Boston Linux & UNIX was originally founded in 1994 as part of The Boston Computer Society. We meet on the third Wednesday of each month at the Massachusetts Institute of Technology, in Building E51.

BLU Discuss list archive


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Discuss] business class ISP recommendations



> From: discuss-bounces+blu=nedharvey.com at blu.org [mailto:discuss-
> bounces+blu=nedharvey.com at blu.org] On Behalf Of Tom Metro
> 
> Comcast Business cable Internet

I have used Comcast Business, and I'm the same as you - I would love to avoid using any of those companies ever again, but *especially* comcast, based on this experience.

We had a satellite office, and we had Comcast Business cable in there, as well as a T1.  We needed to ssh from the home office into the firewall of the satellite office, but it wasn't working.  We traced it down:  If you try to connect to port 22 of the external IP of the comcast business IP address, then the packet never reaches the destination.  But if you ssh to the T1 IP address, traffic gets through just fine.  This proved that comcast was blocking inbound port 22, and *not* a failure of the sending side to send the traffic.  We hooked up packet sniffers on both the sending side, and each of the receiving sides, and saw the packets go out from the home office, destined to each the comcast IP and the T1 IP.  We saw the packets arrive on the T1, but not comcast.  Other types of traffic worked fine.  It was only port 22 that was blocked.  I seem to recall we couldn't change the ssh listen port, because it was a PIX or something, but that particular detail is cloudy now.  (This happened about 5 years ago.)  

Could not possibly be any more definitive proof that comcast was blocking port 22.

Comcast denied it despite hours on the phone with them.  Problem was never resolved.



BLU is a member of BostonUserGroups
BLU is a member of BostonUserGroups
We also thank MIT for the use of their facilities.

Valid HTML 4.01! Valid CSS!



Boston Linux & Unix / webmaster@blu.org