add IPv6 support

Now that the port to nftables has been completed, it’s time to add IPv6 support.

Suggestions which internal IPv6 addresses we should use for,

  • A) Whonix-Gateway internal network interface?
  • B) Whonix-Gateway external network interface?
  • C) Whonix-Workstation internal network interface?

I plan to keep using static IP configuration without introducing the complexities of DHCP.

related source code files:

related, on why we use for IPv6:

This is for Non-Qubes-Whonix only. For Qubes-Whonix, there is a separate ticket: add IPv6 support to Qubes-Whonix · Issue #9267 · QubesOS/qubes-issues · GitHub

Should consider using unique local address (ULA).