Malcolm Beattie wrote:
>
> Philip Hazel writes:
> > On Mon, 19 Apr 1999, david sims wrote:
> >
> > > woohoo! it's working! I finally figured out that I had to make two
> > > changes in config.h.defaults:
> > >
> > > #define DELIVER_IN_BUFFER_SIZE 512 /* was set to 8192 */
> > > #define DELIVER_OUT_BUFFER_SIZE 512 /* was set to 8192 */
> > >
> > > Then I recompiled, and my mail started going out to mail.earthlink.net
> > > again.
> >
> > My goodness. That seems extremely odd.
[snip]
> I haven't followed the thread but these symptoms smell like an
> all-too-common problem where some firewall or router between him and
> his destination wrongly drops all ICMP packets. This breaks the
> "Path MTU discovery" system used by most modern TCP implementations
> and causes symptoms where small packets get through but large ones
> don't.
ok, at Philip's suggestion, I did some further digging. It turns out
that my ISP, Earthlink, wants an MTU of -- guess what -- 512. I don't
know why my PPP connection wasn't negotiating this correctly. It's
always worked fine on my Win98 and WinNT boxes. So I changed
/etc/ppp/options to have an MTU of 512 and ran pppconfig, and
everything's been working fine since. To make sure pppconfig didn't fix
the problem, I commented out 'mtu' in /etc/ppp/options and duplicated my
error.
Malcolm's observations seem to make sense. It would seem that something
isn't configured right at Earthlink. However, I still don't see why I
never saw this problem from Win98 and WinNT boxes. Then again, I wasn't
running exim on those boxes, which seems to have triggered the problem.
So, I'm able to return to the stock Debian exim program now. All my mail
-- large and small -- is going out immediately to my smarthost.
Thanks to James, Jeffrey, Malcolm, and Philip for your help. I have to
say that exim is much more of a pleasure to deal with than smail,
sendmail, and all the other MTAs I've tried.
cheers,
david
--
david sims
david@???
www.simscomputing.com
--
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