feature wish: --block-ipv4

[cron2]

I've been speaking to people that want to move to ipv6 only inside their networks, and their VPNs.

This brings up the same problem we had with ipv4 only + redirect-gateway VPNs and clients trying to access dual-stack hosts - "the other protocol" will then leak out to the Internet (assuming dual-stack on the client ISP for a long time).

Thus, we need --block-ipv4 with similar semantics as --block-ipv6...

(Note: whether or not --block-ipvX should also auto-enable --redirect-gateway <x> is up for discussion, but it needs to be consistent between IPv4 and IPv6)

[cron2]

10:42 < dazo> and ... Core/3 has --block-ipv4 too ....