Collisions on local net

[Radar]

What could cause collisions on a small LAN?

eth0 Link encap:Ethernet HWaddr 00:08:C7:E9:FC:52
inet addr:192.168.0.2 Bcast:192.168.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:651305 errors:0 dropped:0 overruns:0 frame:0
TX packets:548934 errors:0 dropped:0 overruns:0 carrier:0
collisions:23545 txqueuelen:100
RX bytes:677269303 (645.8 MiB) TX bytes:49020975 (46.7 MiB)
Interrupt:11

Machine A: EEpro 100
Machine B: 2-3com 590B
Machine C: 1-3com 590B
Hub: 4 port netgear 10Mbps

TIA

[jscott]

http://www.cisco.com/warp/public/63/eth_collisions.html
http://commeng.cso.uiuc.edu/~monnin/ethernet/ethernet.html
http://www.ethermanage.com/ethernet/enet-misc/collision/collision.html

for more info on collisions.

basically, isht happens... You're using a 4 port [which is full if I read your post correctly] hub. A hub is a shared connection, meaning only one computer can talk at a time. My mp3 server's uptime reports only 8 days, but the collision count is 1814151. Ethernet was designed to take these problems into account. Unless it's affecting your network seriously, it's not much to worry aboot.

[cowanrl]

Originally posted by Radar:
<STRONG>What could cause collisions on a small LAN?

TIA</STRONG>

Collisions are a normal part of most Ethernet LANS. The only time you won't experience collisions is if you are running full duplex or every machine has it's own port on a switch.
In your case, lets assume your machine is only counting the collisions it detects when it tries to transmit. You transmitted 548934 packets and only experienced 23545 collisions. That's less than 5%. Not out of the ordinary at all. If your machine is counting all collisions that occur on the network, then the percentage is even less.
Since you're not experiencing any errors, I'd say your network is healthy.

The number of collisions that occur on a network depends upon the type of traffic. If all three of those machines were transferring large files at the same time or were all accessing the Internet simultaneously, lot's of collisions could occur.

[Radar]

Thanks to both - very helpful. I feel better now.