How long should an old site redirecting to a new site remain activated on a server?

[jwanner]

Once I switch a site to a new domain (with links to corresponding/relative pages), will I have to keep the old site live forever for those links to work, or how long should I wait before I inactivate the old site on our server?

[Andy.Drinkwater]

Not at all - on the new site, setup a list of pages to be redirected (301) to corresponding pages on the new domain and make sure you advise Google through Webmaster Tools that the site has moved.

However, don't turn everything off on the old server until you have confirmed all is working on the new one.

-Andy

[EGOL]

Mine will still be there when I attend my funeral.

[Stramark]

Google has an extremely long memory for old URL's being live and linking. It is anoying realy.

Links from websites to your old domain are still there, you want to hold on to that value. Thus you will keep the old domain redirected. You do not need a server for that, just the domain pointing to the server and redirecting it on your server. Your web hosting support can help you with that (if not, switch to wp engine)

[TheeDigital]

301 redirects are called permanent, but that's not really the case. They are permanent only as long as they are in place. If you want to see this, do everything as Andy said and then remove the redirect. You'll notice your traffic drop and when you put the redirects back the traffic will recover. Go ahead and do this every year and you'll see that each time it drops. We've dealt with drops that happened from domains that haven't been active in over 5 years, so as EGOL alluded to, keep them forever.