JDHCPSim

[Gene Rackow]

This looks like a very interesting tool. 

Our networking group is looking for a tool that can be used to just test the availablity
of the dhcp server.  We've run into some very strange problems where randomly something happens
that prevents the response from getting back to the clients on specific subnets.  We hven't been
able to determine the exact cause yet.  Almost anything appears to reset the condition.
A  reset on the dhcp server port, a ifdown/up of the dhcp server interface, a reset of the 
interface for one, not all, of the wireless access points on that subnet, etc.  Very odd.
We've  tried running network dumps along the way, but so far things really don't make much
sense.  We need to start catching this problem before the users start seeing it.

Before attempting to use this to create such a tool, does anyone
already have something liek a nagios or bigbrother module that could be used?
I think it would be pretty easy to do with this.  Just wondering if it's already been done.

Or possibly a tool that
  sends a dhcp request
  if no-response or bad-response, send mail to sysadmin

--Gene
  
Ragnar Lonn made the following keystrokes:
 >For outgoing packets, you cannot currently specify source- or destination
 >port. It sends from port 68 to port 67, like most clients will do. But being
 >able to change source- and destination UDP ports is a useful feature and
 >something we will probably add for the next version.
 >
 >For incoming packets it reads raw ethernet frames from the interface
 >specified, and will report any packets it sees that contains the DHCP
 >magic cookie. So the packets don't have to arrive on or from any
 >particular UDP port.
 >
 >Regards,
 >
 >  /Ragnar
 >
 >
 >Frank Bulk skrev:
 >> Neat....does that tool allow one to simulate a relay agent?
 >>
 >> Can one specify ports, too?  We had an issue with a DHCP appliance that
 >> would not respond correctly to relayed src 67/dst 67 packets, but it would
 >> on 68/68 packets.
 >>
 >> Regards,
 >>
 >> Frank
 >>
 >> -----Original Message-----
 >> From: dhcp-users-bounce at isc.org [mailto:dhcp-users-bounce at isc.org] On Behalf
 >> Of Ragnar Lonn
 >> Sent: Monday, January 08, 2007 4:30 AM
 >> To: dhcp-users at isc.org
 >> Subject: Re: JDHCPSim
 >>
 >> If you need something that can emulate different types of DHCP client
 >> behaviour, we have a tool called DHCPTool that is free to download here:
 >>
 >> http://gatorhole.com/index.php?product=dhcp&lang=gb
 >>
 >> Regards,
 >>
 >>   /Ragnar
 >>
 >>
 >> Heiko Großstück skrev:
 >>   
 >>> Does anyone have the tool JDHCPSim (in version 1.1)?
 >>> I need this to test a DHCP server, but the site of the developer is down:
 >>> www.descension.org/~boggan/JDHCPSim.html
 >>> (internet archive doesn't have the *.gz)
 >>>
 >>> thanks
 >>> Heiko
 >>>   
 >>>     
 >>
 >>
 >>
 >>   
 >
 >