From mboxrd@z Thu Jan 1 00:00:00 1970 From: bob@kunk.jriver.com Message-ID: <19990808175727.19320.qmail@kunk.jriver.com> Subject: Re: Odd iMac ethernet problem In-Reply-To: <199908060541.PAA20067@tango.anu.edu.au> from Paul Mackerras at "Aug 6, 1999 03:41:18 pm" To: Paul.Mackerras@cs.anu.edu.au Date: Sun, 8 Aug 1999 12:57:27 -0500 (CDT) CC: linuxppc-dev@lists.linuxppc.org MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: User Paul Mackerras says: > bob@kunk.jriver.com wrote: > > > When the iMac talked to either Unix box from linux-ppc (several kernels > > tested), I would get nearly 100 percent on receive but REALLY slow > > response on transmit (like about 40k/sec). Watching the lights on the hub, > > it appears that there is a really big delay restarting transmit after > > a collision occurs. Perhaps duplex set wrong? > > I have seen this too but I haven't figured out what's going wrong yet. > My suspicion is that some packets are getting corrupted somehow on > transmission and then we are having to wait for a TCP retransmit. A > tcpdump might yield some interesting information. I haven't got tcpdump setup on another linux box yet but I did borrow a 10/100 NWay switch from work and tested the 4 speed/duplex combinations. The iMac transmits properly only on 100mb/half duplex (860 k/sec, it's talking to a redhat i386 linux box on 10mb on another switch port). All the rest of the combinations are 60k/sec or less on transmit. Hopefully I'll have time to do a packet trace this evening. Bob -- Robert E. Brose II N0QBJ http://www.jriver.com/~bob/ bob@kunk.jriver.com [[ This message was sent via the linuxppc-dev mailing list. Replies are ]] [[ not forced back to the list, so be sure to Cc linuxppc-dev if your ]] [[ reply is of general interest. Please check http://lists.linuxppc.org/ ]] [[ and http://www.linuxppc.org/ for useful information before posting. ]]