Re: Collisions on lan using Linux versus Windows

["Tony Wasson" <ajwasson@inficad.com>]

> My network performance is pretty good, I believe. However when I
> transfer files between two of my systems both running Debian the
> collision led on my hub is almost constantly on.
>
> I transferred a 82 MB file. I ran ifconfig before and after:
> collisions:560494 txqueuelen:100
> collisions:590036 txqueuelen:100

Collisions have almost no practical value in troubleshooting network
performance problems. Anything they do tell you can be seen sooner and more
clearly from some other statistics. A 'lit' collision light is normal when
doing a large file transfer. I have observed 100% collisions during some FTP
transfers and gotten very good throughput. Normal collisions are a feature
of CSMA/CD, not a problem. Your network throughput 65%, which is excellent
considering that you are using encryption.

Out of the 'ifconfig -a' out put I'd be most concerned about drops, then
about large amounts of frame errors, and finally about general 'errors'.

Here's the formula to calulate throughput:

                        bytes
Throughput =   -----
                   time * network speed in bytes

You said 82 MB, but I'm assuming you mean 82,000,000 (not 85,983,232 bytes)
time is in seconds (1:41 is 101 seconds)
10mbps throughput = 1,250,000 bytes