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