IPv6 PD Sky Broadband (UK)

armitasp

After a bit of trial and error, I managed to get IPv6 working with Sky Broadband. For anyone else looking with Sky Broadband here is what worked for me:

(Interfaces > WAN)

In the WAN Interface config select DHCP6 as the IPv6 Configuration type:

Screenshot 2023-10-07 at 14.09.12.png

In the DHCP6 Client Configuration for the WAN interface tick the following options

Use IPv4 connectivity as parent interface
Send IPv6 prefix hint
Do not wait for a RA

DHCPv6 Prefix Delegation size is a /56

Screenshot 2023-10-07 at 14.11.09.png

(Services > DHCPv6 Server & RA)

In LAN > DHCPv6 Server > DHCPv6 Options:

tick enable DHCPv6 Server
set Prefix Delegation Size to /64

Note: The delegated prefix in subnet should be a /64

Screenshot 2023-10-07 at 14.18.04.png

In LAN > Router Advertisements:

Router Mode is Assisted

Screenshot 2023-10-07 at 14.22.17.png

PlyrStar93

"DHCPv6 Prefix Delegation size is a /56" - it should probably be a /64 as seen on the delegated prefix on your LAN interface (2a02:c7c:xxxx:xxxx::/64). The ISP's device likely ignored your /56 PD request and gave you a /64.

"Note: The delegated prefix in subnet should be a /64" - it shouldn't matter if you do not delegate prefix into subrouters (i.e. router connected to your LAN network). In this case you left LAN DHCPv6 server's prefix delegation range empty, and the PD size there doesn't do anything. Either way, if your ISP only gave you a single /64 you won't be able to further delegate it into routers behind your LAN (or you may but it will very likely break, and SLAAC won't work on prefix size smaller than /64).

I think the only critical options are among the following:

Interfaces > WAN > IPv6 Configuration Type > DHCP6
Use IPv4 connectivity as parent interface
Send IPv6 prefix hint (can't even be sure of this, there might not be need to enable this)
Do not wait for a RA
LAN > IPv6 Configuration Type > Track Interface (you probably missed/skipped this)
LAN > Track IPv6 Interface choose WAN
DHCPv6 Server >LAN > enable DHCPv6 Server
Enable router advertisement on LAN

armitasp

@PlyrStar93 said in IPv6 PD Sky Broadband (UK):

"DHCPv6 Prefix Delegation size is a /56" - it should probably be a /64 as seen on the delegated prefix on your LAN interface (2a02:c7c:xxxx:xxxx::/64). The ISP's device likely ignored your /56 PD request and gave you a /64.

"Note: The delegated prefix in subnet should be a /64" - it shouldn't matter if you do not delegate prefix into subrouters (i.e. router connected to your LAN network). In this case you left LAN DHCPv6 server's prefix delegation range empty, and the PD size there doesn't do anything. Either way, if your ISP only gave you a single /64 you won't be able to further delegate it into routers behind your LAN (or you may but it will very likely break, and SLAAC won't work on prefix size smaller than /64).

Sky hand out /56 prefixes, and as far as I am aware, and from the logs that is what it appears to assign to my router. (I have XXX out part of the subnet)

