Google DNS info

switched servers but still likes old IP

[Rugles]

I am sure this has been asked many times in the past, in fact I have read a discussion recently.

We switched servers and have a new IP address. I wisely left the complete site on the old server for the next few weeks. The googlebot is hitting the old server.

How often does google change its DNS information?

[dmorison]

How often does google change its DNS information?

I'm confident that Google do not cache DNS for any longer than specified in TTL (time to live) for your DNS records.

It would be silly of them to anyway; they want to seach the Internet "asis", and that means using up to date DNS all the time. They'll follow the rules.

[Mohamed_E]

I'm confident that Google do not cache DNS for any longer than specified in TTL (time to live) for your DNS records.

Until several months ago they were notorious for caching DNS records far longer than the TTL specified. Not sure that I disagree with that strategy completely; there are very many hostmasters who set a ridiculously short TTLs on essential unchanging addresses.

From what I understand they are now much better, but I have not heard that they actually go so far as to respect the published TTL.

[plasma]

Until several months ago they were notorious for caching DNS records far longer than the TTL specified

Yup, same here.
For one of our customers google needed more than a month to realize the new IP.

[dmorison]

I'm disappointed in Google if this is the case. TTL is there for good reason; even if some admin's do make it too short.

[claus]

Afaik, the specified TTL is far too optimistic - i agree that it's the proper thing to do, but Google seem to disagree with me, unfortunately. I guess they have some reasons for caching longer and hence introducing a lag time.

/claus

[Romeo]

... you didn't tell what happend to your old DNS, so perhaps the following does not apply to your situation:
It could be wise to ensure on your part, that all old DNS zone information is effectively scratched. You may leave the old server running, but should have deleted all old authoritative DNS zone info pointing to it.
I have seen and suffered myself from bizarre cacheing situations where new visitors found a moved new address immediately and as expected, but for recurring users old existing caches partly remained active because they always found the former old original DNS source serving them wrong old information again and again. Scratch the old zone entries to enforce new lookups after TTL.
Whether this may clear any special situation with google cacheing or not, it may be advisable to do anyway.

Regards,
R.

[Rugles]

Everything was done properly. Google is still hitting the old server after more than 48 hours after the new server started taking traffic. They are the only ones.

It appears that I followed the correct course of action, by keeping the web on the old server.

I will keep an eye open and report back as to when google starts on the new server.

[hazardtomyself]

About 4 months ago I changed a PR 4 site to a new server/IP and it took Google roughly 2-3 weeks to start spidering the new IP. I know this because I left the old site up...Geez, I think it's still up...and I changed the title tag on the home page of the new IP and I did not see the new title tag in the results for roughly 2-3 weeks. It will happen though.

[Rugles]

I will bore you all with a new development.

Now the googlebot is hitting both servers. I am going assume that it takes time for the DNS information to propagate throughout google's entire network.

[Mohamed_E]

Now the googlebot is hitting both servers.

When did the DNS change take place, and when did Gbot start hitting the new server? This would give us some hard numbers to replace the phrase "Google is getting better at updating DNS".

[Lightfoot]

Last year it took months (literally) for Google to realise my site was on a new server - this caused real problems as I had no access to the old. But I changed server again a few weeks ago and Google crawled the new one within a few days. I think they have tightened up on this

(which is a good job, because my original, incompetent hosts deleted my site from the old server shortly after I moved without my express permission! But there again....there may be some advantage to this. There's anecdotal evidence that if the site disappears it might spur Google to search for the new location, but risky.)

[Rugles]

Ok, here is the hard information on the change.

All times are EST.

The first hit on the new server was at 5:01 pm on Oct 6th.

Googlebot (from the 64.xxx.xxx.xxx range) started its first serious crawl at 12:30 am Oct 9.

During this whole time googlebot was aggresively crawing the old server and it still continues. Googlebot did hit the new server 4 times over two days before the first serious crawl started.

All the other major crawlers have moved to the new server.

[twilight47]

Were going to be in IP change boat soon. I undertand the need to keep the site up in both places. My question is what kind of PR and ranking hit will we take in the SERPs?

[Lightfoot]

You shouldn't get any ranking or PR hit at all if both sites are identical on both the old and the new server. Once you're confident Googlebot and other engines are happily crawling the new server (you can leave a slight difference to check in the cache - e.g. a full stop somewhere), delete the old site off the old server.

[Mohamed_E]

The first hit on the new server was at 5:01 pm on Oct 6th.

Googlebot (from the 64.xxx.xxx.xxx range) started its first serious crawl at 12:30 am Oct 9.

Many thanks for the information, Rugles!

Unfortunately 12:30 AM Oct 9 is slightly ambiguous, I take it to mean 30 minutes after midnight?

Assuming the DNS change took place on Oct 6 around noon that means about 60 hours for GGbot to get to the new IP. Given that "the word on the street" a year or so ago was that it could take up to six weeks, that is quite an improvement.

[Rugles]

Mohamed_E

Yes, it does mean slightly after midnight on the east coast of north america.

I just checked and the Fast crawler has hit both servers today as well. So I take back what I said earlier concerning google being the only one with the slow response to a DNS change.

[Rugles]

It appears that google has settled on the new server and IP address.

8 days in total in think.

[turk182]

Eleven days ago we changed our IP, and today November 26th Google is still spidering the old server. Nevertheless I've set up a site redirection, so Google can see the new server. What puzzles me most is that sometimes googlebot enters the new server directly, and sometines it comes from the old server thanks to the redirection. Is it possible that Google updates the DNS at different times in different crawling servers?