Date: Mon, 31 May 1999 18:17:49 -0400 (EDT) From: Bill Paul <wpaul@skynet.ctr.columbia.edu> To: maret@axis.de (Alexander Maret) Cc: hackers@freebsd.org Subject: Re: xl driver for 3Com Message-ID: <199905312217.SAA04728@skynet.ctr.columbia.edu> In-Reply-To: <91DA20EC3C3DD211833400A0245A4EA9BA0E4D@erlangen01.axis.de> from "Alexander Maret" at May 31, 99 07:34:30 pm
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Of all the gin joints in all the towns in all the world, Alexander Maret had to walk into mine and say: > Hmm, > > I'm no expert and this all sounds reasonable to me, but there are > things I haven't mentioned yet: Grrr. What were you waiting for. You should have mentioned them to start with. > When I boot linux on my FreeBSD server and I transfer the same > 30MB of Data via Samba, I only get 4 (!) collisions (HalfDuplex). Well maybe FreeBSD is transmitting packets much faster than Linux. :) You still haven't actually measured the transfer speed, so there's no way for us to know. > The collisions are measured with the 3COM NIC-Doctor. > I don't know if I can trust the output of NIC Doctor but > I'm (as a newbie) highly alerted by the difference of those two > values. Anyway - I will try what you told me and look at the > leds and at the netstat output. I also would like to know > how I can set up my FreeBSD system to support Full Duplex. Grrr. This tells me that you may not understand what full duplex really means. You're not allowed to fiddle with the full-duplex/half-duplex setting like it's some performance knob that you can crank up to "make things work better." If all you have is a hub, then the hub only supports half duplex. You can't set the machines to full duplex if the hub is only half duplex. You'll get rotten performance. On the other hand, if you have a *switch* -- which is *NOT* the same thing as a hub! -- and the switch ports support full duplex operation (which most do), *then* you can set the hosts for full duplex. Usually though, switches support NWAY autonegotiation, which means the NICs should autodetect the fact that the switch supports full duplex and the switch port and the NIC will both agree to use full duplex automatically. You can also use full duplex if you wire the machines back to back with a crossover cable. As to how you set the interface to full duplex, there are man pages to read which will tell you that. Naturally, being a newbie, you feel you have a god given right to ignore the man pages and go rummaging around with your web browser chewing up bandwidth instead of reading the instructions right under your nose. If you read the ifconfig(8) man page and the xl(4) man page, you would learn that the right way to do it is: # ifconfig xl0 media 100baseTX mediaopt full-duplex > Another interesting thing: If i switch the my NT client to > FullDuplex and FreeBSD is in HalfDuplex mode then my > FreeBSD server resets immidiately. Grrr. I'm sorry, but I really don't think you're putting the pieces together correctly. Setting the NT machine to full duplex should have absolutely no effect on the FreeBSD host. It will completely screw up performance since the LoseNT host will then no longer be set to match the hub, but that's another problem. I strongly suspect that you're not making the proper observations when your problem manifests and just leaping to the conclusion that setting the LoseNT host to full duplex crashes the FreeBSD host. I don't think that's true. If both machines are sitting idle (not transmitting any data) and you just suddenly set the LoseNT host to full duplex, the FreeBSD machine isn't going to just say "Hey! The LoseNT host changed modes! I better crash now!" There must be more to it than that, but you're not going into any detail. Remember when I said I wanted *detailed* problem reports? This is why. How do we know there isn't some really explicit panic message on the console that's screaming: "I crashed because of the following reason: <foo>?" Maybe there's a message like that there, but we'll never know unless you tell us! So don't tell me "it resets immediately." Tell me *EXACTLY* what appears on the console (or if!) it crashes, word for word. Not your interpretation of what it says: *EXACTLY* what it says. And you still haven't explained what you meant about the LoseNT machine crashing before. -Bill -- ============================================================================= -Bill Paul (212) 854-6020 | System Manager, Master of Unix-Fu Work: wpaul@ctr.columbia.edu | Center for Telecommunications Research Home: wpaul@skynet.ctr.columbia.edu | Columbia University, New York City ============================================================================= "It is not I who am crazy; it is I who am mad!" - Ren Hoek, "Space Madness" ============================================================================= To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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