[NTLUG:Discuss] DHCP diagnostic program

[Preston Hagar]

On Thu, May 5, 2011 at 11:41 PM, Leroy Tennison
<leroy_tennison at prodigy.net> wrote:
> I'm looking for a program to test DHCP server responses.  Specifically, I
> need a program where I can specify the DHCP server and options I want
> returned (option 176 specifically since this is telephony-related) and have
> it display the results (preferably without assigning anything to the host).
>  Any ideas?  Thanks for your help.
>

This may be too basic for what you are looking for, but the check_dhcp
script in Nagios can do most of what you want.   In ubuntu, you would
do

apt-get install nagios-plugins

then, go to /usr/lib/nagios/plugins

>From there, you could run something like

./check_dhcp -v -i eth2 -s 10.1.254.253

which would specify verbose, use eth2, and use 10.1.254.253 for the
DHCP server.  You can also specify the MAC address you want to send if
you want to.   Running the command above against my DCHP server
returns:

http://pastebin.com/4mwcnVDr

Not sure if that helps or not.  If I run it with a -m and put in the
MAC address of a phone, then I get the extra 66, 67, 128, 129, 130
options our phones get (we have a Mitel VoIP system).  It doesn't seem
to show the values being sent though for the phones, so I am not sure
how much help it might be.

Also, we use the ISC dhcp server and use it for our Mitel 5212, 5224,
and 5500 phones.  If it would be of any help to you, I would be glad
to share the config file.

Preston