Wireshark

AXISHK
AXISHK used Ask the Experts™
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Is it possible to use Wireshark to find out a DHCP server in a VLAN ?
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Qlemo"Batchelor", Developer and EE Topic Advisor
Top Expert 2015

Commented:
Yes, of course. You just need to filter for all BOOTP/DHCP stuff, and then send a DHCP request (or wait for any to be send).
But DHCP servers do not advertise themselves without a request. Info needs to get "pulled".

Author

Commented:
Sure, I will plug a computer into this VLAN and monitor it through wireshark.

I'm not familiar with wireshark. Can you assist me with screen dump how to setup it up ?

Tks
"Batchelor", Developer and EE Topic Advisor
Top Expert 2015
Commented:
After starting WireShark, press "Capture Options", check that the correct NIC is selected, and set this as Capture Filter:
  port 67 or port 68
Also "Use promiscuous mode" should be set.
That should be all.

Author

Commented:
Tks
You might find this blog and video useful - http://www.lovemytool.com/blog/2015/10/introduction-to-packet-analysis-dhcp-by-paul-offord.html

It covers exactly what you are looking for.

Best regards...Paul

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