Subject: Re: IPv6 PMTUD broken
To: None <itojun@iijlab.net>
From: Ronald van der Pol <Ronald.vanderPol@rvdp.org>
List: tech-net
Date: 06/04/2004 08:26:38
On Fri, Jun 04, 2004 at 12:34:11 +0900, itojun@iijlab.net wrote:

> >This is reproducable now:
> >- delete host route
> >- start named
> >- send dns query 
> >- dns reply is sent with > 1280, no action on icmp6 packet too big
> >(host route is present)
> >- send dns query 
> >- dns reply is sent with > 1280, no action on icmp6 packet too big
> >- restart named
> >- send dns query
> >- dns reply with <= 1280, OK
> 
> 	hmm.  do you see anything weird on netstat -sn?  i guess you have
> 	something weird in icmp6 section.

(sorry, I was in suspend mode, timezones)

I have done the things above on NetBSD kirk.rvdp.org 1.6.2_STABLE. The
same thing happens.

This is on NetBSD bones.rvdp.org 2.0F:

bones.rvdp.org$ netstat -sn -p icmp6
icmp6:
        7 calls to icmp6_error
        0 errors not generated because old message was icmp6 or so
        0 errors not generated because of rate limitation
        Output packet histogram:
                unreach: 7
                echo: 23
                echo reply: 2
                multicast listener report: 10
                router solicitation: 3
                neighbor solicitation: 121
                neighbor advertisement: 209
        0 messages with bad code fields
        0 messages < minimum length
        0 bad checksums
        0 messages with bad length
        Input packet histogram:
                unreach: 3
                packet too big: 131
                time exceed: 21
                echo: 2
                echo reply: 23
                router advertisement: 376
                neighbor solicitation: 209
                neighbor advertisement: 118
        Histogram of error messages to be generated:
                0 no route
                0 administratively prohibited
                0 beyond scope
                0 address unreachable
                7 port unreachable
                0 packet too big
                0 time exceed transit
                0 time exceed reassembly
                0 erroneous header field
                0 unrecognized next header
                0 unrecognized option
                0 redirect
                0 unknown
        2 message responses generated
        0 messages with too many ND options
        0 messages with bad ND options
        0 bad neighbor solicitation messages
        0 bad neighbor advertisement messages
        0 bad router solicitation messages
        0 bad router advertisement messages
        0 bad redirect messages
        11 path MTU changes
bones.rvdp.org$ 

You cannot reproduce this? I could try again later with a GENERIC_LAPTOP
kernel. Anything else I could try to pinpoint this?

	rvdp