Third party router with FTTP

[Pete-da-Meat]

After a lot of packet sniffing and tinkering, I've managed to get my home landline phone to work whilst using a third-party router, and it's been stable for over a week.

Disclaimer: I am a network engineer with a home lab, access to a virtualisation environment and enterprise-grade network kit. I do not work for Sky. I started this mini-project to scratch an itch (i.e. it was annoying me that it didn't work). As described, it is highly unlikely that this solution is appropriate for anybody. 🙂

[Sky FTTP] -> [3rd Party Router] -> [Sky Router] -> [Phone]

The 10,000 foot view of my solution is:

• Get your 3rd party router working for IPv4 & IPv6 (including DHCPv4 option 61 and DHCPv6-PD configuration).
• Host a DHCPv6-PD server on a router/server, advertising a subset of your PD allocation (e.g. I used the trailing /60). I used an HPE MSR router for this (lol), but you could easily use another product such as ISC Kea or maybe pfsense.
• Connect your 3rd Party router to yourSky router to your
• Sky router gets an RFC1918 IPv4 address via DHCPv4 (I had to play with option 43 to get this working).
• Sky router gets an IPv6 address via SLAAC (I think).
• Point a static IPv6 route from your 3rd party router to the Sky router for the /60.
• Sky router gets an IPv6 PD prefix from the DHCPv6-PD server.
• Write some ACLs on your 3rd part router to allow incoming IPv6 to the Sky router for the /60 range.

I will admit, my solution is "rather convoluted", and currently requires manual reconfiguration if my IPv6 PD allocation changes (which so far has only only happened when I've been messing around with things). Looking to do some tests with ULA and NAT-PT to get around this.

If there is enough interest, then I will try to iron out the wrinkles and write a detailed post in a couple of weeks.

PTM

[SnowWolf20]

Where did you find this information?

123456789ab@skydsl|abc

[Pete-da-Meat]

Mostly by analysing pcap files in Wireshark and debug/diagnostic output on my router.

[pearsori]

Can anyone help me please

connected my Drektek 130 modem directly to my computer changed it to bridge mode, then reconnected to network, unplugged sky router and plugged drektek into wan port of new Synology router.

my backup won't find the default 192.68.1.1 and self assigns an ip instead, I have rebooted all my switches abs renewed dhcp leases but network won't find anything. 

 Am I doing something wrong? Do I need to plug back in sky router and add Synology router to the network or connect Synology router to my machine directly?? 

[Metalwolfy]

I'm trying to get FTTP working on my Mikrotik router and its got me scratching my head.  I've set option 61 on ipv4 and ipv6 and enabled ipv6 prefix but I never get addresses.  Has anyone managed to get sky FTTP working on routeros and can give me some pointers?  Much appreciated.

Well done on getting the phone to pass through.

[cookiemonsteruk]

@Metalwolfy 

Could you screen grab and post the settings screen that has dhcp option 61 settings to get you up and running

[Metalwolfy]

I didn't expect someone to reply so quickly!  I have attached screen shots of the dhcp client settings where you set this.  the 0x is hex for a username and password I found on the mikrotik forums.  I've checked and it appears to be the correct format.   I've shown both the IPv6 and IPv4 configuration:

 

Your help is very much appreciated.

[Metalwolfy]

12c1ab12aa12@skydsl|123a1a12 is what the 0x31326331616231326161313240736b7964736c7c3132336131613132 converts to which seems to be in the same format as previously mentioned in the post.

[cookiemonsteruk]

@Metalwolfy 

The format for dhcp option 61 client id is 

anything@skydsl|anything

Some 3rd party router manufacturers do specify hexadecimal

In that case just use the routers mac address ie

Mac_address@skydsl|last_6_characters_of_MAC

Yours seems to be duid which won't work with sky

[cookiemonsteruk]

@Metalwolfy 

Use the actual client id in your post above. Do not convert to hex. The @skydsl| must appear the way it is typed

[Metalwolfy]

Unfortunately with mikrotik it requires it be stored in hex, as soon as I try to put it in as my macaddr@skydsl|maclast6 it complains its an invalid format.  

I have converted that to hex and I'll see if it likes that (once I can get everyone off the broadband).

With regards the client_duid thats a default thats set on mikrotik and as best I can tell I'm not passing that to sky (upper right picture) and only sending the clientid.  What I'm unsure is whether its converting back from hex.

I did find on the mikrotik forum people getting it to work with the hex but that was not FTTC or FTTP.

[cookiemonsteruk]

@Metalwolfy 

We may have to look in more detail at dhcpv6 prefix delegation

In a nutshell that involves

Selecting ipv4/ipv6 (dual stack) on the wan

Enabling dhcpv6 (dynamic) on the wan

Enabling pd/prefix delegation on the wan

For address creation on the lan select stateless/slaac

[Metalwolfy]

Ok that is definitely something I haved missed.  It looks like slaac is referred to as neighbor discovery and I can see information on setting that up on ipv6.  I will give that a go after work.  Fingers crossed.

[greendragons]

@Pete-da-Meat that's awesome!

I've been wondering if this was possible for a good while, but lack the network engineering background (and high-end kit!). I'd be really interested in your write-up, if you have a chance to iron out the wrinkles.

Based on your instructions, I'm going to experiment more with the kit I have available here.

Thanks for your perseverance, and for posting your findings.

[CaveMaster]

Hint..

Mikrotik accepts the single quote before a text string

'macaddr@skydsl:aaaaaa'