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
----- 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 >
Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
