I have just received a new modem to replace my old broken one, and all is working well, except I seem to no longer be able to connect to my internal home control app (Homeassitant) via the web address. I believe the modem is missing a NAT Loopback option (aka hairpin).
Is there a way to enable it? Or is there a workaround?
Solved! Solved: Go to Solution.
A manual entry in the hosts file should fix the problem. The 3864 performed Hairpin by default but not only is it not there by default for the 5366 the settings can only be viewed and not added or edited. The hosts file solution will only work on those wired or wireless machine with connection only to the Sagemcom. Regrettably most phones have host files that can't be accessed. Such is life.
Glad to hear that @Rixx7. We appreciate the positive feedback 🙂
To put my above comments into context, this was the situation.
Web sites and Virtual Machines which live within my local network and have an external dns addresses (for external users)
cannot be accessed from within my local network using the external address.
Some can, via local IP address, however I have 3 different subnets which I work between, so this was not a solution.
The Web sites and Virtual Machines could be accessed externally from outside my LAN on any other network connection or mobile.
This indicated that my port forwarding is working correctly for inbound traffic but outbound is either being blocked by the
DNS Servers, WAN firewall or other NBN higher powers!
This all pointed to a hairpinning (or NAT loopback) restriction using the Sagemcom FAST5366LTE-A.
This is not a local firewall issue as all sites worked perfectly with the previous Optus Sagemcom f@st3864 Modem Router and
then did NOT work using Sagemcom FAST5366LTE-A Modem Router withing the local network.
As mentioned, from the 15/04/2021, this has now started working! Access to all external VMs and sites on my local network can be accessed via their external addresses internally.
clearly an Optus update has been applied to the router or the pipe.
This has made my administration of these sites so much easier.