Two fiber connections coming inside my home. One is a home connection with a router that sends ipv6 to any machine that asks for it (which i may not always want), the other one is a business connection that goes into an Ubuntu router that has to run pppoe.
The path of least resistance with ipv4 was to have static ips for every PC and change the default route where I cared about which connection the PC used. Also was using the dhcp from the home router.
Now ipv6 has addresses that are auto generated by the OS on boot, addresses that are forwarded from the router and are in a subnet assigned to home ISP #1, and ... whatever I'd need to assign manually?
It's still hobbyist level not enterprise level if you ask me. But it's a lot to read for a network that works just fine thank you.