Hairpin NAT Loopback not working?

  • I am having issues with hosting a public facing (port forwarded) game server while also accessing the server from another machine on my subnet. The issue seems to be with NAT Loopback support.

    Linux Server hosting game: (ports forwarded)
    Desktop trying to connect:

    The server won't show up however when searching for it on a different network (let's say using cell phone service) it shows up.

    Does the Alien not support hairpinning? Or am I missing something?

  • Support replied:"Unfortunately, Alien router does not support Loopback aka hairpinning. I will surely forward it as a feature request to the development team."

    Disappointing a $400+ Wifi Router doesn't support a fairly simple feature.

  • I'm surprised by this too. It's not that uncommon to access your own NAS, or for applications like cURL that do loopback requests.

  • Surprised I can't do this on the HD.

  • I don't know if I have the same issue. I can not access my local NAS https://external adress:port via LAN from a PC or Mac connected directly to the Alien via cable (NAS is also direct connected to Alien). But if I remove the LAN cable over WIFI it is working. Anyone an Idea what can be the issue?

  • Nummerelf, I am experiencing the same issue. WiFi-LAN works, but LAN-LAN devices dont work.

    I swear this was working a few months ago though as I was succesfully using NAT Hairpinning a few months ago

  • @Robert-Pivac To my knowledge, this has never worked as it has never been a feature of the AmpliFi range. Would love to see it happen though. Nextcloud is currently saturating my WAN's upload with devices on the LAN uploading via the WAN to the server on the LAN because of the lack of hairpin NAT. Complete madness.

  • Not sure about the Amplifi HD's, but it seems to work on the Alien after some troubleshooting with nummerelf (and now that I know there is a known issue I also worked around it by connecting devices to different ports on the Alien.

    If you can access the beta group, all the details are here on page 3.

  • Hi @Robert-Pivac , do you have any new on this issue ?

    I'm planing to buy a Amplifi Alien but but it really blocks me from buying it.


  • @Jean-Squillari NAT Loopback AKA Hairpinning does work, but only if connected to different network ports on the Amplifi.

    For example:
    Amplifi LAN Port 1 running server. Amplifi LAN Port 2 running a client, both can connect using a Public IP address and NAT Hairpinning.

    However what does not work is multiple devices behind the same LAN Port.

    For Example: Amplifi LAN Port 1 connected to a Switch. Switch Port 1 running a Server. Switch Port 2 running a Client. NAT Hairpinning does not work as both Server/Client are using LAN Port 1.

    To work around this, I had to place my servers on LAN Port behind a Switch. And then my client devices such as PC's on LAN Port 2 behind another switch.

    In this setup, most things work fine.

  • @Robert-Pivac I tested this on my Alien, I don't think this solution solved my problem. I have my Nextcloud connected to a switch which goes to Port 4 on Alien, and I have a Rpi connected to Port 3. Can't access the public domain.

    Although even if this worked on my Alien, it will only work with wired devices, I suspect.

  • Anyway I got it working by using Pi-hole. I added the public domain in the DNS record (in Pi-hole). Now the loopback works.

  • This is absolutely still needed.

Log in to reply