Can't access certain pages only from the customer's office.
This problem has been bugging us for two years:
I have a dedicated server with Server Matrix and there are more than 30 websites in it.
Earlier, we created a website for a customer in London and also have this website hosted in our ded. server. We assigned a separate IP address for this website. The domain is not hosted by us as the customer wanted to manage their emails by themselves. As such, the customer instructed their domain registrar to point the domain to this IP address.
The problem is that the customer sometimes failed to access certain pages (both HTML and scripts, even after clicking REFRESH on the browser). Everytime when I was told so, I would quickly check it. I also get my sister (in London, same as the customer's city) and a few friends in different countries to access the pages/scripts which the customer said he could not access. And we all have no problems with it.
We believe that it has something to do with the proxy server in the customer's office. But we are not sure what exactly is the cause. I should be much grateful if anyone could help or give some suggestions.
I doubt they would have had DNS entries cached for 2 years ...
Who is your customers ISP? Do they have an internal router/cache/firewall of some sort? Can they ping the server? Does your web application use any other port that 80? Have they tried using another web browser as sometimes Internet Explorer gets caught up with security policies?
█ Dan Kitchen | Technical Director | Razorblue
█ ddi: (+44) (0)1748 900 680 | e: [email protected]
█ UK Intensive Managed Hosting, Clusters and Colocation.
█ HP Servers, Cisco/Juniper Powered BGP Network (AS15692).
It is almost certainly the proxy server. I can just speak for ISAServer since I know that well but you can and may have content rules that are blocking pages with specific words.
For instance have a proxy server filter content based on content type or based on the word "orange". This means that any page with that word would not load. Also sometimes particularly in corporate offices they do a proxy rule to block all then ONLY let specific pages load. The problem with this approach is if you have a page like webhostingtalk and you allow it but don't allow the banner ad location properly or tell it to ignore it, you can get a not found or a login box.
It can be intermittent due to dhcp and perhaps one scope is allowed access but not the other so you sit at one pc it works and on another it doesnt.
Final thing to check is local hosts files. I have done this before tore apart other items looking for the problem and it was simply the old ip was in the local host file.