Do some ISPs block VPN traffice (notably Comcast)

One of the folks in the office reported having trouble connecting to the office with Cisco VPN when he was at home.  I tested it; it worked fine in all environments.  He just moved to a new home and reports that he's "not sure" if he's ever connected successfully from his new house.  His new ISP is Comcast (with cable).  Does Comcast block VPN traffic?
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Rick_O_ShayConnect With a Mentor Commented:
ISPs generally don't block VPN traffic. The settings you use may be affected depending on how the equipment they provide is set up.
It appears that they do.
The following article says that this indeed the case.

There is no date on the article. Contact Comcast for the details.

Rick_O_ShayConnect With a Mentor Commented:
I thought since the FCC decree back when the old ATT was broken up that carriers could not control what you put on your connection? I would be an Ex-Comcast customer if this is accurate.
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amichaellConnect With a Mentor Commented:
Maybe this a location specific issue?  I have a physician working from home.  He is connecting with a site-to-site VPN (Cisco ASA on our end) over his Comcast connection (he has a static IP).
LMiller7Connect With a Mentor Commented:
Many ISP's routinely block specific types of traffic. My own ISP (in Canada) was for a time blocking ICMP, making ping impossible on the internet.
thegofConnect With a Mentor Commented:
This is more likely to be an issue with the router he is using in the new location (or it's configuration).  Some older ones had issues with supporting VPN, others need to be configured properly to support it.  I use Comcast myself for VPN all the time (and with Cisco software).
The Practically Networked article is apparently from 2001, a LONG time ago with respect to broadband policies (see page 13 in, or search for "comcast" in it).
jdanaAuthor Commented:
Thanks for the great feedback.
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