Using Azure internal load balancer (ILB) for Sql Reporting Services

Question

I am attempting to implement a scale-out SSRS deployment using the Azure ILB feature. I have created 2 Sql Reporting servers using the azure images and have created a ILB endpoint on both servers.  I am then attempting to access the servers via the
ILB from my .Net web application.  I can access the report server from my browser and am prompted for credentials using forms authentication.  there is no issue accessing the reports from a browser however my web application cannot access the reports
and returns a 500 error.  I have a hunch this is due to an authentication issue due to invalid kerberos proxy authentication.
Does anyone have any information regarding the possible authentication mechanisms that are supported using Azure ILB?  

Answer 1

Thanks for the response Swallow0417, but as I stated I already had configured this to work in a browser.  I should have mentioned that I already had set the machine key and altered the rsreportserver.config file as mentioned in
https://msdn.microsoft.com/en-us/library/cc281307.aspx.
It turns out this was due to the extended data validation that was introduced in SQL 2014. 
This page led me to alter rsreportserver.config so that:
<RSWindowsExtendedProtectionLevel>Off</RSWindowsExtendedProtectionLevel>
<RSWindowsExtendedProtectionScenario>Any</RSWindowsExtendedProtectionScenario>
After restarting the report server service my application now can make the requests for the reports successfully.  I'll provide the other steps I took to hopefully help someone else in the future:
1. Create 2 or more SQL servers in an Azure availability group on the same service in a Reports server scale out deployment.  The SSRS Service account must be a domain account or it will not work
2. Create an Azure ILB using powershell and add the endpoints on your http(s) ports on the server in step 1. I also set the endpoint IdleTimeoutInMinutes to 30 on both endpoints as it seemed like there was some possible timeout issues. the endpoint MUST
also have DirectServerReturn Set to $true 
3. disable the loopbackcheck see method 2 here
http://support.microsoft.com/kb/896861
create a DWORD registry key value 1,
DisableLoopbackCheck,
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
4. Configure View state validation by setting an identical machine key on all servers behind the azure ILB
5. Create a Host record in your AD DNS for the Azure ILB IP Address. 
6. configure hostname
and URLRoot in rsreportserver.config - see
https://msdn.microsoft.com/en-us/library/cc281307.aspx
Setting the hostname tag breaks the report manager url. It is only
required to set the URLRoot tag. I do not think it is required in this configurtaion only for Windows
NLB
6. Configure the authentication method in rsreportserver.conig
  <RSWindowsExtendedProtectionLevel>Off</RSWindowsExtendedProtectionLevel>
  <RSWindowsExtendedProtectionScenario>Any</RSWindowsExtendedProtectionScenario>