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14-02-2002, 01:03 AM
Evening All.

I noticed a little while ago that sometimes links had the 'www.' part missing, so I started experimenting with just keying in the rest of the address for non-US sites (for .com sites I use Ctrl+Enter).

It works most of the time, but not always.

My question is this:
When it does work without the 'www.', is it because the owner of the site has registered two names, or is the 'www.' prefixed automatically in most cases?

If the latter, why doesn't it always work?

Thanks,

John.

14-02-2002, 03:02 AM
What browser are you using as NS6 will do a search and may come up with the right site.

14-02-2002, 10:21 AM
Hi Mike

I've got IE 5.5 SP2.

IE also does a search if nothing is found, and often comes up with the right guess.

I'm curious about what's happening at the server side, so I can make an educated guess whether 'www.' is going to be needed or not.

Cheers

John.

14-02-2002, 11:46 AM
Short answer: DNS records. Whenever you type in a domain. EG www.pcworld.com your machine goes to a DNS server to find the IP address of the machine that the service is hosted on. Sometimes company's also put the same record in for the domain and the www prefix meaning that you can put either in.

14-02-2002, 01:03 PM
There are a mixture of reasons for this.

If the published name is www.thing2.thing2.top, all parts are strictly necessary. The 'top' is the top level (least specific) domain. That is owned by the domain name issuing organisations. These include 'com', 'gov', 'edu', etc in the US. The two letter domains such as 'nz', 'uk', 'tv', 'ca', (and even 'us') denote countries. As we go backwards in the name, the addressing becomes more specific. 'co' is the commercial domain in NZ. 'ac' is the Academic Community in the UK and NZ.
there may be company names, or university names in the next position to the left. This can be subdivided more and more (look at some of the names of IBM hosts).

An example: nix.tmk.auckland.ac.nz . The 'nix' is the hostname the most specific part of a name -- can be 'the' name of a computer -- a 'host' or one of several names for a 'multihosting' computer. Different names as registered with a Domain name server may have different IP address , or differetnt asigned port numbers(for different protocols -- FTP, HTTP, Telnet, etc).

That host is located at the Tamaki campus of Auckland university of the academic community in NZ.

Some web servers have the hostname 'www'. Some do not. If you omit the 'www'
part of the name, you will probably still be connected. What happens is:
(1) Your browser looks to see if it has the page URL you give it cached (stored on your disk). If it has, it displays it.
(2) If not it sends the URL as you have given it to your ISP's nameserver. If it has that name cached, it returns the IP address to your browser which then send a request for the page.
(3) If it has not got the address, it asks its nameserver. If it has it, it is relayed to you. If not, that nameserver asks its nameserver ... This continues up to the main toplevel nameservers if necessary.

If the name can not be found in that chain, your browser tries again, putting 'www.' in front of the name if you have not put it there. It may put '.com' at the end if there is not top level domain identifier in the given name.

This also happens if you do not put a '/' at the end of a name ... The browser asks first without, then asks again after adding that.

It is quickest to give the full address ...

If I am in a crowded room with John, I might yell 'John' to get his attention. There might be a bit of competition. If I yell 'Calvert', possibly less.
But 'John Calvert' gets the address sorted first time.

14-02-2002, 11:03 PM
Thanks to all for the detailed answers.