Sky Fibre & Unifi Dream Machine

[Chrisee]

@KGx to explain my post which is a guess as your connection worked then stopped which implies a config change some where broke it. We know Sky are switching customers to this method to make IP4 addresses stretch further @cookiemonsteruk and myself attended a presentation a few weeks back when Sky told us that third party routers would be switched at some point. The older black Sky hubs dont support the system so the servers ignore them but it applies to the newer white SR213 hubs.

i am not very knowlegable about your UDM but this support thread https://community.ui.com/questions/Feature-RequestMAP-T-MAP-E-carrier-grade-NAT/4003b1d9-6bd4-4ef7-9... implies it still doesnt support MAP-T 8 years after the intial request. 

[KGx]

Unfortunatly it doesn't let me do that

[KGx]

@Chrisee - Thanks for the information on this, so from a customer stand point,  do you know what the next steps are on this?

Obviously it's not ideal for customers to be experiencing it, nor having to daisy chain through a hub to get the network back working is a terrible thing to have to do.

[Chrisee]

@KGx I repeat my post is a guess. However as Superusers we have access to Sky staff - hence the briefing I mentioned - I will check if such a switch was made this morning and if the technical contact think this is possible theory.

Sky's official position is they don't support third party routers however they know a small minority of customers choose to do so and the SU group are encouraged to offer support. However if a particular model router works or not is not something officially they care about. Ubquiti kit is complex and not widely used in my experience.

[KGx]

@Chrisee - Thank you for that info, totally get the 'lack of care' that Sky have for us users at the moment, after spending 2 hours on the phones this afternoon with the technical team & them just dismissing every smidge of an issue & stating that "sky router is better than anything else ever".

It's not a great time at all, I appreaicate you being willing to reach out to your contacts & i'll await further commucation from you on this.

Long shot but if that's something that has been switched on, surely it could be switched off for certain users?

[Chrisee]

@KGx I have asked the question and if Inget an answer I will update the thread.

Sky's response you got is 100% expected you are likely to  get the same from any large mass market ISP they each have millions of customers and simply do not support third party kit. Smaller isps like Zen are better placed to provide the support you need.

[jpdguk]

I have the same setup UDMP -> ONT, which has been working amazing for many months. Then suddenly yesterday morning at about 2am and again at 9am this morning, the internet just dropped. I've had fibre to the house for over a year and this is the first time its dropped.

My UDMP just stopped conecting to the internet. I eventually plugged my Sky Router back in and after a long time (and many resets) the internet came back (with a new WAN IP). I plugged my UDMP back in (with no config changes) and the internet started working again!

Then this morning and 9am, it just dropped again! Went through the same process, put the Sky router back and then it would not get a new WAN IP. It sat there for ages with 0.0.0.0 as its WAN IP (all the time the Internet light on the router was green!). Then finally it got a new WAN IP and it was working. After a few hours of running from the Sky router, I've switched back to the UDMP. So far so good...

Through reading I've come accross posts about the UDMP not supporting  the correct protocols to survive a WAN IP reset, so I'm concerned that if Sky decided to reset my WAN IP my connection will drop again.

In a recent Unifi update they introduced a new option for "DHCP CoS" and I'm wondering if that would help at all?

 My current (working config) looks like this (although I only get an IPv4 WAN address and no IPv6)

[KGx]

@jpdguk - Well i'm glad i'm not the only one, that's a releif.

I'll try some of your steps this morning & see if I can get any joy.

When you say many resets, we're you resetting the UDMP or the sky router, also for the life of me I can't seem to find the WAN IP, do you mind directing me to this?

[KGx]

@jpdguk - just an update to this, tried what you suggested all morning to no avail.

But thankfully had someone from the Unifi forum (linked here) state that if you disable IPv6 it will work wihtout having to go through the Sky Hub to UDMP, I disabled IPv6 & BAM worked flawlessly, not loosing any speed, will continue to test to see how it goes throughout the day.

With that though it seems theres a few different linked articles about the whole MAP-T and IPv4 sharing etc.

It looks like there is an opt out feature that @Chrisee you seem to be part of a thread on, do you know how as customers we opt out of this IPv4-Sharing? (top of this tread)

[-rpnz- · Accepted solution]

Hi @KGx 

Glad you managed to find the solution yourself, but yes just to confirm the issue is due Ubiquiti Unifi routers asking for MAP-T (by including DHCPv6 Option 95), but then not actually supporting MAP-T.

The ideal solution would be for Ubiquiti to develop support for MAP-T, the next-best solution would be for them to stop asking for MAP-T until they do support it.  The next best solution is as you've found, sadly disabling DHCPv6 on the WAN (not something I would usually recommend!). 
Finally, we do have the ability to forcibly disable MAP-T per service if we have to, if anyone is reading this and is having this exact issue but also really wants to keep IPv6, feel free to DM me and I'll see what I can do.

[Chrisee]

@KGx you have your answer in the post by @-rpnz- 

Switching off IP6 is a poor cludge but unfortunately the issue is caused by Ubiquiti's firmware advertising a feature to servers it cannot in fact support. Sky have been using MAP-T in Italy for years but this was raised in the Ubiquiti forum message I linked 8 years ago and still they haven't added the support. Other ISPs will be using the same or similar systems as the price of IP4 address blocks rise. . 

Understandbly Sky want to limit the number of people requiring an IP4 address of their own rather than sharing so this will I suspect remain a manual process which the normal customer support channels wont handle. The forum Superusers and the forum managers will pick up posts as they appear and will link people to the appropriate solution as we do where company VPNs object. 

[PeterMaguire]

I'm having the same issue but disabling ipv6 hasn't helped. I am getting a CGNAT IPv4 address assigned just fine but requests are timing out. Does the IPv4 configuration need changing for this? I'm using DHCP with option 61+60 which was working fine before.

[Chrisee]

@PeterMaguire i will escalate your post to the Sky team who support the forum who should be in touch soon to offer you a private chat session to get this sorted. Keep an eye on the forum as if you miss the message just click the chat icon which will be added to the forum pages for you to use.saving a long phone call.

[-rpnz-]

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@PeterMaguire wrote:

I'm having the same issue but disabling ipv6 hasn't helped. I am getting a CGNAT IPv4 address assigned just fine but requests are timing out. Does the IPv4 configuration need changing for this? I'm using DHCP with option 61+60 which was working fine before.

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The old session must still be active for you to obtain an RFC6598 IPv4 address  (100.64.0.0/10).

If you can tell your device to "disconnect" and force it to send a DHCPv4 Release, that should clear it out, and force a re-authentication that (without DHCPv6 enabled), should fall back to native IPv4.  Keep DHCPv4 Opt 61 as is.

If the device has no disconnect function, instead you can leave the device disconnected for 1hr so the old session definitely times out, before reconnecting it.

[PeterMaguire]

Thanks for the response, this worked. I got a new IP which is not a CGNAT IP this time and eveything seems to be working.