If you have firmware prior to IPv6 it'll work, as you can turn off IPv4 DHCP and job done, any upto date box will still assign an IPv6 address to devices and there ends up no data throughput, with around 25% of devices resolving an IPv4 address as expected (but it's total pot luck whether the IPv4 or v6 gets assigned first). If the IPv6 gets resolved, then IPv4 does not resolve to the main hub and you get 169 self assigned IPs.
If BT allowed you to turn off IPv6 it would solve all of this, alas, they don't offer that.
EDIT: Misread post as HH6, should be fine on HH4!
Edited by ukhardy07 (Thu 14-Dec-17 23:32:42)