DNS: Recursion example

DNS: Recursion example

In this example, 128.104.254.254 or 144.92.254.254 is looking up the A record for "www.doit.wisc.edu". We will also assume that the dns server does not have any information cached. If there is valid cached information, the server simply serves the data out of the cache and the below steps are not performed. DNS recursion is an iterative process. The process is performed from 'right to left'. '.' is determined, then 'edu', then 'wisc.edu', then 'doit.wisc.edu', and finally 'www.doit.wisc.edu'.

root.hints

One well known location of the most recent root IPs is here:

wget ftp://ftp.rs.internic.net/domain/db.cache