Subject: Re: can't contacted www.netbsd.org
To: None <firstname.lastname@example.org>
From: Matt Doughty <email@example.com>
Date: 02/11/2004 04:58:46
On Wed, Feb 11, 2004 at 04:21:51AM -0500, der Mouse wrote:
> I can't be sure, of course, but my guess is that your broadband
> connection is PPPoE based and something between you and www.netbsd.org
> (perhaps even your linksys, especially if it's also a firewall) is
> dropping the ICMPs which drive path MTU discovery. The symptoms look
> very similar to what I saw when I was behind a low-MTU link. I would
> hope that the NetBSD servers aren't behind such broken "firewall"
> boxes, but maybe they are, now, or maybe something closer to you is
> dropping the ICMPs - or, for all I know, maybe the box on the other end
> of your broadband connection is so severely broken as to be dropping
> the packets but _not_ sending back the ICMPs.
> Try configuring the MTU on your Ethernet to be 1400 instead of 1500.
> This will normally make NetBSD send an MSS option specifying the lower
> limit; the peer will normally obey this, thereby papering over the
Well, I think you are probably right, but I have tried changing the MTU
and it didn't make a difference. That was what made me start looking
> > what doesn't work:
> > traceroute to anywhere (traceroute works from the windows box, but not the
> > solaris and *bsd boxes)
> Did you try traceroute -I? I think the equivalent is the default for
yep, with the -I traceroute worked like a charm.
> When you say traceroute "doesn't work", what do you mean? It dumps
> core? It prints nothing but stars? It gets partway and stops? I'd
> say there's a good chance that the point at which traceroute stops
> seeing stuff coming back is the point responsible for the other
> trouble. I also suspect it's a firewall configured by some
> over-paranoid admin who didn't really understand what certain packets
> are for.
I was getting nothing but stars. after the first hop.
It seems to be stopping at the pppoe unit from the ISP. I wonder why the
other boxes are still able to access the site despite this breakage.
I'm not sure where to go from here. Thanks for the help guys. Atleast,
I have some idea of where I should look.