I have a system (x86_64) running Debian Lenny on a standard Gigabit Ethernet 
LAN. I have been doing some researching on how to measure Ethernet CRC errors 
(Physical layer), if there are any, on my Debian system's ethernet card . It is 
clear that the ethereal (now wireshark) cannot measure it [1]. Some people have 
suggested to use the following commands to get the CRC count:

# cat /proc/net/dev
Inter-|   Receive                                                |  Transmit
 face |bytes    packets errs drop fifo frame compressed multicast|bytes    
packets errs drop fifo colls carrier compressed
    lo: 1230934    5159    0    0    0     0          0         0  1230934    
5159    0    0    0     0       0          0
  eth0:14527038631 174773921    0    0    0     0          0         0 
53768205408 150237839    0    0    0     0       0          0


#ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:1f:d0:35:74:b5  
          inet addr:  Bcast:  Mask:
          inet6 addr: fe80::21f:d0ff:fe35:74b5/64 Scope:Link
          RX packets:174700827 errors:0 dropped:0 overruns:0 frame:0
          TX packets:150164953 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:14522357501 (13.5 GiB)  TX bytes:53726785504 (50.0 GiB)
          Interrupt:254 Base address:0xe000 

As per [2], they say that "Copper cabling should not experience more than one 
bit error per 10^6 bits." But as you can see even after tx and rx data in GBs, 
I still don't have any CRC errors??? May be it might be the case that there are 
actually no CRC errors so far but it is hard for me to believe. So my two 
questions are:

a) Does the above two command really give you the hardware CRC count? Or does 
the Linux driver/OS masks it somehow?

b) Does anyone know any other method in Linux to measure the Ethernet CRC 

I am wondering how much CRC errors people on this list are getting using the 
above two commands.

Any light on this subject is highly appreciated.

# ethtool -i eth0
driver: forcedeth
version: 0.61
bus-info: 0000:00:07.0

[1] http://www.fpgarelated.com/usenet/fpga/show/31620-1.php

[2] http://www.mail-archive.com/ci...@groupstudy.com/msg93750.html

Kushal Koolwal

I do blog at http://blogs.koolwal.net/                                    
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