'Page not found' during DNS propagation

8 times in 8 attempts the site has been down

[Hoojie]

We want to move our site to a new host. My colleagues, their techies and the hosting company say that at no time during the DNS update will the site be unavailable. Surfers will either see the old web space or the new web space, but nobody will get 'Page not found.'

Having done a thorough search of Webmaster World, I cannot find a single post that mentions my problem. You see, I have migrated sites in the past and migrated parked domains to a web space - I think eight times in total. On every single occasion, I got 'Page not found' shortly after I changed the name servers at my registrar until DNS resolved 18 to 30 hours later.

This is not the way DNS is suposed to work? I wonder if the problem lies with my registrant. I use UKreg.com and they don't have any support or Contact Us. I mean they do have the feature on the site but there's never anybody home. That's no problem because I don't usually experience trouble.

Why could this be? Tomorrow we are scheduled to set up redirects, backup the site to the new space and change the DNS. Every fibre in my being says "No, you will be off the air for a day". Everybody else is saying "Nonsense, that does not happen."

Why could it be different 9th time around? Has anybody got any ideas? Please?

[treeline]

This usually works very smoothly, if done carefully. Since the site already exists, every system already has a DNS entry for it. Those that don't update will keep sending traffic to the old host. When they do update the traffic will go the the new host. For about 2 days some traffic will go BOTH places.

Step 1. Keep everything on the existing host exactly as is. Do not change, do not cancel, do not forward. Pretend this will conitinue to be your host forever.

Step 2. Have the new host set up to work exactly like the old one.

Step 3. Test the new host, ensure it works properly.

Step 4. Keep the old host working, do not change anything.

Step 5. Change the DNS settings at the registrar from old to new.

Step 6. Keep the old host working, do not change anything.

Step 7. Test that the new host is working as expected.

Step 8. Keep the old host working, do not change anything.

Step 9. Track traffic logs at both hosts, call several widely scattered friends and have them visit your site and report on status.

Step 10. Keep the old host working, do not change anything.

Step 11. After at least a week, if all has gone really well and you're really happy, you can let the old host wither.

This strategy also allows a quick graceful switch back to the old host if Murphy strikes. If there's a problem, it usually either you cancel the old host too soon, or the new host wasn't actually quite ready when you jumped. Pay special attention to steps 1,4,6,8&10 and you're unlikely to go wrong.

Good luck. This can go just fine.

[Hoojie]

Thank you, Treeline. It went fine in the end. I realised what I had done wrong on previous attempts.

Your advice was spot on.