Interface collisions

Jack L. Stone jackstone at
Mon Mar 31 08:34:13 PST 2003

At 09:57 AM 3.31.2003 -0600, David Kelly wrote:
>On Mon, Mar 31, 2003 at 08:38:04AM -0600, Josh Paetzel wrote:
>> On Mon, Mar 31, 2003 at 08:20:34AM -0600, Jack L. Stone wrote:
>> > For the first time within the past few days, I've noticed collisions
>> > reported on the public NIC for one of the servers. I'm not sure if it
>> > the switch or the NIC is the culprit, so not sure which component may
>> > to be replaced.
>> > 
>> > Name  Mtu   Network       Address            Ipkts Ierrs    Opkts
Oerrs  Coll
>> > rl1   1500  <Link#2>    00:40:33:5b:bb:5f  6816063     0  7494432     0
>> > 66977
>> I'm lazy, I would replace the cable first.  If that didn't work I'd
>> the $10 realtech card, and if that didn't work then I'd suspect a bad
port on 
>> the switch.
>You would sweat over a number which says less than 1 in 100 packets sent
>had to back off and requeue? No matter that "other machines with same
>hardware/software don't accumulate collisions" I don't believe this
>connection is broken.
>Others have suggested hard setting the data rate and duplex on the NIC.
>That is not a bad idea, especially when using less than premium
>Replacing the cable isn't a bad idea either. Often when a UTP cable is
>wired incorrectly by not observing proper pairing of wires (honor the
>Twisted Pair part of UTP) it mostly works but crosstalk between wire
>pairs is more than it should. Enough to cause errors. I've seen machines
>run for months wrongly wired until the position of the sun and moon are
>finally unfavorable enough that the system falls off the net.
>The sad thing is that 3Com NIC's tend to work thru the bad wire while
>everything else I have fails immediately. That's both good and bad.
>Would like to turn off the 3Com's added ability for initial installation
>then turn it on for production as extra margin for dependability. But
>now that I know, I bring my laptop for debugging the connection.
>David Kelly N4HHE, dkelly at

I truly appreciate everyone's suggestions about this and the concensus
appears to be that I will need to change the NIC from "autoselect" to a
hard setting of "full duplex". The card is indeed inexpensive, not premium
and after more than a year of use perhaps has begun to fail.

Also, I agree that the collisions are very small and were cached by the
switch, not lost necessarily. However, the sudden appearance over the past
2-3 days indicates a change that is not for the better and more concerned
about the trend.

Thanks again fellows....

Best regards,
Jack L. Stone,

SageOne Net
jackstone at

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