I have a website in asp.net, and about 27,000 pages of its are indexed in Google. I want to redirect all the pages of this site to the new site that i have made in the same platform. The problem is, if i started redirecting the pages manually, i.e. for each page it will take months and not possible for me. Could someone help me out of this if some logic can be implemented to sort it out, so that all old pages will be redirected automatically to the particular new dedicated pages.
Asp.net means IIS. There are utilities out there that can do rewrites like mod_rewrite for Apache. You will need to find whatever patterns you can to rewrite from the old system to the new.
In the last platform migration for my day jobis it only took about half a dozen rules to get everything done. The trouble is finding and mapping these out. If that is done you should be almost there.
Without specifics we probably won't be able to help much more.