I was always told by colleagues 18.104.22.168 appears to work faster and have to combine that with Google's public DNS. Basically using 22.214.171.124 as primary and 126.96.36.199 as secondary. However, Google only provides 188.8.131.52 and 184.108.40.206, so who provides 220.127.116.11? And if true, why is 18.104.22.168 faster?
Note: These IP addresses are used to dig domains and to determine if local DNS changes has propagated over all over the internet.