Routing Network Traffic - Proxies, Redirects and DNS
Archive - Originally posted on "The Horse's Mouth" - 2009-05-01 20:02:51 - Graham Ellis
Which is best? A proxy forward hides server "Y" from the browser, but if server "X" has limited bandwidth it will use some of it up. The extra step will also be marginally slower. However, a redirect requires the browser to make a second request of a new server, and server "Y" will not be transparent to the browser.

It works like this - your system (in the imserve.com domain in the example shown here) contacts its DNS server, which knows about DNS servers for its parent and child domains. So it can ask the .com server, which can ask the root server, which can ask .net, which can ask .wellho.net ... and the IP address then gets passed back doen the chain. Having completed that shenanigans, the original machine caches the IP address to save it the bother next time, and uses the IP address directly.