On Sun, Dec 04, 2011 at 01:01:07PM -0000, Matthew Green wrote:
Does the switch offer you a counter of bad ethernet frames?
You can get the info for the PC end from ethtool: mephi@mephi-server:~$ sudo ethtool -S eth0 NIC statistics: tx_packets: 0 rx_packets: 0 tx_errors: 0 rx_errors: 0 rx_missed: 0 align_errors: 0 tx_single_collisions: 0 tx_multi_collisions: 0 unicast: 0 broadcast: 0 multicast: 0 tx_aborted: 0 tx_underrun: 0
specifically you're looking for rx_errors, the other end (the switch) will need to report on it's rx_errors
If your switch can't do that you can always connect two PCs back to back with the cable.
To test, you'll need to spam a whole load of data over the cable using something like iPerf and then check those counters. BTW, There's no way (that I know of) to reset those counters (on linux, a lot of switches can) except by restarting the PC.
Thanks, that sounds like the sort of thing I'm after. Presumably as long as I see no tx_errors:, rx_errors: or rx_missed: then there's nothing seriously broken anywhere.
The cable I'm most interested in from this point of view is one that run's to the backup system in the garage so I can look at the statistics over a few days of backups to see if there's anything wrong. Both my desktop system and the garage backup system are alway on so the counters won't get cleared.