DHCP Server: Flexible IP address ranges, GUI improvements

Welcome update in Alax.Info DHCP Server to provide flexibility in IP address allocation ranges and more features.

The application does not require that IP address block is a single range of addresses. While this is still cool for simplicity, some guys out there have really huge networks with specific requirements. From now on, an “advanced” links opens an additional opportunity to:

  • define multiple blocks of IP addresses to get from
  • opportunity to provide exclusion addresses, ranges and even wildcards

The syntax is straightforward:

  • one range per line, x.x.x.x-y.y.y.y
  • optional exclusion list following in brackets
    • excluded items are separated by comma
    • excluded item may be a single address x.x.x.x, range x.x.x.x-y.y.y.y or a wildcarded address/range x.x.*.x-y.y.*.y

Additionally, it is possible to include DNS Domain Name (option 15) with the DHCP responses:

The GUI makes it clear that it is possible to provide multiple addresses using comma separation. While this was possible before UI did not make it clear enough.

More to this,it is possible to export lease list into clipboard in comma-separated value (CSV) format and transfer data into, e.g. Microsoft Excel:

Updated Alax.Info DHCP Server is cooler and fancier at the same unbelievable price: free for personal use, commercial license for premium features, non-personal use and technical support.

DHCP Server: List of Issued Leases

Alax.Info DHCP Server was updated to provide user interface and show a list of issued DHCP leases, including:

  • hardware (MAC) address and IP address correspondence
  • latest date and time of DHCP lease issue
  • sortable list to be able to conveniently arrange entries and lookup items of interest

DHCP Lease List

Other changes include:

  • stores latest lease issue date and time in registry to be able to locate recently issued leases
  • indicates Windows service status through system tray icon (running or stopped)
  • minor fixes

Release information:

DHCP Server: More Configuration Choices for Router, Time Server and DNS Server (Options 3, 4 and 6)

Alax.Info DHCP Server received more configuration options and allows customizable DHCP parameters, options 3, 4 and 6:

Tag       Name                             Length  Meaning                                           Reference
--------  -------------------------------  ------  ------------------------------------------------  ---------
3         Router                           N       N/4 Router addresses                              [RFC2132]
4         Time Server                      N       N/4 Timeserver addresses                          [RFC2132]
6         Domain Server                    N       N/4 DNS Server addresses                          [RFC2132]

Application GUI allows configuration of the options, including multiple IP addresses per option and “this” placeholder to be replaced with selected network adapter’s IP address:

Options Property Page

The DHCP Server application responds to the network device with a packet of the following kind (captured by WireShark):

Wireshark DHCP ACK Packet

Release information:

DHCP Server: VoIP Configuration Server Address Options 66 and 150

Alax.Info DHCP Server was updated and received a new feature to send TFTP Server Name (DHCP option 66) and TFTP Server IP Addresses (DHCP option 150) so much required to automatically configure VoIP hardware.

DHCP Server TFTP Server Options

Option 150 is defined by internet draft “VoIP Configuration Server Address Option”:

   This memo documents existing usage for the "VoIP Configuration Server
   Address Option" (previously known as the "TFTP Server IP Address
   Option").  The option number currently in use is 150.  This memo
   documents the current usage of the option in agreement with RFC 3942
   [RFC3942], which declares that any pre-existing usages of option
   numbers in the range 128 - 223 should be documented and the working
   group will try to officially assign those numbers to those options.

Release information:

DHCP Server: Running out of available trial/demo leases

I have been recently asked a question (by the way through new Jabber/XMPP/GoogleTalk based web chat) about DHCP Server leases.

I’m using the trial version of Alax.Info DHCP Server
And it says there are no more IP addresses available… Do I have to register?

Registration definitely would not hurt, however there is also an alternative. Issued leases are kept in registry under HKEY_LOCAL_MACHINE\SOFTWARE\Alax.Info\DhcpServer\Leases key. It is possible to open registry editor and remove some of the leases or even delete all of them (or rename key to be able to restore) in order to reset current DHCP Server state and allow it issue new leases again. This trick resets lease counter and allows having new five IP addresses given out by server to old or new MAC addresses.