Re: High latency for IPv6 on netbsd-8

[Gua Chung Lim <gua.chunglim%gmail.com@localhost>]

Thank you for all your responses.
And sorry for my late reply.
At work I use FreeBSD.
I only use NetBSD at home (and at my own will).
So during office hours, I can't test NetBSD.
I can test NetBSD only at the night time (UTC+0700).
I can ssh from FreeBSD at work to NetBSD at home.
But I just can't restart the router from there.

* Robert Elz (kre%munnari.OZ.AU@localhost) wrote:
>   | > tcpdump -s 2000 -w DUMP-FILE -i wm0
>   | It gave me a binary log. But how to read it?
> tdpdump -s 2000 -r DUMP-FILE   (that was in the earlier message).
Thank you.

>   | > ping6 -n 2001:3c8:9007:1::21 (munnari.oz.au - one of its addresses)
>   | I shall ping6 between 3:00-4:00pm GMT.
> 
> Sorry, it is now 16:xx UTC and I only just saw this e-mail - that was
> just after 16:00, since then I have been building this reply (Iwas away
> from my keyboard for a couple of hours earlier.)
> 
> I will do a tcpdump just like above.   Then you tell me what time you tried
> and it failed, and I'll check what was happening at that time.
> 
> But I'd appreciate a smaller window than an hour if possible, that would
> make a VERY big dump file if I just capture everything, and I would prefer
> not to filter too much (except I can limit it to v6) in case that causes a 
> false negative (if my filter caused my tcpdump not to save your packets...)
I have to find the other ways around.
I don't want bother you, indeed.
My time and yours should not match each other.
I may probably reinstall NetBSD 8.0 anew from dvd.
But I shall still keep this disk slice for testing for some time.
Thank you for your kind support.

>   | > I could also try a ping6 from here to your host if I know more or less
>   | > exactly what time to do it (when your host has just rebooted and things
>   | > are not working as they should).
>   | Do you mean pinging my router or my host? My host sits behind NAT.
> 
> NAT for IPv6 ?   Why?    There's no point checking IPv4, that's working,
> right?
> 
> If you are really attempting IPv6 NAT for some weird reason, stop...
Hmm, maybe I get you wrong. I have to explain something more.
Since IPv4 has already exhausted in my area, the address given from my ISP is completely IPv6 (no 6bone, no HE, etc). So the router has the real public IPv6 address. But my local network is still IPv4. But apparently, the router is v6 so each host in my internal network also has its own IPv6 address assigned from the router. It is a simple home network, the router is also acting dhcp server, switch and gateway.

>   | Or shall I forward the port from router to my host?
> ICMP has no ports.   So that's not possible.
Exactly,

>   | (I remember when I was using 6bone, anyone can ping6 me behind LAN without port forwarding.)
>   | Anyway my host is 2405:9800:b550:2939:f234:69d6:e0bf:8ebf/64
>   | or 2405:9800:b550:2939:8638:35ff:fe48:5720/128 and
>   | my router is 2405:9800:b550:2939:8ee1:17ff:fe1f:d1c7.
> 
> Right now I cannot get to you at all (what is the router's V6 address on the
> interface facing the internet) ?
My router's public v6 address is 2405:9800:b550:2939:fce8:7cf3:45d:837e.
But I'm not always on, since my NetBSD is running on my notebook.
I shouldn't keep it on all the time.

> I see nothing very revealing there - just that when it is failing the IPMPv6
> echo packets being sent is going up (it seems, with just one output it is
> hard to be sure) but no replies are coming back (and that when it is
> working you are getting replies).    That all looks like  the host is doing
> what it should, and most likely the problem is elsewhere (at the router,
> or further into the internet).
That's what I am finding.

> If you can use some other host on the same LAN, and send ICMPv6 pings
> from it, which work, at the same time (or very close) to when pings from
> the NetBSD-8 host are failing, that would be useful info.   If that works,
> the IPv6 address of that host would be useful to know as well.
I tested it many times. While ping6 on netbsd-8 is failing, the other hosts on same network are still ping6(ing) fine.

>   | % tail -n 2 /etc/dhcpcd.conf
>   | logfile /var/log/dhcpcd.log
>   | nodhcp6
>   | Now ping6 is usable even if DHCP6 is disabled entirely.
> 
> Are you saying that with that config it works, or that it does not work ?
Sorry to make you confuse. With this config, there is nothing different. I still have to keep restarting the router. By the way, I have to say that I am a C instructor (mostly ANSI C). I have very limited knowledge about sys admin. At work, somebody else do it for me. I only know about algorithm kinda data structures or Big-O notation and the like. I thought that disabling DHCP6 would drop RS and refuse RA from the router. And I did wonder, even if it was dropped, ping6 occasionally worked.

>   | No, it was using dhcpdc and rtsol on -7.
>   | I haven't used dhclient for long, probably -5.
> 
> Oh sorry, obviously I misinterpreted when you said you would try
> "going back to dhclient" (which I do not think would help anything.)
No problems, :-)

* Roy Marples (roy%marples.name@localhost) wrote:
> > It seems likely. Please tell me the old and new file locations.
> 
> Old locations:
> /etc/dhcpcd.duid
> /etc/dhcpcd.secret
> 
> New locations:
> /var/db/dhcpcd/duid
> /var/db/dhcpcd/secret
It seems ok to me.
% ls -1 /etc/dhcpcd.duid /etc/dhcpcd.secret
ls: /etc/dhcpcd.duid: No such file or directory
ls: /etc/dhcpcd.secret: No such file or directory
%
% ls -1 /var/db/dhcpcd
duid
secret
vioif0.lease
vioif0.lease6
wm0.lease
wm0.lease6
wm1.lease

> > > You can add `nodhcp6` to dhcpcd.conf to disable DHCP6 entirely.
> > I have done it.
> > % tail -n 2 /etc/dhcpcd.conf
> > logfile /var/log/dhcpcd.log
> > nodhcp6
> > Now ping6 is usable even if DHCP6 is disabled entirely.
> 
> Does this imply that it's all now working for you?
Nope. Sorry to make you confuse. Please see above.

-- 
Gua Chung Lim
 
"UNIX is basically a simple operating system,
but you have to be a genius to understand the simplicity."
-- Dennis M. Ritchie