DHCPStatus


What is DHCPStatus ?
====================
DHCPStatus is a query tool for browsing information stored in DHCPD's 
configuration and leases files, dhcpd.conf and dhcpd.leases. It correlates the 
subnet details that you configure in the conf file with the lease records that 
DHCPD maintains in its lease file. You can thus obtain an overall picture of 
your DHCP environment, as well as view details of individual leases for each 
IP.

DHCPD, by the way, is a DHCP server daemon, produced by the Internet Software 
Consortium. 

DHCPStatus can be run either as a CGI script and viewed via a web browser, or 
as a command-line tool that generates simple text output.  The CGI/web 
interface requires that you run a CGI-capable web server on your DHCPD server 
machine.  The command-line tool merely requires that you have a shell login on 
the server.


What information does DHCPStatus give you ?
===========================================
DHCPStatus provides information about your DHCPD environment at two levels: an 
overall summary report, and a subnet detail report.

Summary report.
---------------
Each row of the summary report contains information for a single subnet 
defined in the dhcpd.conf file.  The information described for each subnet is:
   - the subnet address
   - netmask
   - the range of IP addresses that fall within the subnet
   - the router(s) for the subnet
   - the number of IP addresses that are defined in the dynamic pool for that  
     subnet
   - the number of IP addresses in the dynamic pool that are in use
   - and the number of IP addresses in the dynamic pool that are free

All this information is obtained from the dhcpd.conf and dhcpd.leases files, 
in their standard formats. In addition, if you use an extra format standard 
for commenting each subnet in your dhcpd.conf file, this utility will find 
those comments and include them as a "Location" field in the summary report.

Subnet detail report.
---------------------
For each subnet that is summarised by the summary report, it is possible to 
obtained a detailed subnet report.

The information displayed in the subnet detail report includes all of the 
information that is produced by the summary report for that subnet, as well as 
a row of information on each IP address in the subnet. The information for 
each IP address includes the lease status ("active", "free", or blank for IP 
addresses not in the dynamic pool).

For each active IP address, the following is displayed:
   - the start date of the lease
   - the end date of the lease
   - the mac address of the interface that has the IP address lease
   - the DNS name of the interface that has the lease (as supplied by the      
     client)
   - and the hostname (or WINS name, assuming the client is using WINS) of the 
     machine that has the lease.

Overall, these two reports provide a quick and easy way of summarising the 
status of your DHCPD server (a lot easier than scanning through the 
dhcpd.leases file manually :-)


Requirements.
=============
If you want to use DHCPStatus, you'll firstly need read access to your 
dhcpd.conf and dhcpd.leases files.  You'll also require Perl 5.003 (or later) 
installed on your system.

If you choose to run the CGI/web interface with DHCPStatus, then you'll need 
to run a web server on your DHCPD server.  The userid that the web server runs 
as will need read access to your dhcpd.conf and dhcpd.leases files.  
Alternatively, if you want to use the web interface but don't want to install 
a web server on your DHCPD server, then you could run the CGI script from 
another machine that had access to the dhcpd.conf and dhcpd.leases files via, 
say, an NFS mount.

There are no pre-requisites for the command-line interface to DHCPStatus 
(other than, obviously, Perl and read access to your DHCPD files).  The 
command-line version assumes that your terminal display width is 80 characters 
(you can easily change this width value in a .ini file).  However, if you have 
the Perl Term::ReadKey package installed on your system, DHCPStatus will use 
it to determine your screen width (see 
http://search.cpan.org/search?dist=TermReadKey).


Installation.
=============
See the INSTALL file.


License.
========
DHCPStatus is freely available under the terms of the GNU General Public 
License.  However, if you find this product useful and wish to offer 
appreciation for it, then please make a contribution to your local animal 
welfare society.


The Author.
===========
DHCPStatus was written by Michael Grubits.  Please send all 
criticism/praise/patches/change requests/offers of telecommuting 
employment/etc. to mjtg@users.sourceforge.net.