Questions about: dns

How do I find out my DNS server addresses under Linux, UNIX, Apple OS X, MS-Windows operating system? What is my dns server IP address under MS-Windows operating systems? Can you specify a list of public DNS server for personal use or game consoles?
If you ever need to set custom DNS or change the DNS settings on iOS devices for using an alternate domain name server or a faster one, you’ll probably want the DNS changes to take effect immediately, which requires the flushing of DNS caches on the