Posted on September 19, 2016 1:08 pm
 |  Asked by Toshio Taga
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Hi all,

I have 3 questions.

1. When I use bash command “ifconfig” from Arista SW. It showing “CPU” , why ifconfig show CPU ?
When I use ifconfig command on Linux server, it doesn’t show CPU.
Why “CPU” showing bash command “ifconfig” ?

2. Why different MAC address show , Cli and bash ?
3. Bash ifconfig show same MAC address for all interface , why ?

Thank you,Toshi.

Answered on September 19, 2016 3:36 pm

Hi Toshi,

To answer your questions in order;

  1. CPU is present, as an interface, in the ’ifconfig’ command output as there is a CPU network interface representation in the kernel to handle software-forwarded traffic e.g. packets with TTL expired, etc.
  2. The ’ifconfig’ utility is showing the kernel representation of the front-panel interfaces, rather then the hardware as shown through the CLI
  3. If you compare to the output of ’show version’ you will see that the MAC address shown for the kernel representation of each front-panel port is the System MAC Address.


Posted by Toshio Taga
Answered on September 21, 2016 2:31 am

Thanks Colin.

I understand them.

Thank you,

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