Are you still worry about your website has duplicate content issue in search engines. We all know Google hates duplicate contents, waste bandwidth and them indexing power. So Google will filter all duplicate content, sometimes even a penalty will follow.
Now, you can avoid duplicate content issue from beginning. Choose either www domain version or non-www version. Either will work great, but which one will you decide to use, are totally subject to your personal taste.
Simple, setup an "A" DNS record for version you wish not to use to our redirection server IP:
The redirection is instantly, no delay on client side. The redirection is 301 Moved Permanently ( a redirection method will pass any ranking and PageRank in Google terms ), all URL path and all parameters ( the querystring ) will remain unchanged.
Except the default http port 80, our 301 redirect service also handles URLs with difference ports used in all kinds of web servers and software. The URL with port other than 80 will be redirect to default http port 80, and the www will be added or removed accordingly.
HTTP alternate (http_alt), commonly used for Web Proxy and Caching Server, or for running a Web server as a non-root user.
81, 82, 8000, 8001, 8002, 8002, 8008, 8080, 8088, 8090, 8180, 8888, 10080
|591||FileMaker Web Sharing (HTTP Alternate)|
|593||HTTP RPC Ep Map, Remote procedure call over Hypertext Transfer Protocol, often used by Distributed Component Object Model services and Microsoft Exchange Server|
|981||SofaWare Technologies Remote HTTPS management for firewall devices running embedded Check Point FireWall-1 software|
|1080, 1081||Socked Proxy|
|1311||Dell OpenManage HTTPS|
|1920||IBM Tivoli Monitoring Console (HTTPS)|
|3100||HTTP default listen port for Tatsoft|
|3128||Web caches or client connection for Squid|
|4567||Sinatra default HTTP Server Port in development mode|
|4711, 4712||McAfee Web Gateway 7, Default GUI Port HTTP and HTTPS|
|5104||IBM Tivoli Framework NetCOOL/Impact HTTP Service|
|5800||VNC Remote Desktop Protocol, use over HTTP|
|6005||Camfrog Chat, Cam Client, BMC Software Control M/Server—Socket|
|7000||Vuze HTTPS Bittorrent Tracker|
|7001, 7002||BEA WebLogic Server HTTP Server and HTTPS Server|
|8011, 8012, 8013, 8014||HTTP/TCP Symon Communications Event and Query Engine|
|8243, 8280||HTTPS and HTTP listener for Apache Synapse|
|11371||OpenPGP HTTP Key Server|
|16080||Mac OS X Server Web with Performance Cache|
|21001, 21011, 21012, 21021, 21022||AMLFilter amlf-engine-02 default http and https port|
|HTTPS 443||Browser will display a Untrusted Connection waring for the SSL (ssl_error_bad_cert_domain).|
|8081, 8082||These two ports were taken by McAfee Framework Services (FrameworkService.exe), part of McAfee Total Protection for our server. Since we cannot change it, nor leave our IIS Server unprotected, these two ports will not work for now.|
WWW, became the start of a website URL from the beginning of the internet. For any traditional website or business, a website domain start with WWW is more prefer, more decent and legitimate. If your website is mainly for informational purposes, you should choose WWW version for your website domain.
Since recently, the start of the web 2.0 dawn, the website URLs without WWW are starting take over the internet. Almost all newly development web 2.0 websites, social networks are using no-WWW. If you are running a interactive website, choose no-WWW version for your website.
When received a 301 Moved Permanently header, most modern browsers will understand the HTTP-Header and POST the form content to the new location. However, as we found the statement on W3C: "some existing HTTP/1.0 user agents will erroneously change it into a GET request".