On Thu, Jul 03, 2003 at 05:21:13PM -0700, Wayne Lubin wrote:
> 
> --- Matthew Seaman <[EMAIL PROTECTED]>
> wrote:
> > On Thu, Jul 03, 2003 at 10:50:12AM -0500, Matthew
> > Bettinger wrote:
> > > On Thursday 03 July 2003 10:44 am, Matt Heath
> > wrote:
> > > > >I've had a recurring issue with Mozilla and
> > Firebird (was Phoenix):
> > > > >The browsers will stall in a seemingly
> > non-deterministic fashion.
> > > >
> > > > I get that too
> > > 
> > > My mozilla will hang for a few minutes when I
> > enter a url in the 
> > > location bar.  If I fire it up and click on the
> > link that are already 
> > > there it's fine.  The moment I try to type a new
> > URL in the bar it just 
> > > hangs.  I am using the nvidia drivers on bsd 4.8. 
> > Never had a problem 
> > > (that I can recall) until I installed the nvidia
> > drivers..  could be 
> > > wrong tho.  
> > 
> > I you go into Mozilla preferences, under Advanced :
> > Keyboard
> > Navigation and disable Find As You Type, then you'll
> > avoid the several
> > minutes of hang the first time you try and type into
> > a text field or
> > the location bar.  Presumably the same trick would
> > work with Firebird,
> > but unfortunately there doesn't appear to be a
> > control for disabling
> > that "feature".
> > 
> > I don't think this has anything to do with the video
> > hardware or
> > drivers you're using -- I guess that was just a
> > coincidence.  You must
> > have installed or upgraded Mozilla around the same
> > time.  This pausing
> > thing was introduced around the same time as Mozilla
> > 1.3 was released.
> > It's not just FreeBSD that suffers either.  There
> > have been bug
> > reports in Mozilla's Bugzilla DB for some time, but
> > the problem still
> > persists.

> there is no preferences >  Advanced :
>  Keyboard Navigation option in my mozilla preferences
> 
> I am using mozilla-1.0.rc3,1 whatever that means :).

Your mozilla is too old to have the bug that Matthew Bettinger
reported.  However, from your other postings you're running into a
different issue.  Mozilla uses the standard FreeBSD gethostbyname()
implementation to convert host names into IP numbers.  Nowadays, this
involves attempting to find an IPv6 address -- as the standards say
should be done.  Now, most of the time, the resolvers in question will
simply respond "not known" when asked for an AAAA or A6 record.  The
lookup will then proceed onto retreiving the IPv4 A records as per
usual.  The problem occurs when you run into certain broken DNS
resolvers that don't understand IPv6 at all, and not only that, they
don't even respond at all to a query for a record type they do
recognise.  That means your system has no option but to hang around
waiting for a minute or so untill the query times out and it can
assume that no reply is ever going to appear.

This isn't really a bug in Mozilla -- it's a bug in the DNS servers
that don't respond according to the DNS RFCs.  However, there are
various things that can be done to ameliorate the problem from the
user side.  My preferred option is to observe that the vast majority
of offenders are actually the sites that put banner adverts on pages.
Right clicking on the adverts and selecting "Block images from this
server" goes a long way to improving the web experience, and it sends
the message to the advertizers "fix your DNS servers" in the sort of
language they cannot afford to ignore.

Alternatively, you can compile your whole system without IPv6 support,
by removing:

    options INET6

from your kernel config.  There's probably some other flags you could
set to strip IPv6 support out of other applications in the sources,
but I don't think there is a general knob to turn it off everywhere.
This options is undesirable IMHO -- why strip out working new
functionality from your system for the convenience of some dinosaurs
who can't keep up with changes in the Internet standards that have
been in play for getting on for nearly 10 years? -- see
http://www.faqs.org/rfcs/rfc1886.html

If you're interested in this sort of thing, see
http://www.faqs.org/rfcs/rfc3364.html for a good discussion of the
pros and cons of various methods of IPv6 support in the DNS

        Cheers,

        Matthew



-- 
Dr Matthew J Seaman MA, D.Phil.                       26 The Paddocks
                                                      Savill Way
PGP: http://www.infracaninophile.co.uk/pgpkey         Marlow
Tel: +44 1628 476614                                  Bucks., SL7 1TH UK

Attachment: pgp00000.pgp
Description: PGP signature

Reply via email to