A few days last week things seemed a bit odd with my networking around the house. At first I blamed my stuff since I don’t have any redundancy on my stuff. Later I blamed Comcast. Then DNS. Then, finally, Comcast again — kinda.
The symtoms I was seeing was when I opened my browser and went to a site it was freakishly slow to start to load, then finished in a flash. The same symptoms were seen on two different machines so I was able to rule that out. Next I reset my cable modem and router to no avail.
Here’s where it became interesting.
So I hypothesized that DNS was messed up in some way. Sure enough when I did nslookups from my machine it alternated between taking a while and timing out. Interestingly, I was using Google’s DNS. Ok, a quick reconfig to use Comcast’s lead me to sometimes being redirected to the self-install page from Comcast — that wasn’t working either. Now this was just plain weird: I was able to send packets to the internet at large, mostly, but Comcast was hijacking the DNS and pointing elsewhere.
This is when I decided to go to speedtest.net.
Holy crap! This, I was not expecting.
DNS was still jibbered, but bits were moving across the wire. Fast.
The next day things seemed to have sorted themselves out, but my speed didn’t change at all. Maybe I just got caught in an upgrade.
Odd side note: consistently at the start I get well over 100Mb/s for a second or two before the connection gets throttled to only 60Mb/s. :-)