Posted on November 12, 2019 10:26 pm
 |  Asked by Mike Cotrone
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I am using EOS version 4.20.11M and it appears that bash commands are not responding to the & (background process). Originally my software launches iperf from the EOS cli “bash timeout 10 iperf (flags) &” which worked in older versions of EOS. Now from the CLI I launch any command ie “bash iperf -s &” or “bash tcpdump &” and then I go to bash to do a “ps -aef” neither of my called apps are processing in the background. (Both examples above I also used “bash timeout 10”.

Is this intended and thank you in advance.


Answered on November 12, 2019 11:13 pm

Hi Mike,

Thank you for writing to the forum.

Quick recreate in the lab shows that the command does run in the background. Please see the lab snippet below:

Arista DCS-7260CX3-64-F
Hardware version: 11.03
Serial number: <>
System MAC address: <>

Software image version: 4.20.11M

[admin@gd502 ~]$ tcpdump -nei et17_1 &
[1] 17806

[admin@gd502 ~]$ ps -aef | grep tcpdump
admin 17806 17742 0 23:02 pts/6 00:00:00 tcpdump -nei et17_1 <<<< admin 17823 17742 0 23:02 pts/6 00:00:00 grep --color=auto tcpdump Also, the packets captured showed up on the CLI in bash. If the issue persists for you, I request that you contact Arista TAC by sending an email to or dialing their numbers for assistance. Thank you,

Posted by Mike Cotrone
Answered on November 13, 2019 3:26 am

Thanks for verifying Dharmesh - I will try to recreate later, but as of now its working fine (I saw this on my 7280SR2 and 7124 earlier - I must have had something else going on locally. Weird and I'm happy as I don't have to troubleshoot my code :)

Thanks and have a great day.
- Mike

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