[00:02] <blackboxsw> +1 I'll probably have to continue this conversation tomorrow. pulled into dinner stuff. thx all.
[00:29] <blackboxsw> drive by ec2 ipv6 note as well: the time cost wasn't crawling the ipv6 imds. it was the sandboxed dhcp4 dhclient run 
[00:29] <blackboxsw> 2022-01-27 22:54:02,127 - subp.py[DEBUG]: Running command ['/var/tmp/cloud-init/cloud-init-dhcp-py2u27z4/dhclient', '-1', '-v', '-lf', '/var/tmp/cloud-init/cloud-init-dhcp-py2u27z4/dhcp.leases', '-pf', '/var/tmp/cloud-init/cloud-init-dhcp-py2u27z4/dhclient.pid', 'ens5', '-sf', '/bin/true'] with allowed return codes [0] (shell=False, capture=True)
[00:29] <blackboxsw> 2022-01-27 22:54:05,456 - util.py[DEBUG]: All files appeared after 0 seconds: ['/var/tmp/cloud-init/cloud-init-dhcp-py2u27z4/dhclient.pid', '/var/tmp/cloud-init/cloud-init-dhcp-py2u27z4/dhcp.leases']
[00:30] <blackboxsw> 3.5 second delay between invoking that dhclient and getting a response on ipv6-only instances :)
[00:33] <minimal> blackboxsw: you're reminded me of another relevant comment to make re: IPv6 - dhclient only supports IPv4 or IPv6 (so to do both you're need to run 2 instances). Have you considered support for dhcpcd which can do both in the same instance?