Hey, the basic answer here is with HTTP 301 redirections from the original pages to the new page.
Rather than just knowing the cryptic name it helps to understand what is going on behind the scenes a little and why this works. When a page is requested on your site the web server returns a HTTP status code. For a standard page request this is 200 OK and for missing pages a 400 Page Not Found response is returned. There are many other responses but the one we are interested in is for indicating a permanent redirection from the resource on Site A to a resource on Site B and this is a 301 Permanent Redirection.
This provides a range of benefits for users and the search engines
- a user visiting the old site from a search engine result listing is transported to the new resource
- a search engine visiting the link is informed that this resource has moved to a new location and the new page is given
- the page rank and value from any inbound links is forwarded to the new page (not all but most)
So, in this case the 301 redirect provides a complete solution to your problem. It updates and redirects users without requiring anything from them and it allows the search engine to update their records and start concentrating on your new site.
Note
There are a few things to take into consideration here to make sure this works well
- You need to manually redirect page A to page B so there maybe a fair bit of work involved for a larger site
- The redirections may need to be in place for a good while and if you generate a lot of direct traffic - keep an eye on the indexation and web logs for the old site to decide when you can kill it dead
Ultimately, you want the old site to remain in place, redirecting requests until it no longer receives any traffic (or such a low level that it is practical to remove it). If you do get a lot of direct traffic, be sure to update people so they can update their records.
Approach
Which brings us to the technology and approach required. I see you are using .Net aspx pages which is not really my bag but I can give you an overview of the options. You also seem to have wildly different page rules so a cute solution that just dynamically changes the domain but keeps the page the same is not going to work here (sorry).
- Page Level Redirects: add code to the individual pages to redirect to the new page
- Add redirection rules to the global.asax config file
- Create rewrites in the IIS GUI
Beyond the rewrites
An oft overlooked strategy with 301's is to get them done and then really concentrate on the new site. Start building links, try to repoint some of your high quality older links to the new site and start building and promoting new content to get some really high quality links to the new site. All of these strategies will bolster the new site and help it replace the old site as quickly as possible.
Summary
If you have a big site, manually rewriting all the URL's to the their counterparts on the new site is going to be a bit of a job but one that is worth doing. If you want to prioritise the job look at your most popular pages in your analytics and this gives you a plan of attack. Once you have created specific rules for this you can create a catch all rule to redirect all remaining pages to the sites homepage.
That, pretty much covers it. If we have a windows server / IIS / asp.net guru here who can dive in and fill you in on the specifics of the actual syntax and approach then you should be good to go.
Shout if you have any questions.
Marcus