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In the past Google seemd to have a very long lasting (weeks!) DNS cache, so I always made sure that the site was also reachable under the old IP. This doesn't seem possible now.
Does Google still have this long lasting cache? If so, is there a way to notify them of the change?
What's the best way to deal with an IP change?
I'll post back here if we encounter any probs over the next few days.
Marra
I've just checked the site we moved.
The home page has already been found on the new server. (less than 48 hours)
Hopefully the rest will follow.
Marra
My provider just told me that my server is being moved and will get a new IP address.
Assuming you have a unique IP#... see if you can get your host to put up a duplicate of your site on the new server before the old server goes offline, and then to point the DNS to the new IP before taking the old one down (and to keep that arrangement up for at least a few days, if not longer).
Migration should then take between 24-72 hours, and in my experience will be seamless. Google and everyone else will see only one IP address or another. I recently made such a move, and Google had the "new" site in its index in about 24 hours.
I suggest you change the capitalization of one letter in your default page title so you can quickly tell which site Google has indexed. Yahoo took a little longer than a week, also apparently seamless.
So, depending on the machine the crawler is, the last time that machine queried your DNS and your refresh rates, I'm speculating that Google is not caching the DNS addresses any more, like it used to.
>> What's the best way to deal with an IP change?
Here's how we rolled the DNS over.
1) Setup our own dns servers dns1.server.com and dns2.server.com -- 48 hours to propagate the IP addresses to verisign / NSI. Used [verisign.com...] to verify that the IP addresses were propagated.
2) Changed the DNS server on record at the registrar to DNS1 and DNS2 which were recorded above. Used dnsstuff.com and dnsreport.com to verify that these had propagated and setup correctly and all the gltd servers were reporting them correctly. Another 24-48 hours.
3) Copied all the files / databases over the new server (on a dedicated IP) and ensured everything was working properly.
4) Switched the IP address to the new server on dns1 and dns2. Watched traffic hit both sites for a day or two. Once traffic stops hitting the old site (i.e. DNS is fully propagated) we'll delete it.
[edited by: shri at 4:16 am (utc) on July 26, 2004]
