Hope that someone reading this blog can help me with this problem (or know someone who can). And the story goes like this...
Three users have recently reported being unable to access their Sampa site. They can access pretty much any site on the Internet but not a Sampa site (e.g. http://marcelo.sampasite.com)
Data points:
- Sampa sites (*.sampasite.com) use our own DNS system (on ns1.sampasite.com, 207.115.80.185)
- NSLOOKUP for these users return the correct IP address: 207.115.80.185
- Internet Explorer, on the other hand, cannot reach the site giving a DNS-like error (e.g. “This page cannot be displayed”)
- They can access www.sampa.com (207.115.80.184) which is on the same network, but uses Windows DNS
- Sampa sites don’t have reverse DNS (don’t think this matter)
The problem is that NSLOOKUP works fine, but IE cannot resolve the address (one user tried using Firefox and it didn’t work either). I don’t know if NSLOOKUP uses Microsoft’s DNS Client, or it has its own Socket implementation. I don’t even know where to start this investigation short of asking people to install a network sniffing tool, which is probably way beyond these users’ ability.
I want to write some C++ debugging tool that I can give to these users to help them identify the problem, but I’m not sure where to start.
Anyone has any idea of what else I can investigate to get to the bottom of this issue? Could this be some anti-phishing tool problem?
I'm the Co-founder & CTO of 
