ps: one thing that would be good though, and which would
help, would
be for dhcpcd to avoid adding a default v6 route if there are no
available v6 addresses (link local excepted, as they can't use the
route anyway). Until now I wasn't sure if dhcpcd was adding that,
or the kernel, when an RA arrives. But I see ...
Apr 10 08:53:16 jinx dhcpcd[14261]: iwm0: Router Advertisement from fe80::c0ea:b0ff:fe55:6190
Apr 10 08:53:16 jinx dhcpcd[14261]: iwm0: adding default route via fe80::c0ea:b0ff:fe55:6190
I am not sure why that causes problems, with no available useful v6
addr any attempt to send to destination v6 addrs should immediately
fail - but it does make a difference, stuff like connections
to *.netbsd.org go much slower (that is, connect much slower) when
that default route exists - after I delete it, the v6 attempt immediately
fails, and fall back to v4 happens immediately (and that works). The
ideal solution would be for my ISP to support v6, but that one I cannot
control..... (and yes, I know I could set up a tunnel).