How to Disable IPV6 on CentOS - Linux Hint
https://linuxhint.com/disable_ipv6_centosHow to Disable IPv6 on CentOS 7.5. IPv6 or Internet Protocol version 6 is the latest version of Internet Protocol (IP). IPv4 or Internet Protocol version 4 is already being widely used. But it has some limitations. The first one is that, IPv4 has 32-bit address scheme. That means only 4.3 billion unique address is possible with IPv4.
linux - How to disable AAAA lookups? - Server Fault
https://serverfault.com/questions/63266501.10.2014 · PS: Contrary to popular belief here on SF, there are some good reasons to disable IPv6/AAAA on a machine in a IPv4-only network, even where DNS works: Reduce broadcast load; Reduce load on DNS resolvers by almost 50%; Reduce connection start-up times (significantly where DNS caches are laggy); Follow best practices to disable non-functional features to …
Slow DNS with IPv6 - CentOS
forums.centos.org › viewtopicDec 11, 2015 · When making the same 'wget' request from this server A to download a file on server C (which has both IPv4 and IPv6), the command takes 1-2 minutes to resolve the DNS. It ultimately fails to resolve the IPv6 DNS and carries out the download via IPv4. I just added the following line under /etc/sysctl.conf. net.ipv6.conf.all.disable_ipv6 = 1.