You have squid or some other forward http proxy set up to share a cache among all the devices on your network set up to access the Web, to minimize duplicate traffic?

And you have a shared caching DNS server set up locally, something like BIND?

Oh. You don’t. Well, that’s probably okay. I mean, it probably doesn’t matter that your devices are pulling duplicate copies of data down. Not everyone can have a network that minimizes latency and avoids inefficiency across devices.