[Agrajag]

I switched to FiOS and ran into an issue where the R7000P (Nighthawk) isn't running at the speeds it should. The Verizon router ran at roughly 960 up and down whereas the Netgear is doing 400/700 at best with Shortcut Forwarding Engine enabled.

Several threads suggested that (with stock firmware) users were able to get full speeds once they enabled IPv6. On stock firmware that's as easy as checking an Automatic box and you're done. Not so simple with DD-WRT. Plus I have no idea what the right settings are.

Can anyone confirm that IPv6 works in DD-WRT (some have said it doesn't) and what the right settings for FiOS would be?

[MDA400]

The reason why IPv6 is faster at processing packets than IPv4, is because of the absence of NAT (network address translation. every IPv6 address is public on the internet), which induces a lot of overhead to packet processing (and results in lower bandwidth throughput).

Not sure what/if Fios is setup for IPv6, as I use Comcast and they provide consumer and business IPv6 addressing.
Yes IPv6 works in DD-WRT, provided you have a build that is within the last 5 years or so.

If your internet provider is delegating IPv6 addresses already to your LAN, in DD-WRT you would go to Setup (tab) > IPv6 (tab) > Enable IPv6 and choose "Native IPv6 from ISP".

But like most other ISPs that provide IPv6 connectivity, you would usually choose "DHCPv6 with Prefix Delegation" if they were to provide you a pool/prefix of IPv6 addresses to delegate to your LAN clients. You will see an "IPV6 WAN" address in the top-right corner of the DD-WRT admin site if your internet provider is providing IPv6 connectivity after enabling it in DD-WRT.

Enabling Radvd would then allow you to distribute those IPv6 addresses to your clients using "Stateless address auto-configuration" (SLAAC), which is supported by most major OSes like Windows, Android\Linux, and iOS\MacOS

DHCPv6 is a state-ful addressing server (you can control which addresses go where on your network), but android does not support this.

Comparison of IPv6 support in operating systems