[IPv6] Do not wait for RA option or automatically add default route

[fl4co]

My ISP assigns a IPv6 prefix via PPPoE. However, they do not send a Router Advertisement packet. I don't know if it's a technical limitation of IPv6 via PPPoE or choice by the ISP.

The result is that the Keenetic router gains the delegated prefix, but no IPv6 default gateway is set, and with no default gateway IPv6 addresses are not distributed on the LAN via SLAAC or DHCPv6.

Back in May 2021 I discussed this issue with Keenetic Support, and at last they suggested to run the command

interface PPPoE0 ipv6 force-default

After appliying this command the PPPoE interface is set as IPv6 default gateway and all devices start getting IPv6 addresses.

So, currently a CLI command is required in order to have a functional IPv6 setup.

I'd like request that Keenetic implemets one of the two following solutions:

1. Add a "Do not wait for RA" option, like pfSense does. This way the Keenetic router will not wait endlessly for a RA packet that will never arrive, and setup the default gateway autonomously.
2. Automatically set the default gateway as the PPPoE interface, or use the link-local address of the ISP router as gateway. This is what OpenWrt does, as I tested it on network contract.

I don't know if every ISP does not send RA packets via PPPoE, but I know of at least two ISPs in my country with this "problem". As of today checking the "Use IPv6" box in the PPPoE section of the Keenetic router does not result in a functional IPv6 setup, because an additional CLI command is required.