Last night I switched the DNS information for a domain I manage to point to the new webserver. Because of hardware differences (the pages get built from our inventory database. It builds them at midnight each night, not dynamically on each request) the actual markup is slightly different*, but the text on each page remains the same and each page exists at the same url. So, for example, www.domain.com/somepage.html gets the same information that it did yesterday, just from a new server.

This seemed to go seamlessly, I powered down the old web server this morning, and everything looked fine. I notice today, however, that our rankings on most of our key terms that we focus on has gone down significantly.

My question here is, is there anything obvious that I could have done incorrectly here? If not, have any of you suggestions as to why this may have happened or things I should be looking into?

* - All the markup changes were, in my mind, good ones. There were places before where headers were just bold tags around a paragraph, now they are all h# of the appropriate class. Other, similar "no-brainer" changes were made, but nothing drastic.

Last night I switched the DNS information for a domain I manage to point to the new webserver. Because of hardware differences (the pages get built from our inventory database. It builds them at midnight each night, not dynamically on each request) the actual markup is slightly different*, but the text on each page remains the same and each page exists at the same url. So, for example, <SNIP> gets the same information that it did yesterday, just from a new server.

This seemed to go seamlessly, I powered down the old web server this morning, and everything looked fine. I notice today, however, that our rankings on most of our key terms that we focus on has gone down significantly.

My question here is, is there anything obvious that I could have done incorrectly here? If not, have any of you suggestions as to why this may have happened or things I should be looking into?

* - All the markup changes were, in my mind, good ones. There were places before where headers were just bold tags around a paragraph, now they are all h# of the appropriate class. Other, similar "no-brainer" changes were made, but nothing drastic.

Chances are that the "new" pages haven't been indexed if the move to the new server took place yesterday. If there are differences in the code, do a query and view the the cached version of a page, view it's source and see if the new pages are cached. Keep in mind that you are looking at Google's cached version and that Google's code will be at the top of the page in the cached version of the code. The differences in the code could cause a drop.

When you change ips it is best to leave the old ip live for as long as a few days after the switch so that the new dns setting is picked up across the board. Chances are than any loss due to the server switch will come back within a few days.