Comcast residential DNS contact

Scott Helms khelms at
Wed Dec 3 18:41:49 UTC 2014

It's also entirely possible that the behavior observed will change because
of testing.  The more a test looks different from "normal" residential
traffic the more likely that it's going to be handled differently.

Scott Helms
Vice President of Technology
(678) 507-5000

On Wed, Dec 3, 2014 at 1:37 PM, Christopher Morrow <morrowc.lists at>

> On Wed, Dec 3, 2014 at 12:54 PM, Grant Ridder <shortdudey123 at>
> wrote:
> > Hi Everyone,
> >
> > Thanks for the replies!  After reading them, i am doing some digging into
> > DNS RFC's and haven't found much with respect to ANY queries.  Not
> > responding with full results to protect against being used in an attack
> > makes sense.  However, I find it odd that only 1 of the 4 anycast
> servers I
> > tried would institute this.
> it's possible (jason hinted at this) that the servers in question are
> not a homogeneous software set... and have different behaviour being
> displayed because of that.
> Also, just because you sent a packet to 4 different ip addresses
> doesn't mean that they didn't end up on one or some of the same hosts
> behind loadbalancers/ecmp/etc, right? (so it's not clear you are/can
> test this properly from your vantage point)
> -chris
> (what's a bit concerning is my comcast link's not able to talk to
> cdns02 at all... over ipv4 at least, v6 works, thankfully I suppose)

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