Oct  8 11:45:33 pfSense dhcp6c[13437]: send solicit to ff02::1:2%vtnet0
Oct  8 11:45:33 pfSense dhcp6c[13437]: reset a timer on vtnet0, state=SOLICIT, timeo=1, retrans=2083
Oct  8 11:45:33 pfSense dhcp6c[13437]: receive advertise from fe80::22%vtnet0 on vtnet0
Oct  8 11:45:33 pfSense dhcp6c[13437]: get DHCP option server ID, len 10
Oct  8 11:45:33 pfSense dhcp6c[13437]:   DUID: <removed>
Oct  8 11:45:33 pfSense dhcp6c[13437]: get DHCP option client ID, len 14
Oct  8 11:45:33 pfSense dhcp6c[13437]:   DUID: <removed>
Oct  8 11:45:33 pfSense dhcp6c[13437]: get DHCP option identity association, len 49
Oct  8 11:45:33 pfSense dhcp6c[13437]:   IA_NA: ID=0, T1=0, T2=0
Oct  8 11:45:33 pfSense dhcp6c[13437]: get DHCP option status code, len 33
Oct  8 11:45:33 pfSense dhcp6c[13437]:   status code: no addresses
Oct  8 11:45:33 pfSense dhcp6c[13437]: get DHCP option IA_PD, len 41
Oct  8 11:45:33 pfSense dhcp6c[13437]:   IA_PD: ID=0, T1=1800, T2=2880
Oct  8 11:45:33 pfSense dhcp6c[13437]: get DHCP option IA_PD prefix, len 25
Oct  8 11:45:33 pfSense dhcp6c[13437]:   IA_PD prefix: 2a02:c7c:8XXX:6600::/56 pltime=3600 vltime=3473388667010027024
Oct  8 11:45:33 pfSense dhcp6c[13437]: server ID: <removed>, pref=-1
Oct  8 11:45:33 pfSense dhcp6c[13437]: reset timer for vtnet0 to 0.994070
Oct  8 11:45:34 pfSense dhcp6c[13437]: picked a server (ID: <removed>)
Oct  8 11:45:34 pfSense dhcp6c[13437]: Sending Request
Oct  8 11:45:34 pfSense dhcp6c[13437]: a new XID (dcd8c5) is generated
Oct  8 11:45:34 pfSense dhcp6c[13437]: set client ID (len 14)
Oct  8 11:45:34 pfSense dhcp6c[13437]: set server ID (len 10)
Oct  8 11:45:34 pfSense dhcp6c[13437]: set status code
Oct  8 11:45:34 pfSense dhcp6c[13437]: set identity association
Oct  8 11:45:34 pfSense dhcp6c[13437]: set elapsed time (len 2)
Oct  8 11:45:34 pfSense dhcp6c[13437]: set option request (len 4)
Oct  8 11:45:34 pfSense dhcp6c[13437]: set IA_PD prefix
Oct  8 11:45:34 pfSense dhcp6c[13437]: set IA_PD

Whilst I only care about IPv6 on the main client VLANs I thought I'd test it has received a /56 and turn on IPv6 on my management network. using PD 1 (PD 0 being the LAN interface).

This did assign the next /64 from the /56 to the management network

vtnet1: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
	description: LAN
	options=800b8<VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,LINKSTATE>
	ether 7e:eb:be:b4:7a:e5
	inet6 fe80::7ceb:beff:feb4:7ae5%vtnet1 prefixlen 64 scopeid 0x2
	inet6 fe80::1:1%vtnet1 prefixlen 64 scopeid 0x2
	inet6 2a02:c7c:8XXX:6601:7ceb:beff:feb4:7ae5 prefixlen 64
	inet 10.1.0.1 netmask 0xffffff00 broadcast 10.1.0.255
	media: Ethernet autoselect (10Gbase-T <full-duplex>)
	status: active
	nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
vtnet2: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
	description: MGMT
	options=800b8<VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,LINKSTATE>
	ether 66:e5:98:90:8d:cc
	inet6 fe80::64e5:98ff:fe90:8dcc%vtnet2 prefixlen 64 scopeid 0x3
	inet6 fe80::1:1%vtnet2 prefixlen 64 scopeid 0x3
	inet6 2a02:c7c:8XXX:6602:64e5:98ff:fe90:8dcc prefixlen 64
	inet 192.168.0.1 netmask 0xffffff00 broadcast 192.168.0.255
	media: Ethernet autoselect (10Gbase-T <full-duplex>)
	status: active
	nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>

I think the only critical options are among the following:

Interfaces > WAN > IPv6 Configuration Type > DHCP6

Use IPv4 connectivity as parent interface

Send IPv6 prefix hint (can't even be sure of this, there might not be need to enable this)

probably doesn't need to be set but why not hint what you want. Sky will probably ignore anything larger than a /56 but may give you what you want if you ask for smaller

Do not wait for a RA

LAN > IPv6 Configuration Type > Track Interface (you probably missed/skipped this)

Yep, that's missing

LAN > Track IPv6 Interface choose WAN

DHCPv6 Server >LAN > enable DHCPv6 Server

Enable router advertisement on LAN

JKnott

@PlyrStar93 said in IPv6 PD Sky Broadband (UK):

about 11 hours ago

"DHCPv6 Prefix Delegation size is a /56" - it should probably be a /64 as seen on the delegated prefix on your LAN interface (2a02:c7c:xxxx:xxxx::/64). The ISP's device likely ignored your /56 PD request and gave you a /64.

No, it should be 56, assuming that's what the ISP provides. That's the size you're requesting, which has nothing to do with your LAN, which is normally /64.

mikey_s

I've just put pfsense 2.7 in for my parents Toob connection, it's a IPV4 CGNAT / IPV6 service and I think they allocate /56. Not needed to carve up VLANs etc. it's a flat network. I must check the log file myself to confirm what they had out.