How does web sites know how to route

Hi there

Could anyone please explain how routing to a website works?

I basically need to know what happens when a site is requested by a web
browser in one country, when the site is hosted in another. For the sake of
the example, say the site is in the United Kingdom and the visitor is in
South Africa.

The way I currently understand it:

1. My browser interrogates my IP settings and finds a DNS server.
2. The DNS server "traverses" until it finds a DNS server with the
requested site name, and converst this to an IP address.
3. My Computer connects to the other IP adddress.

The actual question (excuse the long intro):

Why do some sites first go through the USA and then only to the UK (Is it a
routing or a DNS problem)?

Why do some sites have more and other less "hops" to the actual www server?

any help will be much appreciated.

TYIA

P Smit

 

Easy answer....EVERY web site ahs a unique IP address, yes even
www.yahoo.com is in reality http://216.109.117.106/ and a few others.
A router just sends the info to a central point that then converts the
name into an ip address and then sends it to the correct place.

 

Each hop is from one Internet router to another. The "goal" of a
router is to pass on a packet to another router that is "closer" to the
final destination.

The DNS server only translates URLs into IP addresses. Your DNS server
need not be anywhere near your site. A DNS server broadcasts your DNS
information throughout the Internet.

Finding a route involves making trade-offs. Perhaps the logical next
hop from the current router is to a router that currently is busy.
Maybe a closer router (in number of hops, for example) has a slower
link to the current router. The actual algorithm is unimportant
because it may change, and the results will change as traffic patterns
change and as equipment is removed or added. The packets seek a "best"
path to their destination. (I am not an expert on Internet routing
algorithms, anyway.)

Why go from S.Africa to U.K through U.S.? Probably the connections
from S. Africa to U.S. are fast as are those from U.S. to U.K. Compare
to going to Egypt, then to U.K., for example.

You probably already know about traceroute (Windows version = tracert;
run from command prompt window). It tells you the route and the time
per hop so you know how efficiently you can get to a given site.