Do you mean you turn off IPv6, because it's easy for others to get lots of IPs and bypass a IP blacklist?

If so, that is a difference from IPv4. Don't block IPs, block subnets. Block the whole /64. It's what you were doing with IPv4 anyway - blocking a whole building / office / etc at once!

That's still no reason to turn IPv6 off in my humble opinion...

IPv6 ratelimiting can be a bit tricky, you block my /64 and I come back with a /48 and so on.

Most stuff defaults to bucketing by /64s.

Right, but how does this differ from IPv4? Every time I restart my cable modem, I get a new IP from a /18 or so of IPv4 space.

IP blocking is far from ideal, in both versions of IP.. IPv6 makes this no better, or worse.

You get a single IP, that doesn’t scale well at all.

Please do not disable IPv6.

Disagree. If you've only got IPv4 experience and have a number of possibly legacy devices on your network, then there is a significant amount of learning and changes required to make it work with IPv6 (securely).

It's entirely reasonable to say "It works fine without [=zero business value], no need to invest that amount of work.". This makes IPv6 a negative value proposition for many orgs.

It depends on the context.

I mostly focus on users of VPN services. It's still rare for them to handle IPv6 traffic. So if you have IPv6 connectivity, IPv6 will leak, bypassing the VPN. Unless you have firewall rules, or disable IPv6 while using the VPN.