why do some websites not have www

A normal Web site has a URL that looks like this: http://www. howstuffworks. com. You may have noticed that on many sites, the www part is not required. You can just as easily use
http://howstuffworks. com to get to HowStuffWorks. There are other sites that have extra layers of naming, such as http://www. delphion. com and http://journal. iftech. com, that seem to use a different word besides www to reference different Web sites. Another common thing you see is a name like ftp. microsoft. com, used either with the FTP command or as a URL ( ftp://ftp. microsoft. com ) in a browser.


If you have read the article, then you know about name servers and IP addresses. A translates a name to an. When you type a URL like http://www. howstuffworks. com into your browser, the browser contacts its default name server and asks, Have you ever heard of www. howstuffworks. com? If this is the first time the name server has heard of www. howstuffworks. com, it finds the. com name server and asks if it knows of the name server handling howstuffworks. com. If so, your name server connects to the name server for howstuffworks. com and asks it about www. howstuffworks. com.


If the HowStuffWorks name server has a listing for the www prefix, it returns the IP address for www. howstuffworks. com and your browser connects to that IP address. The network administrator for the domain howstuffworks. com is in charge of mapping the names in the howstuffworks. com domain to specific machines and their IP addresses. In many large companies, there will be different machines (with different IP addresses) handling WWW, FTP, Telnet and other traffic. On smaller sites, the same machine can handle everything. The network administrator makes a list of names and IP addresses, like this: The] administrator can put anything in that list, because the name servers don't care.


The administrator could put in scooby. howstuffworks. com, scooby. doo. howstuffworks. com and scooby. dooby. doo. howstuffworks. com, and when someone types in those names the name server will return the IP addresses associated with them. In the case of Web sites that happen to work without the www prefix, it simply means that the administrator has decided that if there is no prefix, the IP address returned should be the IP address for the Web server.


For more information, check out the links on the next page. There are several reasons, here are some: 1) The person wanted it this way on purpose People use DNS for many things, not only the web. They may need the main dns name for some other service that is more important to them. 2) Misconfigured dns servers If someone does a lookup of www to your dns server, your DNS server would need to resolve it. 3) Misconfigured web servers A web server can host many different web sites. It distinguishes which site you want via the Host header. You need to specify which host names you want to be used for your website. 4) Website optimization It is better to not handle both, but to forward one with a moved permanently http status code.


That way the 2 addresses won't compete for inbound link ranks. 5) Cookies To avoid problems with cookies not being sent back by the browser. This can also be solved with the moved permanently http status code. 6) Client side browser caching Web browsers may not cache an image if you make a request to www and another without. This can also be solved with the moved permanently http status code.