TP Link AC2100 on FTTP (BT Openreach) but sky fibre as provider

[Signum-GB]

As the title says, I have fibre direct to the home (FTTP) which was originally installed by BT Openreach and BT Infinity as the internet provider. I have changed internet provider to Sky (Sky fibre) and the Sky Q hub (which replaced the BT homehub) connected into the BT Openreach fibre modem (ONT) via WAN ethernet cable. No issues with connecting to the internet. Now the Sky Q hub isnt great for a number of reasons, so I upgraded to a TP-Link AC2100 with the view of connecting into the BT Openreach modem via WAN (same as previous Sky Q hub). Essentially the TP-Link replaces the Sky Q Hub as the wireless and hardwired router. The existing BT Openreach Fibre modem is already connected into the phone line, so for set up I wont be requiring it to operate in DSL mode (I don't think anyway). I presume I will need sky login details if setting up in WAN mode in order to log into Sky's internet service?  The photo below is an example of the BT Fibre modem which the TP-Link would be connecting into but how to get it to connect to the internet is another thing. 

Any pointers to send me in the right direction would be a great help. Most things I have found online and in Sky communbity assume there is no intermediate BT Fibre modem and plug straight into the phone line, using default parameters for Sky(MER)_VDSL set up (Sky Fibre). To be fair, I did try plugging this router/modem direct into the phoneline to see if I would get a DSL light but nothing. 

Hope some can help as I have trawled forum after forum today, but to no avail. 

Thanks

[TimmyBGood]

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@Signum-GB wrote:

 Most things I have found online and in Sky communbity assume there is no intermediate BT Fibre modem and plug straight into the phone line, using default parameters for Sky(MER)_VDSL set up (Sky Fibre). 

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Sky FTTP hasn't been around long enough for much experimentation: the setup you describe above would be correct for Sky FTTC.

The wiring for FTTP would be router WAN port (LAN4 on that model, I believe) to ONT Ethernet port but I can't say what the appropriate ISP settings are.

[Signum-GB]

Thanks for the response. 

Yes I am looking to use the TP-Link in wireless router mode as it will connect to the openreach fibre modem via LAN connection. 

ISP options, it is only 'other', then it asks for ISP credentials, but only offers PPPoE, Dynamic and static IP options. 

I have looked through the menus if setting up as a modem/router  then it does offer SKY MER selection with the option to add in the generic details that everyone else seems to use. If I can bypass the BT Openreach fibre modem then great, but even connecting direct to the phone line, the DSL light does not illuminate. Nothing happens, hence why I think my best option is somehow to get the connection to work over WLAN to the openreach FTTP modem. 

Cheers

[TimmyBGood]

@Signum-GB 

Well, bypassing the ONT is a nonstarter unless you can figure out another way of turning light into electrical signal ; )

There's very little point plugging things into the data port on a phone socket once you're provisioned on FTTP as the copper is no longer carrying a data signal (and quite possibly no phone signal either).

[Signum-GB]

Yeah understand that. Wasn't sure if the TP-Link unit I got had that inbuilt function of processing light signals on the fibre network. 

FTTP there must be a way to get this thing to connect via the WAN cable to the openreach box. I gather on other threads Sky don't use PPPoE, but the MER instead for authentication, but if setting up on the latter the TP-Link needs set up in DSL modem/router mode. 😞 

[TimmyBGood]

@Signum-GB 

I'm not aware of any  domestic router with optical / GBIC modules on either WAN or LAN sides.  

There have been some very useful posts by a Sky staff member on the subject of authentication (just don't mention MER ; )

Hello @-rpnz-  

[Signum-GB]

Thanks @TimmyBGood I will keep an eye out for further replies. 

With the Sky Hub I understand that does the authentication part for internet connection and it's ultimately getting the TP-Link to do the same thing. 

Cheers 

Ps happy new year when it comes. 

[Signum-GB]

@TimmyBGood Wasn't getting anywhere with this today, so resorted to piggy backing off my Sky hub via WAN dynamic IP configuration. I believe with BT Broadband FTTP I can use PPPoE and generic BT Broadband credentials with a WAN connection into the Openreach ONT. May just be a case of letting my Sky fibre contract lapse then sign up to BT again when that time comes unless a solution is found to this. Still.... got a much stronger WIFI signal throughout the house with the new TP-Link. 😄

[-rpnz-]

Hi,

Sky's FTTx products, both FTTC and FTTP, simply use DHCP over Ethernet, also known as "IPoE", to distinguish it from PPPoE.

