In a recent update to the iOS Remote Desktop client (8.1.0 and above) you receive the following error when connecting using a Remote Desktop Gateway: Can’t connect to the Remote Desktop Gateway. Contact your network administrator for assistance. (Error code: 0x03000008)
Confirmed on the Remote Desktop Services blog here.
1. Review the TerminalServices-Gateway operational event log on the Remote Desktop Gateway server and look for EventID 301 which states: The user “DOMAIN\user”, on client computer “188.8.131.52”, did not meet resource authorization policy requirements and was therefore not authorized to resource “172.17.50.10”. The following error occurred: “23002”.
The resource IP should be one of your RDS servers, note healthy connections to the Gateway should (typically) specify the FQDN of the RDS server it is trying to connect to: The user “Domain\user”, on client computer “184.108.40.206”, met resource authorization policy requirements and was therefore authorized to connect to resource “RDS-NY-2.domain.co.uk“.
2. Open the RD Gateway Manager MMC on your Gateway server, go to Policies, Resource Authorization Policies (RAP) and review the policy you have configured for your company- note the locally stored computer group used.
3. Choose Manage locally stored computer groups from the right hand side, select the group used in the policy and select properties.
4. Add the IP for each of the RDS servers in the farm (keep hostname and FQDN if present).
Once this is complete it should resolve the issue. Review the TerminalServices-Gateway operational event log and you should now see: The user “DOMAIN\user”, on client computer “220.127.116.11”, met resource authorization policy requirements and was therefore authorized to connect to resource “172.17.50.10”.
This issue/bug/feature is still present in the Remote Desktop iOS application version 8.1.5 from 29th October.