I use the BlueCoat ProxyClient filter in a small office network (< 50 computers). We have it set for category based filtering and it works perfectly on almost all sites. However, sometimes, we have a site that
- Even if it's in an allowed category
- Even if we add it explicitly to a whitelist
- Even though we can navigate to it in a browser,
- It still does not function properly unless we add it to the "SSL intercept bypass" list.
What does this "bypass" actually do and why is it necessary?
- We installed Visual Studio 2015 Community on one of our computers
- When we tried to update our license using our MS account, we got the message "Failed to update license".
- Using Fiddler we found that VS was trying to access
https://app.vssps.visualstudio.com. That's flagged as Technology/Internet by BlueCoat which is on our allowed category list.
- We added it to our explicit whitelist and it still didn't help.
- We enabled the HTTPS decrypt setting in Fiddler and found that it was sending a lot of requests to
Authenticateheader that looked valid, but the response was coming back as
401 Not Authenticated.
- We finally added
app.vssps.visualstudio.comto the SSL bypass list and it suddenly started working.