I see what you're saying about DNS not being a factor in gaming, that makes perfect sense. I don't think his main issue is in gaming though, Once the route is logged it shouldn't be much of an issue, but it seems to be the case anyway. Maybe it's some other quirk with Comcast's service and not directly associated with the just the fact that we're talking about DNS servers but the routing from their domain helper server to the next hop. I don't know. Still, it may improve the service, even if we don't understand why, as I've seen. You know as well as I do that systems that look perfectly laid out on paper still end up needing troubleshooting for some unforeseen issue.

I also see how QoS wouldn't be a factor as you mention for LAN gaming--through just the switch and not involving the router. I still see it as an issue when going online when you have multiple devices on your network sharing a consumer level router. The router has to queue up packets regardless and giving certain devices priority in that queue helps. No home product will approach enterprise level equipment, but then it isn't handling nearly the processing either. We may not be configuring routing protocols and extensive ACL's here, but they still all have limits, and in the home, the limits are pretty low. You can't just look at this from an enterprise level perspective.

Bottom line: he needs to do some troubleshooting and there's no reason not to include my suggestions since it's impossible to know what all could be going on at Comcast's end. Sometimes you need to try what isn't obvious after trying what is obvious and then figure out why it helped.

That's one reason why I never have connectivity issues... I DO use enterprise quality equipment in my house My router is a Cisco 831 and my WAP is an 1130. I do use some crappy switches though because even the most low end Cisco switch has horrifically loud fans.

You do want to cover all of your bases when t-shooting, I was just trying to offer some suggestions to make the process more efficient.