topic Re: Issue with tcpdump in Operating System - Linux

Issue with tcpdump

girishb — Wed, 13 Sep 2006 17:13:42 GMT

Hi All,

Having problem with tcpdump command on RHEL. We are experiencing "Couldn't find user 'pcap'"

Example:
[root@server root]# tcpdump -i eth0 icmp
Couldn't find user 'pcap'

I need to solve this urgently.

Thanks in advance for the response.

Girish

Re: Issue with tcpdump

Stuart Browne — Wed, 13 Sep 2006 18:04:37 GMT

http://lists.planet-lab.org/pipermail/users/2005-July/001562.html

Long answer:

The install routine that adds the 'pcap' user sometimes doesn't do it properly. This has been reported to various buglists etc. but as yet doesn't appear to have been fully resolved.

Short answer/fix:

Manually add the user. Decent command line is in that URL.

Re: Issue with tcpdump

Ivan Ferreira — Wed, 13 Sep 2006 18:06:34 GMT

Try just adding the pcap user:

adduser pcap

May be required to run tcpdump.

Re: Issue with tcpdump

girishb — Thu, 14 Sep 2006 15:12:46 GMT

Thanks folks.

useradd pcap has worked.

Re: Issue with tcpdump

girishb — Thu, 14 Sep 2006 15:14:27 GMT

Thanks folks