Network error has been detected

Discussion in 'Parallels Remote Application Server' started by MichaelS24, Nov 16, 2016.

  1. MichaelS24

    MichaelS24 Bit poster

    Messages:
    7
    I have a very simple sandbox environment that I have been testing V15.5 in. It consists of a single gateway, publishing agent, and RDS host. I am having no success using the "Gateway SSL Mode" with the Parallels client. What is strange is that I can access the HTML5 interface and successfully launch applications, but just not from the client.

    I receive the following error on the Mac OS X client:

    The connection was ended because of a network error. Please try connecting to the remote computer again.
    [The operation couldn't be completed. (NetworkDomain error 2.)]
     
  2. MichaelS24

    MichaelS24 Bit poster

    Messages:
    7
    This particular bug about drove me insane (and I will call it a bug). When I created this simple environment and added the RDS host, I only typed in the short name (not the FQDN). I ran a number of wireshark captures on the gateway box before I finally spotted it. Although the "Gateway" configured was specified as "V4 only", when the application was being launched I saw in the capture an AAAA (Ipv6) lookup for the RDS host, which obviously it didn't find. It then fell back to a Netbios name query. I manually added the RDS host into the local "lmhosts." file on the gateway and it finally started working.

    Next, I went back into the console and put in the FQDN of the RDS host and did another capture. I still see the AAAA lookup, but it is then followed by a standard DNS A record query.
     
  3. PaulChristopher@Parallels

    PaulChristopher@Parallels Product Expert Staff Member

    Messages:
    3,158
    Hello MichaelS24, this error occurred because of either Remote Desktop services are not running on Terminal server or Terminal Server Agent Port does not match system RDP port.
    To fix this issue, please follow the instructions mentioned below:

    1. On Terminal server open services.msc applet and start Remote Desktop Services service.
    2. On Terminal server check the following Windows Registry entry:

    HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\TerminalServer\WinStations\RDP Tcp\PortNumber

    3. Make sure its decimal value matches the port specified in Parallels Remote Application Server console > Farm > Terminal Servers > Terminal server properties > Agent Settings > Port.
    NOTE: if system RDP port has been recently changed on Terminal server, restart of Remote Desktop Services service is required.
     
  4. MichaelS24

    MichaelS24 Bit poster

    Messages:
    7
    In this particular instance that is not the case. Please see my technical explanation of this bug with the v15.5 code base. I spent a great deal of time combing through Wireshark captures before I figured out what was happening. If the RDS host is NOT fully qualified within the configuration, the gateway machine (separate server) does only a AAAA (IPv6) lookup of the RDS host (which fails) and then follows it with a NetBIOS lookup (which also fails). I finally figured this out by adding the IP/Host into the old LMHOSTS. file on the gateway server. However, once you put the FQDN of the RDS host into the configuration, the gateway still does a AAAA (IPv6) lookup but then follows it by a DNS query. Even though the gateway is specified in the configuration as V4 only.
     

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