are doing it though.

[MacMagus]

> Could Comcast be blocking these ports?

More likely, your friend is blocking those ports with his own firewall, is failing to forward the ports to the appropriate computer or that service isn't operating on his server anymore.

> How can I test for this?

Find a server that has definitely got those ports open and do a port-scan from your home computer and from a second computer on a different network. If the second computer gets a response and yours doesn't then you're being blocked.

The Network Utility in your OS X Utilities folder does port scanning.

[wowzer]

I think in terminal, you can test your ports. Or go to:
http://www.grc.com/default.htm

search for Shields Up.