excessive/bizarre collision rate

excessive/bizarre collision rate

Post by Luke » Wed, 01 Mar 2000 04:00:00



On my 3 node lan I have a linux server (call it X) and two windows 98
clients (call them A and B) all wired into one hub.  All the hardware is
10Mbps and as far as I know, all cards are in half duplex.

If I connect to X from A via ftp, and upload a file from A to X, the
collision light on the hub is lit almost constantly, and I only get
about 6.5Mbps.  If I download a file from X to A via ftp, I get the same
results.

If I transfer a file from B to A via windows' file sharing mechanism,
the collision light blinks very rarely and I get about 6 Mbps.  However,
if I transfer a file from A to B using the saming method, the collision
light is almost constantly lit again and the speed drops to about
4.5Mbps.

I can't figure out what the slowdown is from, and it is kind of annoying
because I rely on a fast internal ftp connection to make backups of
certain large media files on the client computers. (I don't want to mess
with samba).

I get the feeling it is hardware, but I'm not sure.  Here are some
statistics from the internal card on the server after I uploaded some
large files to it via ftp from an internal computer.

eth1      Link encap:Ethernet  HWaddr 00:A0:24:4D:14:BA
          inet addr:192.168.0.1  Bcast:192.168.0.255  Mask:255.255.255.0

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:761055 errors:635 dropped:0 overruns:544 frame:635
          TX packets:605468 errors:0 dropped:0 overruns:0 carrier:0
          collisions:6118 txqueuelen:100
          Interrupt:7 Base address:0x300

I can download large files from the internet to an internal computer via
a masq'ed connection thru the server, but I get very very few collisions
that way.

P.S. Is it normal not to get a full 10Mbps out of 10Mbps hardware?