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UDP/TCP Port Forwarding not working

We have a new FLEX-6400 (non-M) set up at the Arizona Science Center, callsign W7ASC. We are trying to configure the transceiver for remote operation; however, we are having trouble getting port forwarding working.

Under SmartLink, we are able to configure the transceiver for Static IP and set port forwarding for UDP 22014 => 4993 and SCP 21015 => 4994. We are successful in registering the transceiver when we press the PTT, however when testing communications, the ICON button turns RED.

Here is a picture of how we have our router configured. Any port packet designed for the Flex IP is forwarded to the static IP, no matter what the port number is.

Any help would be appreciated.

Thomas NE7X...


  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

    I created a support ticket for this.

  • Mark Adams
    Mark Adams Member ✭✭

    I'd be interested to know the outcome of this ticket. In October I installed my 6500 in an effort to get the UBARC on the air for the Collegiate Challenge. Turns out that the real challenge was getting it connected so we could use it! I'm an engineer at the University at Buffalo and pretty much have rock-star access to the facilities here. The rig was installed in a comm closet right below the elevator room and roof, a short 50' coax run to the 80M OCF antenna. On my iPad, computer, or phone I could see the radio in the connection list, but could not connect. The slice would appear on the screen for a 1/2 second and disappear.

    The guy who runs IT ops, related to the ports, connections, firewalls, etc. told me that the Flex needed to use a port that was blocked by our firewall and that the only way to get the port open was if a Dean or VP would apply for an exception. The IT is a ham and he could not find a work-around.

    The project is now in limbo and my Flex is back in my shack.


    Mark K2QO


  • Thomas NE7X
    Thomas NE7X Member ✭✭

    SmartLink is designed to operate in a NAT environment since that is by far the most common residential network configuration. Therefore SmartLink is designed to do a NAT port forward translation. SmartLink discovers the public IP address assigned to the WAN interface on the border router that is performing the NAT and the port forwarding.

      If the radio has a public IP address, and if there are two straight one-to-one firewall pass rules to:

      allow *.* on 4993/UDP to access the IP address of the radio on port 4993/UDP

    allow *.* on 4994/TCP to access the IP address of the radio on port 4994/TCP

      In the SmartLink network configuration, you would map 4993 UDP to 4993 and map 4994 TCP to 4994 on the radio.

    If the radio is using a private IP address, then SmartLink is expecting the border router to perform a NAT on it and port forward the defined external UDP and TCP ports to the radio on ports 4993/UDP and 4994/TCP, respectively.

      It would help to see the SmartLink network setup screen.

      And there have to be specific pass or manual port forwarding rules specific to the port defined in the SmartLink setup from the outside to the inside, one for TCP and one for UPD.

    Tim Ellison, W4TME

    Customer Experience Manager

    FlexRadio Systems

  • Thomas NE7X
    Thomas NE7X Member ✭✭

    Issue Resolved, Thanks Tim...

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