We have just recently upgraded our site ColdFusion 9. We are also on IIS 6. Before we performed the upgrade, we switched IP addresses between the production server and a clone server. Traffic would temporarily go to the clone server while we performed the upgrade on the production server. Once the upgrade was done. We wanted to revert the IP addresses back so traffic can start going to the production server. Strangely visitors were not able to reach the site on the production server. Our system administrator had thoroughly and repeatedly verified that the IP address and DNS settings are correct as well as the settings on IIS management. His conclusion is that the upgrade of ColdFusion has something to do with this issue.
Has anybody ever come across such an issue? If so, how did you get around it? Thanks.
This is not a ColdFusion issue and I'm surprised that your "system adminstrator" is even suggesting that. DNS resolution has nothing to do with ColdFusion.
Have your system administrator do a "tracert" to your server from one of the affected machines. This should show you/him where the traffic is being mis-routed.
Please report back with your findings.