Date: Wed, 3 Feb 1999 22:52:43 +0800 (CST) From: Chia-liang Kao <clkao@CirX.ORG> To: wpaul@skynet.ctr.columbia.edu Cc: current@FreeBSD.ORG Subject: Re: problem with vr0 Message-ID: <199902031452.WAA43061@genius.cirx.org> In-Reply-To: <199902031426.JAA06705@skynet.ctr.columbia.edu> (message from Bill Paul on Wed, 3 Feb 1999 09:26:24 -0500 (EST)) References: <199902031426.JAA06705@skynet.ctr.columbia.edu>
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* From: Bill Paul <wpaul@skynet.ctr.columbia.edu> * Date: Wed, 3 Feb 1999 09:26:24 -0500 (EST) * * And you have your vr0 interface and your roommate's vr0 interface both * connected to this _same_ hub as well? (See, this is why I yell: I can see * how somebody might try this and not think that it might cause problems. * If I was right there looking at your systems I could probably spot this * immediately, but it was only blind luck that you happened to mention * it now, otherwise I could have spent months going back and forth with * you via e-mail before finally dragging this piece of information out * of you.) Certainly not, sorry that I didn't specify precisely. I meant we used the hub very well connecting us and the outside world, and then we decided to use the hub for internal connection only. So the hub is now connecting our vr0's and nothing else. (Of course, the power adapter is connected. :) * - Obtain (purchase/borrow/steal) a second hub, and connect all the * 192.168.100 interfaces to it all by themselves. * * - Connect your vr0 interface to your roommate's vr0 interface directly * using a crossover cable. (A crossover cable has the transmit and receive * pairs reversed on one end.) * * - Temporarily unplug your de0 interface and his ed0 interface from the * hub and leave just the vr0 interfaces plugged in. Use arp -d to remove * each others' ARP entries from your respective ARP caches so that we * start fresh. If you can successfully ping each other via the * 192.168.100 interfaces and exchange traffic, then you have found the * problem. (This is the easiest test, and it doesn't cost anything. :) We are poor students, so the easiest test has been performed right after we can't get the vr0s to work. (actually it's mine, his works very fine) We even swapped our cards and the result (the ping/trafshow test) is the same. Also, the vr0 currently on my box was originally his, and he used the card to connect outside world in the past. Shouldn't be a kernel issue, since I have tried to get it right by booting his kernel. Anyway, I'll try the first two tests tomorrow. (Ya, you know it, I'll steal one.) * > vr0 1500 <Link> 00.80.c8.ef.82.09 16 0 15804 0 0 * > vr0 1500 192.168.100 192.168.100.2 16 0 15804 0 0 * * Hm... No transmit or receive errors. I wonder what all the output traffic is * though. When I ping him, he can receive my packets and replies, while I can't get his reply. I think that's where th output packet came from. (ie the icmp outgoing packets when I ping him). And `netstat -in' on his box shows the input and output packets on vr0 are nearly identical. * Hm. Okay. Here's a slightly different test: * * # tcpdump -n -e -i vr0 & * # arp -d 192.168.100.1 * # ping -c 192.168.100.1 * # arp -d 192.168.100.1 * # ping -c 192.168.100.1 * * One possibility is that the receiver is getting stuck and has to be reset; * running tcpdump to put the interface in promiscuous mode implicity * reinitializes and resets the card (it happens that that's how the driver * works). In the above example, we initialize the card once and then leave * it alone, then run the arp -d/ping test twice. If you see the same exact * results both times (i.e. the chip receives at least one frame) then the * receiver is not getting wedged, since it would be receiving at least * two frames correctly without having to be reset. The difference of the above two arp -d/ping are: the first one have 3 `arp who-has' message and 1 arp reply and 3 icmp echo the second one have 5 `arp who-has' and 1 arp reply and 1 icmp echo To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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