* marka@isc.org (Mark Andrews) [Tue 19 Jun 2018, 01:35 CEST]:
If you filter 2002::/16 then you are performing a denial-of-service attack on the few sites that are still using it DELIBERATELY.
Find me one site with a competent admin that deliberately publishes 2002::/16 in DNS.
None of the problems required removing it from BGP. There were end sites that had firewalls that blocked 6to4 responses and the odd site that ran a gateway and failed to properly manage it. The rest could have been dealt with by configuring more gateways.
Could. But hasn't. Right now it's merely a security risk. People who used to run a gateway and competently managed it took them down years ago when they, being competent admins, realised the utility had run out. -- Niels.