[Discuss] business class ISP recommendations

[gaf at blu.org (Jerry Feldman)]

On 05/08/2014 08:51 AM, Edward Ned Harvey (blu) wrote:
>> 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.  (T
>  his 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.
> _______________________________________________
>
I don't have Comcast business class at home, but I do have Comcast
residential. I use a different port number for SSH and it works
reasonably well. But, on my tests, port 22 has also worked.

-- 
Jerry Feldman <gaf at blu.org>
Boston Linux and Unix
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