Hello there,
We've built Excel add-in on .Net framework 3.5 that utilizes remote API for data processing.
Everything seems works as expected however one of our corporate customers has reported that our add-in doesn't work within their corporate network.
During few rounds of debug we noticed that add-in can't resolve DNS name by calling System.Net.Dns.GetHostAddresses(String hostNameOrAddress) method. And reports following error: This is usually a temporary error during hostname resolution and means that the local server did not receive a response from an authoritative server.
Customer has strict security environment, so they setup NAT server and transfer their internal IP to our remote one where is API located. On client machine they have added new line to the host file to move the users from our host name to their NAT server. Like shown below:
192.87.56.89 api.somenetwork.com
What is interesting that Internet Explorer is resolving name correctly and can access remote API, however .Net application (Excel add-in) doesn't.
Can someone suggest where to dig in order to solve or at least understand the problem.
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Thanks in advance,
George