changing native ipv6 Prefix Length

[hufflepuff]

first ever posting, so be gentle.
i have the following issue and i can't seem to solve it.

first basic info: my isp dishes out fixed ipv4 and ipv6 and has native ipv6 support. i am using a AC66U if that matters.

now the issue is that my isp give out /48 adresses but for some (stupid) reason the (latest) merlin firmware only allows /64.
i have tried running the following commands:

nvram set ipv6_6rd_prefix_length="48"
nvram commit

that does seem to change it, but a following reboot instantly returns it to 64, so does just pulling the wan cable (no reboot).

is there a way to release the diabolical seals of the devil and allow me to change the prefix myself? without this i cannot get ipv6 to work properly wich sucks really bad as the isp router has the processing power of a bucket of sand.

 

[defaultroute]

Bump. I'd also like to know this. Supposedly TWC will give you a /56 if you ask for it.

 

[easyriider]

The delegating router, mostly the modem connected to the provider, defines the prefix length it gives to the requesting router. You cannot override that with a nvram setting. Normally the delegating router will not give a requesting router it's whole prefix length. So it's possible that it gives away /64 prefixes if it gets a /56 from the provider.

 

[lilCodie]

TWC will infact do this easyriider - heres the info on it https://major.io/2014/09/11/howto-time-warner-cable-ipv6/ - also interested - even if it means having to set it in the nvram on boot or somehow else (manual config override with a .conf file on asuswrt-merlin)