Serge, you seem to have more intelegance than the person whom sent me this 'know it all response' to an email I sent.
First I sent the following email this morning. The system is still trying to send to everyone as you would expect with 10K+ recipents. Most on yahoo and hotmail that throttle delivery anyway.
"We have sucessfuly moved servers. If you still see that the site is closed when you visit your still hitting the old system. Close yoru browser and try to visit the site again after opening the browser again. If that does not help restart your computer or if you have a home router between you and the internet reset the router.
The issue is your system has cached the IP address of the domain and it has not gotten the new IP thats assocated with the site yet."
Now what I got from a very knowledgeable person back.
"Actually, local computers have nothing to do with that... it's all DNS ...
why would I reset my computer or router?
that's just stupid ...
no offense of course.."
And my response
"On the contrary your PC
will store DNS information for sites it has been to in a cache so it does not have to do a DNS lookup for every single page request. This increases performance. You can unselect this as an option on most browsers. You can also have it clear this cache when you close the browser out. I am very fimular with networking so I was not just talking out my tail pipe when I sent that message. In addition I have experenced it myself where my PC
sees a new IP being assocated with a website yet when the website is visited from the computer you get the old website. A reboot will sometimes fix this if your not attached ot a home router but the home router could itself being doing osme cacheing of DNS information and would then direct the web request to the old IP regardless what a ping might come back with.
I saw this happening first hand last night and a reset of my local router got my browser hitting the new IP. So one only has to reset things IF they are cacheing DNS information for the short term. Over the long term (24 hours or more) the cached information will expire and the caching system will request new information about the site and its IP resolution but if you wish to resolve to a new IP before the existing cache times out you must clear the cache so the system requests new information right away."
Now I dont admit to know everything like this person seems to think they do but I do know about caching of DNS. My gosh if a DNS request was made for every single request to a webserver compaines would need HUGE clusters of servers simply supporting DNS where as reality is that the DNS servers are usually the oldest and least equiped systems as compared to application and database servers in general.
My inital email was an attempt at dumbing down the caching. I will try to remember the /flushdns command as that will be helpful for me in the future.