Port forwarding not working on Sky Max Hub

[robbtong]

Hi

I have just signed up to Sky and have received the Max Hub. When I'm trying to configure port forwarding to my Home Assistant box, the port forward does not work.

Called Sky and spoke to someone who said change the Wifi to WPA2 as they had seen this issue with VPN setups and this had fixed it. On checking mine, it was already set to WPA2.

The Home Assistant box is connected directly to the Hub Max via an ethernet cable. To troubleshoot, I removed the Sky Hub Max and replaced it with my own router that runs OpenWRT which conencted directly to the Sky ONT with DHCP Option 61 configured to make it work. 

Set the port forward on that box and it goes straight into the Home Assistant dashboard externally. Switched back to Sky Hub and nothing.

The person on the phone said he had no idea if the WPA2 change didn't fix things, so hoping someone on the forums can help. What I found strange as well is that if you try and change the name of a device on the Sky App, it says that an error has occured no matter how many times I've tried. That strikes me as a communication issue to the hub in sending it's settings over.

Thanks in advance.

[JimM1]

@robbtong Link for changes on the sky Max.

Sky Max change settings link.
https://www.sky.com/help/articles/change-wifi-max-hub-settings-a

[robbtong]

Hi

I've applied the settings as per that page but the hub doesn't seem to be paying any attention. 

[robbtong]

Funny enough it seems to work if you set the DMZ IP to the box I want to forward to, but thats not ideal as it opens up every port to be forwarded.

[JimM1]

@robbtong You mat have to get sky to fix out the MAP-T for the sky max, see the pinned post at the top of the page!

[-rpnz-]

Hi @robbtong 

By default the Sky Max Hub shares an IPv4 address using MAP-T; normally this would prevent port forwarding as you don't have exclusive use of all ports, but the Sky Max Hub should detect whenever you add a port forward, and do what we call "opt-out" of IPv4 address sharing, giving you an entire IPv4 address to use yourself.   It's possible this automated process has not worked.

In the Sky Max Hub's web interface, on the left navigate to "Connection" and then "Sky Network" and then look for two fields:

• WAN IP Address (IPv4)
• MAP-T Sharing Ratio

If the WAN IPv4 Address field simply has an IPv4 address--nothing in parantheses--then you're on Dual-Stack and port forwarding should be working.

If the IPv4 address is followed by "(Shared with MAP-T)" then you're connected using MAP-T rather than native Dual-Stack.  That in itself is not a problem, the important thing to check out is the MAP-T Sharing Ratio down the bottom. 

If the sharing ratio set to "1:1" then you have been opted out correctly and port forwarding should be working correctly. 

If the sharing ratio is anything else (8:1 in the UK), even after enabling Port Forwarding/DMZ/etc. then the automated opt-out process may not have worked correctly.   In theory this should resolve itself after 12hrs, but if it doesn't, feel free to direct message me and I'll sort it out for you.

[crossmr]

Hi rpnz, 

According to my connection, it says MAP-T sharing ratio 1:1, my IPv4 address does have (shared using map-t) in it. 

I've got the program running on my machine, verified it's listening to the port with netstat, port is open on my firewall (has been for years), went into the app, chose my device (verified it's right), and then forwarded those ports. Port checking sites still report the port as completely closed. 

[-rpnz-]

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@crossmr wrote:

According to my connection, it says MAP-T sharing ratio 1:1, my IPv4 address does have (shared using map-t) in it. 

I've got the program running on my machine, verified it's listening to the port with netstat, port is open on my firewall (has been for years), went into the app, chose my device (verified it's right), and then forwarded those ports. Port checking sites still report the port as completely closed. 

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Hi @crossmr 

If the sharing ratio says it is 1:1, then it should be working.  Or rather, we know it's the IPv4 sharing that's causing an issue.

The issue we found that @robbtong was having, is that the port forwarding was to the wrong IP on the LAN.  This was because the server on the LAN had initially connected using DHCP, which the Sky Hub (and App) learns and maps this host to IP, but he had since set the host to have a different manually configured IP.    The Sky Hub & App then get confused and continue to use the old server IP, learnt from DHCP.

I've raised this is a bug/feature request with our Sky Hub team, but for the mean time, the best way to avoid this is to keep LAN hosts using DHCP, but set them a fixed IP via DHCP in the Sky Hub web interface (or also doable in the App, I think?)

When adding the Port Forward,  confirm the auto-populated IP address is the same one the server on your LAN has.

Hope that helps!

[robbtong]

Hi

The port forwarding suddenly stopped working this morning. Has been fine since we fixed it. 

The MAP-T bit looks ok as it says is sharing 1:1, but no matter how many reboots I try nothing fixes the port forwarding.

Has something changed sky side?

Thanks in advance

Robb

[-rpnz-]

Hi Robb,

No, no changes that should impact your port forwarding, sorry.

[antouonne]

I'm another for whom Port Forwarding is failing. I have followed this string and found that I am connected to MAP-T with a sharing ratio of 1:1 - are you able to help?

[-rpnz-]

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@antouonne wrote:

I'm another for whom Port Forwarding is failing. I have followed this string and found that I am connected to MAP-T with a sharing ratio of 1:1 - are you able to help?

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Hi @antouonne 

Thanks for checking that the IPv4 sharing ratio is 1:1, that confirms the network is working as expected, it has detected that you're using port forwarding and has updated accordingly;  whatever the problem may be, it's not an issue with MAP-T and IPv4 address sharing.

Make sure the host on the LAN is still using the same IP address as was used for the port forwarding rule.  Best method is to make sure it's using DHCP (not manually configured), and configure a fixed lease/static IP for that host in the Sky Hub or app.

[antouonne]

Thanks - I've tried all that including allocating static IP and rebooting the router without any change in the end result - just to let you know I had previously tried WPA2 also without success, so I went back to the original. The Hub appears to have the correct information but the port forwarding (Port 9742/UDP) is failing.

[-rpnz-]

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@antouonne wrote:

Thanks - I've tried all that including allocating static IP and rebooting the router without any change in the end result - just to let you know I had previously tried WPA2 also without success, so I went back to the original. The Hub appears to have the correct information but the port forwarding (Port 9742/UDP) is failing.

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Hi @antouonne , can you confirm how you're testing the port forwarding please?

Unlike TCP, port forwarding UDP won't show up on any external port checkers, as UDP is connectionless protocol.     The only definitive way to validate UDP ports is with the application that's listening/using the port.

Given all the other debugging you've already done and things you've ruled out, I'd be looking at the host on your LAN to make sure the application is running and listening on the correct port and there's no additional firewalling on the host itself.  Make sure it has a default route out to the Internet.

Ideally if you can check the application can connect to the host internally from another device on your home network?

[antouonne]

Yes, I have been checking through the application (PlanePlotter) - I'll have to try the suggestions you made a bit later as things are starting to get busier...