Re: High latency for IPv6 on netbsd-8

[Roy Marples <roy%marples.name@localhost>]

On 29/07/2018 17:05, Gua Chung Lim wrote:
> Thanks for your kind response.
>
> * Martin Husemann (martin%duskware.de@localhost) wrote:
> > In the not working case, wm0 has:
> >
> >    inet6 2405:9800:b550:2939:f234:69d6:e0bf:8ebf/64 flags 0x0
> >    inet6 2405:9800:b550:2939:8638:35ff:fe48:5720/128 flags 0x0
> >
> > and it would be good to understand where the second comes from.
> > Maybe add "-d" to dhcpcd_flags in /etc/rc.conf and see what it
> > says?
> -d flag when ping6 is NOT working,
> Excerpted from /var/run/rc.log.
> https://pastebin.com/JXkKxuSc
>
> -d flag when ping6 is working,
> # /etc/rc.d/dhcpcd stop
> (then leave it 5-6 seconds)
> # /etc/rc.d/dhcpcd start
> https://pastebin.com/iu4utd9y
>
> % uname -a
> NetBSD netbsd 8.0_STABLE NetBSD 8.0_STABLE (GENERIC) #1: Sat Jul 28 08:47:57 +07 2018  root@netbsd.localdomain:/usr/obj/sys/arch/amd64/compile/GENERIC amd64
>
> For now, my only workaround is to repeat restarting the router until ping6 works, and without touching any configuration on netbsd-8. I don't suspect my router, as the other machines on the same LAN (including the previous netbsd-7) are still working pretty fine. I don't suspect dhcpcd as both inet and inet6 got assigned. And I don't suspect name resolution as it can always interpret canonical names into numeric addresses for both inet and inet6.
>
> Any ideas?

rc.log will only log what happens until dhcpcd forks.
In the first log, dhcpcd forks when the DHCPv6 DaD completes. This would 
be due to the RA not carrying a RDNSSL option.
The the second log, dhcpcd forks when the right away because DaD has 
already completed on the existing address. We've not yet received an RA 
at this point.

You'll get better information either by trawling syslog, or by adding 
`logfile /var/log/dhcpcd.log` to dhcpcd.conf.

Hopefully you'll see the same debug written - just maybe not in the same 
order due to randomised delays.

Roy