Further to my previous post, DNS Speed Testing on Telstra nbn in Melbourne, I’ve used the Traceroute command to measure how far away (or how many hops away) the fastest DNS servers are.
Of course, my router’s DNS server is just one hop away, and it caches DNS replies, so this will be the fastest for everything that has been looked up recently (~1 hour – 1 day)
Then, unsurprisingly enough, the two Telstra DNS servers for Victoria are the next closest, with each of them being just 4 hops away.
traceroute 184.108.40.206 traceroute to 220.127.116.11 (18.104.22.168), 64 hops max, 52 byte packets 1 router.automatica.private (xx.xx.xx.xx) 0.631 ms 0.254 ms 0.277 ms 2 * * * 3 22.214.171.124 (126.96.36.199) 8.531 ms 8.483 ms 8.548 ms 4 dns-cust.lon.bigpond.net.au (188.8.131.52) 7.973 ms 7.914 ms 8.848 ms
traceroute 184.108.40.206 traceroute to 220.127.116.11 (18.104.22.168), 64 hops max, 52 byte packets 1 router.automatica.private (xx.xx.xx.xx) 0.590 ms 0.301 ms 0.279 ms 2 * * * 3 22.214.171.124 (126.96.36.199) 8.457 ms 8.381 ms 8.969 ms 4 dns-cust.win.bigpond.net.au (188.8.131.52) 8.274 ms 7.827 ms 9.758 ms
After this, CloudFlare 184.108.40.206 and OpenDNS were the next closest – with each of them 7 hops away. Judging by the ping times and hostnames of routers before them, I’m betting they are anycast to mirrors in Melbourne and likely located on Telstra’s network.
Google’s DNS servers, 220.127.116.11 and 18.104.22.168 are hosted in Sydney (again making educated guesses from ping times and hostnames) with 2x – 2.5x the latency of the DNS resolvers in Melbourne.
Other DNS resolvers, such as Quad 9, 22.214.171.124, look to be serving me content from the USA with 20x – 40x the latency of DNS resolvers located in Australia. They will most likely also be redirecting me towards overseas Akamai (etc) mirrors, so I really do not recommend using any of them.