Hi Martin,

> Yeah I know what you mean.
> My thoughts are that unix boxes don't dynamically build an arp table for
> their segment. they only look on bootup or when somebody
> broadcasts looking
> for a connection via the hosts file.
> Microsoft netbios (aka  Lan Manager) does chatter endlessly. Though this
> does ensure arp tables are up to date on that particular ethernet
> segment it
> does hog bandwidth by endlessly broadcasting .
> Get your sysop to do a bit more reading and use SAMBA on your
> unix boxes to
> fake netbios.
> Am I wrong ?
> Martin

That's an interesting idea although if the workaround simply requires more
chatter having ping run periodically seems a little easier. In any case, it
helps to have a decent theory of why Windows isn't having this problem.

cheers,
::mark


>
> ----- Original Message -----
> From: "Pierre Fortin" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Saturday, October 05, 2002 2:18 PM
> Subject: Re: [expert] networking wackiness
>
>
> > On 05 Oct 2002 00:09:39 -0700 James Sparenberg <[EMAIL PROTECTED]>
> > wrote:
> >
> > > On Thu, 2002-10-03 at 08:10, Mark Stewart wrote:
> > > >
> > > > Networking gurus, your knowledge is desperately needed...
> > > >
> > > > I have my Mdk8.2 box setup on our corporate network with a static
> > > > IP. Call it mybox.foo.com. I have a laptop running Win2K that lives
> > > > on our wireless LAN and uses a DHCP-allocated IP and lives in a
> > > > subnet. Call it laptop.dhcp.foo.com. The trouble is that unless I
> > > > first ping the laptop from mybox, I cannot reach mybox from the
> > > > laptop. More problematically, if I leave an ssh connection from the
> > > > laptop to mybox idle for more than say 5 minutes the connection
> > > > dies. If I reboot into Win2K on mybox I don't have to ping first to
> > > > allow the laptop to connect and connections once made continue to
> > > > work for as long as you like. It just works.
> > >
> > > Had this problem about 2 years ago with an ALL FreeBSD/Win98 network.
> > > with 7 mini-lans in different rooms of our office we noticed that
> > > boxes kept dropping off the net... but never the windows ones.  Turned
> > > out that the problem was because FreeBSD and we later found Linux as
> > > well don't keep "chattering" over the net and the Hubs (all switched
> > > 10/100 hubs) kept "losing" the boxes.  We'd have to do two way pings
> > > to get the FreeBSD boxes back up every morning...(do a tcpdump
> > > sometime when the network is quite and you'll see your windows boxes
> > > chattering away.)
> > >
> > > The solution.  a little script that did 3 pings to the firewall.
> > > Slept for 15 minutes and then did 3 pings again.
> >
> > James,
> >
> > That's a "workaround"...  :)  the solution is to have the bug fixed...
> > Don't have time to pull up the specs; but any packet for which there is
> > no MAC-to-output-port mapping is to be "flooded" out all ports.  If this
> > is not done by a particular switch box, or VLAN, it's a bug.
> >
> > [Sidebar:  similar effect occurs when the bridge/switch/VLAN tables are
> > smaller than the number of boxes directly connected -- I call this a
> > "leaky" <foo> box...  It's an interesting mental exercise to understand
> > this... :^) ]
> >
> > > Not all of the switched hubs did this (the 3coms for example) but some
> > > of the NetGear and lynksys ones did.
> >
> > NetGear (others?) ships dumb hubs (real ones, not switches labelled
> > "hub") with out-of-spec* crystals which can produce a similar symptom,
> > excect that the problem affects only long packets.
> >
> >   *   +/- 0.001%  i.e., 1000Hz for 10MHz
> >
> > LinkSys have an isolated development group that won't listen to customer
> > complaints.
> >
> > Pierre
> >
> > > James
> > >
> > > >
> > > > Our LAN admin, who clearly knows much more about Windows, is
> > > > pointing the finger at the OS since he isn't required to support
> > > > Linux. Our network has a bunch of VLANs in it, the details to which
> > > > I am not privy but if there's something that might be relevant I can
> > > > ask him about it. On the other hand, if anyone understands what's
> > > > going on here that has to do with how I've got mybox configured I
> > > > would really love to know. Just to be clear, I'm not running any
> > > > firewalls or anything, no iptables, ipchains, etc. I am running NFS,
> > > > Samba, ssh, and proftpd.
> > > >
> > > > Thanks in advance for any and all thoughts,
> > > >
> > > > ::mark
> > > >
> > > >
> > > > ----
> > > >
> > >
> > > > Want to buy your Pack or Services from MandrakeSoft?
> > > > Go to http://www.mandrakestore.com
> > >
> > >
> > >
> > >
> >
> >
>
>
> ------------------------------------------------------------------
> ----------
> ----
>
>
> > Want to buy your Pack or Services from MandrakeSoft?
> > Go to http://www.mandrakestore.com
> >
>
>
>


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