Two domains pointing at the same site

[chesty]

Some weeks ago I hosted a web site with a domain of carpingaround.co.uk. Google has crawled the site and successfully indexed this domain. Soon after I realized that carpingaround.co.uk is not descriptive of what the site is about so I purchased uk-carp-forum.co.uk that points to the same site/content as carpingaround.co.uk. Google will not index uk-carp-forum.co.uk and I am thinking the reason is, because it knows that both domains are the same site.
Ideally, uk-carp-forum.co.uk needs to be the primary address that is indexed on google with carpingaround.co.uk pointing to it.

I have a web forwarding option within the configuration of 123-reg.co.uk who manage my domain names - should I make carpingaround.co.uk point to uk-carp-forum.co.uk using their web forwarding feature or will google still see this as duplicate content. At the moment both DNS records for both domains are simply pointing to a web server.

Hopefully the above is clear...

Thanks in advance..
Paul

[sae]

I usually use web forwarding because it's much easier, however regardless of which method you choose I don't think google will index both pages.

[chesty]

I think i have worked it out.
I am doing a 301 redirect from old domain to new domain.