Someone I know's having a problem connecting to random websites (Netflix, BBC news, etc.). Facebook, Google and loads more are working. I thought it could be a DNS issue, so I got him to change his DNS servers to Google's (8.8.8.8 and 8.8.4.4). I got him to do a tracert to netflix before and after changing DNS servers.
Before
After
As you can see, there's no change. I suspect it's a ISP routing issue, but my knowledge of networking is terrible.