Domain name forwarding

Is it classed as duplicate? plz help

[chrisandsarah]

I have a fairly popular site e.g mainsite.COM
I have another similiar domain name registered ,e.g mainsite.CO.UK and have it pointing (using web forwarding) to mainsite.COM which is hosted and has lots of pages, lots of content.

I have recently noticed that the secondary domain name - mainsite.CO.UK is listed in yahoo and google and when i go there it frames the content of mainsite.COM.

Will this be looked on as duplicate content/spam etc? I dont want to get mainstie.com penalised or anything (though i fear this is too late with yahoo)

Should i go set the .CO.UK site to 'no web forwarding' so that when typed into a browser it just goes to the company i reg'd with holding page?

ANd is it possible for me to remove it (the .co.uk one) from google and yahoo somehow?

Any advice/info is much appreciated. I'm really worried

[tedster]

The phrase "domain forwarding" is not a technical description and many businesses use it to describe different things...most commonly a 302 redirect (moved temporarily) which is NOT the best practice. A 301 redirect (moved permanently) is the best practice.

You can check you url's here to see what the server headers are:
[searchengineworld.com...]

Sometimes the phrase "domain forwarding" is used to describe simple framing , which is not a search engine indexing issue as far as I know. But it does have all the usability issues that frames have -- bookmarking is problematic, the location bar stays the same when pages changes and so on.

So as I said earlier, a 301 redirect is the best practice if you want more than one url to take visitors to the same content.

[janemc]

I have a similar situation: a single physical site with a domain name (.com)which we've used for 4 years and a second domain name (.fr)which we've used for 10 years.
They are registered with different domain name companies. For the last few years, the .fr has been pointing to the .com site. When I check the server header for them, both are 200. I have recently learned about the 301 redirect, and it seems I should be using that. To avoid duplicate content issues.
I can get access to the htaccess file on the .com site, but it seems to me that I need to do the 301 from the .fr side. Do I need to contact the domain name company? Or can I do something myself? This may be a naive question, but not being very technical, I would be grateful for some advice. Thank you in advance.