For FTTC (VDSL2) services, including G.Fast, Openreach stipulate the use of 802.1q VLAN tag ID 101, but for FTTP (GPON), it's untagged.

There's no need for usernames or passwords, we use "port-based authentication" and is done based on information Openreach insert in to the DHCPv4/6 messages as the packets are forwarded through the Access Nodes (DSLAM or OLT).

For the majority of customers, approx. 80% of Openreach's footprint, we can authenticate DHCPv6 Prefix Delegation (PD) clients natively without any customisation required on the client.  Your DHCPv4 client can then piggy back off this authentication, also without any customisation.

For the remaining 20% of customers where Openreach do not add the required values in to DHCPv6, we need provide the DHCPv4 client in your router with an Option 61 or "Client-ID" value.  This option can contain any value, but best to follow the standard format we use, which is "<MAC>@sky|". (For legacy reasons which aren't really important, but there's still some regex that will delimit on that pipe character).

In saying all this, I believe all of Openreach's FTTP products fall within that 80%, so as long as you enable the DHCPv6 PD Client, you shouldn't need to worry about providing the DHCPv4 client with an Option 61 value.

Hope this helps, good luck with your 3rd party router.

[Eyewash01]

Thanks for the advice @-rpnz-. I did manage to get FTTP working to an extent with a TP-Link Archer C6 AC1200 by enabling ipv6, however it would always disconnect after a few hours (different intervals each time), and then I would have to fiddle around with it to get it to connect again (e.g. toggle the ipv6 setting / reboot the router etc) - would you have any idea why this might be?  I thought it might be some kind of authentication polling mechanism which is built into the Sky Hub but the 3rd party router wasn't able to do?

[-rpnz-]

By disconnect do you mean both DHCPv4 and DHCPv6 fail to renew the leases?  Or just DHCPv6 fails to renew the lease?

After a few hours is quite odd.  The lease time is 1 hour, so if the renews were failing, I'd expect it to be exactly every hour.

Other possibility is we send ARP, and ICMPv6 Neighor Solicits, to check that your CPE router is still there.  If you accidentally firewall off ICMPv6 NS for example, the IPv6 session will time out .  However that's in the region of 3 mins rather than hours.

Probably would need to see detailed logs of your router to see if there are any hints as to what's happening.

[Eyewash01]

Thanks for the reply @-rpnz- 

Unfortunately my router log only lasts about 30 minutes, and since your post, I happened to try again with a factory reset, and it's actually stayed connected since then which is great.

Still something weird going on though - these 4 rows get repeated in the logs every second:

And here's the IP status:

So I have all the ipv6 settings set correctly (otherwise it just won't connect) and it seems like it then manages to connect via ipv4 but not ipv6 - any idea?!  However like I say it has now been working for about a week.

[TimmyBGood]

@Eyewash01 

I believe Sky have not fully implemented IPv6 yet: @-rpnz- mentioned it somewhere else.

[-rpnz-]

Hi @Eyewash01 

I think your screenshots are just showing the WAN interface.  Unlike with IPv4, we do not assign an IPv6 address for use on the WAN interface, instead it's just Link-Local between your CPE router and our BNG.

You can see the Link-Local IPv6 address of our BNG listed in the "Default Gateway" field. This is good.

Currently our recursive DNS servers are only IPv4-capable, so it's perfectly normal to see those DNS fields empty as well.   You can resolve DNS queries(AAAA records) for IPv6-capable websites, over IPv4 transport.

The only thing I can say is that if you're seeing those log entries show up every second, It's probably your TP-Link hammering our DHCPv6 server trying to get a WAN address (IA_NA), which we don't support.  If you can find the option to disable IA_NA in the DHCPv6 Client, that'd should stop it. (IA_PD or "Prefix Delegation" is the important one you need to get a prefix for use on your LAN)

[-rpnz-]

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@TimmyBGood wrote:

I believe Sky have not fully implemented IPv6 yet: @-rpnz- mentioned it somewhere else.

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Hrm, not sure specifically what this may be referring to.  Our IPv6 deployment for broadband subscribers is fully implemented across the entire network and has been for years.

Maybe I was referring to our recursive DNS platform being IPv4 only currently?  

Or perhaps it was the ~80% of Openreach's network that doesn't support LDRA for DHCPv6 yet.  This is fine, we still support IPv6, it just means we cannot authenticate DHCPv6 natively, and we rely on DHCPv4 for authentication. (Which means having to include Option 61 Client-ID as well)