I did have to disable autonegotiation, but that didn't resolve the problem
either. It did eliminate the "late collisions" and "FDS errors" which are
systematic of duplex mismatch.
Turns out it must not be the switch. I've connected two machines directly
with a crossover cable and it still has the same long delay (~1mbps, vs.
10mbps or 100mbps).
They are TULIP (10/100) Ethernet Interface (on a DEC Alpha 566, running
Digital Unix 4.0b with jumbo patch of 7/1/98).
Does Dunix need to be told it's 100mbps? The ewa0_mode is set at boot
level to force 100mbps half or full duplex. I've tried both and both are
the same. All I can think of next is to bump them down to 10mbps and see
what happens, but in the end we need 100mbps...
I've tried both nfs copies and ftp of non nfs partitions.
Seems fine though with the same nfs mounted and ftp from one of these
machines to and from a 10mbps machine.
Any thing else to recommend?
>The predominant suggestion was to check/force the duplex on the machine and
>on the switch to either full or half duplex. I tried it both ways,
>disabling the port, setting to half or full on both sides, then reenabling
>the port.
>all I have in /etc/rc.config for IFCONFIG_0="<machineip> netmask
255.255.255.0"
>so I tried changing the duplex at boot level
>
>I tried all combinations... at boot level, the machines had ewa0_mode FastFD
>and the switch was set at auto-negotiate which selected half duplex. Ok...
>so just change it right?
>I tried explicitly telling the switch to use full duplex... same problem
>I tried explicitly telling the machine and the switch to do half duplex...
>same problem
>And disabled ports before change, and enabled after change. Even tried a
>powerdown.
>I don't expect it's the cables (cat 5, 1meter) since they transfer 5-10x
>faster to 10mbps machines.
>
>I realize cpu/disk speed may result in a greater bottleneck than the
>switch/network, but it should at least approach the performance of the same
>file from a 10mbps machine. I've tried it with both nfs copies, and with
>ftp (eliminating the cause of an nfs problem?).
>netstat -i shows virtually no Ierrs Oerrs or Coll. "monitor" also didn't
>show anything strange.
>
>Still scratching my head...
>
>Here's the original thread...
>
>>Ok... we have a bunch of servers... 3 of which are 100mbps and 6 are 10mbps.
>>Here's the times of nfs copy/ftp of a ~3.5mb file
>>
>>10mbps machine --> 10mbps machine 4.3 sec
>>10mbps machine --> 100mbps machine 7.6 sec
>>100mbps machine --> 10mbps machine 5.6 sec
>>100mbps machine --> 100mbps machine 142.5 sec ----WHY?!
>>
>>I think i've ruled out nfs problems since all machines are using automount
>>and all are mounted using 2mb read/write cache (I've tried disabling cache
>>too).
>>They are all on the same subnet and same Cisco 2916 10/100 switch, and
>>settings on the switch are pretty much default set when it comes out of the
>box
>>the 100mbps machines are set at eprom to do 100mbps, and the switch
>>autoconfigures as 100mbps, half duplex
>>
>>I don't think the gateway is the problem since they are all on the same
>>subnet but how does a machine determine which of 2 gateways to use? All
>>machines are running /usr/sbin/gated and most or all don't have a
>>/etc/gated.conf or /etc/gateways file
>>
>>one 100mbps machine's ifconfig tu0:
>>tu0: flags=c63<UP,BROADCAST,NOTRAILERS,RUNNING,MULTICAST,SIMPLEX>
>> inet 128.230.57.16 netmask ffffff00 broadcast 128.230.57.255 ipmtu 1500
>>
>>one 10mbps machine's ifconfig ln0:
>>ln0: flags=c63<UP,BROADCAST,NOTRAILERS,RUNNING,MULTICAST,SIMPLEX>
>> inet 128.230.57.3 netmask ffffff00 broadcast 128.230.57.255 ipmtu 1500
>>
>>Any other ideas of why the 10x difference or something I may be missing?
>>
--------------------------------------------------------------------------
Dan Kirkpatrick dkirk_at_phy.syr.edu
Computer Systems Manager
Department of Physics
Syracuse University, Syracuse, NY
http://www.phy.syr.edu/~dkirk Fax: (315) 443-9103
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Received on Wed Apr 28 1999 - 16:06:58 NZST