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