Yet Another Port Forwarding Malfunction (The MAP-T chronicles)

[Endgame901]

Hello everyone. Here's the skinny.

I'm trying to run a game server in a Linux VM on a Windows host machine. I'll add the VM connection details below if anyone thinks they're relevant, but the host machine is connected to a standard 5-port dumb switch via ethernet cable, which is connected to my Sky Max Hub via ethernet. So far, so good.

I set up port forwarding on my Sky Max Hub for the VM via the My Sky app. The ports, in particular, are 2456-2458 for TCP/UDP. 

My Sky connection details on my router show MAP-T as enabled with a ratio of 1:1. From everything I've read, it's supposed to work. It does not. 

I've used several different port checking sites, and there appears to be no open ports at all to my WAN IP, let alone the ports I specifically set as forwarded. It's almost like it's still shared, even though it's 1:1. Weird right?

So I contacted Sky at 11 this morning, asking for MAP-T to be disabled entirely. They said it'd be a couple hours... well that was a lie! So I'm here to see if anyone in the community might have any other ideas. I don't see why it should matter, but I can bypass the 5-port switch and use wi-fi instead, just in case anyone thinks the switch is interfering!

Thanks for any help provided!

Regarding the VM connection details: the ethernet adapter is set to Bridged. Meaning, my host PC and my VM both appear on My Sky as separate connected devices. I attempted to set up port forwarding for the host machine instead just in case. No dice!

[JimM1]

@Endgame901 Sky Max hub and Map-T are hand and glove!

[Endgame901]

I'm...not sure what you mean by this? Can you elaborate?

[JimM1]

@Endgame901 You have a sky Max hub, then you are using the MAP-T network protocol wether it be a 1:1 or a 1:8. Would double check your IP to the server and make it a fixed IP for ever!

[Endgame901]

Yes I'm aware I'm using the MAP-T protocol. That appears to be the problem. I've already asked Sky to disable it on my router but they're taking their time. So I'm throwing a hail mary here to see if anybody can think of something I haven't tried.

I've checked and rechecked the IP dozens of times. Just to be really clear, this is not a remote virual machine. The virtual machine is running on my own computer. So it's public IP is the same as my computer's public IP, which is the same public IP every other device in my home will have because it's the WAN IP of the router.

The port forwarding rules on the router are set to forward the requisite communications to the virtual machine, and they are not working. This is why I've asked Sky to turn off MAP-T on my router; every other post I've seen here detailing this problem says "If it's not working as designed, Sky needs to turn off MAP-T for you".

I'm just re-iterating everything again because I'm not quite what it is you're suggesting.

[Chrisee]

@Endgame901 not exactly sure what your issue is but the port forwarding on the Sky Max and the use of MAP-T are probably two separate issues. The sharing of external IP addresses that MAP-T allows does upset some VPNs and external access for some applications but has nothing to do with the firewall rules on the hub.

Port forwarding is a means of allowing external devices from  accessing an application runjing on a specific internal device behind the hub's firewall. It is a comparatively rare thing these days as systems like uPnP etc has taken over. The port firesrding on the SR213 hub is known to be flaky and while it can be made to work for some gaming applications I would not recommend it for any serious usage. However you can test if it is the issue by temporarily placing the machine running the virtual machine in the Sky Hub's DMZ it isnt something you should do permanently as you have effectively bypassed the firewall. If the issue continues then it is an issue with the address sharing however Sky tell us thst setting up a port forwarding, using the DMZ or enabling uPNP automatically switches off address sharing. 

Honestly while the Sky hub is suitable for most domestic networks it is so locked down it is not a good choice for experienced users. Use of a third party router is far better with only one drawback which is loss of the digital voice line which requires a Sky hub. Asus routers work well on most Sky connections as they support the older DHCPv4 Optiin 61 Sky use as a fallback on lines that dont support DHCPv6 PD.