Comcast possibly filtering some domains

Posted on October 13, 2008

This morning, I was having issues accessing certain news sites that I always visit, including the Louisville (Ky.) Courier-Journal and the Baltimore Sun. Of course, I figured it could be a million different things, from an Internet connection problem to an ad-serving issue to the hamsters not spinning their wheels fast enough to power the internets.

I could access them for a short period of time, then I couldn't again. Seeing as how I could access other websites, including my own, I thought I'd try to ping the domains. Pinging a domain just checks to verify that the address exists and it accepts requests. When doing this, I found very interesting information: the domains are being filtered. Here are the results of my pings:

PING ( 56 data bytes
36 bytes from Communication prohibited by filter
Vr HL TOS Len ID Flg off TTL Pro cks Src Dst
4 5 20 5400 4e22 0 0000 28 01 ee4f

PING ( 56 data bytes
36 bytes from ( Communication prohibited by filter
Vr HL TOS Len ID Flg off TTL Pro cks Src Dst
4 5 20 5400 a984 0 0000 2c 01 9fdf

I'm chatting with a Comcast representative right now. She says, "As of this moment, Comcast users may experience issues accessing sites. The issue has been escalated and is be investigated." Yeah, I'd say they are having problems because Comcast is attempting to filter results! That's just crazy.

UPDATES: A ping for at 10 a.m. EDT results in 100 percent packet loss. However, people not on Comcast can access the Baltimore Sun website with no problems.

10:20 a.m.: I sent an email to Kevin Cowherd at the Baltimore Sun to see if he wanted to follow up about this issue. I'm not positive he'll get the message, though, since his email domain is, and that is currently being filtered. The Comcast rep I'm communicating with, Mylene.25343, claims that they are not filtering any sites right now. When asked why it appears they are, she responded with this: "This is becase we are experiencing problems with our network. Some customers have even experienced redirecting to our home page and cannot access other sites at all."

10:40 a.m.: Mylene.25343 left the online chat, but before doing so, she gave me a list of other domains supposedly experiencing similar problems. I started checking the domains, and I can ping them with no problems. However, again shows as being filtered. A little checking shows that normally, the message "Communication prohibited by filter" can mean that it's a routing problem. With a little more checking, including a review of the Internet Traffic Report, it looks as if it could definitely be routing. At present time, there are two servers (Colorado and Virginia) that are down.

10:45 a.m.: It looks as if access to has been restored, at least, to me. I still receive a filtering error when trying to ping though.