mutin-sa

Google Public NTP [AS15169]:

time.google.com

time1.google.com

time2.google.com

time3.google.com

unixfox

Some hosting providers like scaleway allows to remove the IPv4 from the VPS in order to save 1€/month but doing this will result in losing connectivity to the "IPv4 world".
Or you may have ordered a VPS that only has IPv6 connectivity and you want to access to a resource only accessible from the "IPv4 world".
Here is how to gain your access back to the "IPv4 world".

Change your name servers(s) to DNS64 name servers(s)

Note: You may deploy your own DNS64 & NAT64 server on a separate server by following this tutorial (untested): https://packetpushers.net/nat64-setup-using-tayga/.
Note²: You may find a explanation of what is NAT64 and DNS64 on Wikipedia.

1. Choose a/multiple DNS64 public server(s) that has/have its own NAT64 public service from this list:

varnav

#!/bin/bash -ex

# Script will install multiple ADS-B feeders to Raspberry Pi OS
# Before running make sure you have your coordinates (lat/lon in a form of DD.DDDD) and antenna height (in both feet and m) handy.

if [ "$EUID" -ne 0 ]
  then echo "Please run as root"
  exit
fi