DHCP/BOOTP Server

A simple DHCP/BOOTP server can be started to support target-based network bootup. This server is single threaded (meaning that it can only deal with one DHCP transaction at a time). It is not intended for use on a loaded network, rather to provide basic support for single device network bootup. The menu item Servers->DHCP brings up the following dialog box:

This facility provides a very basic DHCP/BOOTP server for targets that have been configured to network boot. It supports 'automatic allocation' mode (see RFC2131) in which the server simply assigns an IP address that is then assumed to be owned by that client. The server can be configued in two different ways, single-client mode or file mode. Note that in either mode, the transaction can be monitored if DHCP system trace is enabled (see Config->SystemTrace) and the trace window is visible.

CONFIGURATION Single-Client Mode:

A simple, single-client server can be established by activating the "Single-Client Config" radio button and filling in the appropriate items within the group. The server is then enabled by checking the "Enable Server" box and clicking OK. At that point the server will then wait for a DHCP or BOOTP request from a client that has the specified MAC address, and assign the other specified items to that client upon request. The syntax of each entry is typical; except for the ServerIP... For this entry, the IP address can be immediately followed by a comma ',', in which case the string after the comma will be used as the server name when the DHCP server replies to a request.

CONFIGURATION File Mode:

In this mode, the server requires a configuration file be established. To enter this mode, activate the "File-Based Config" radio button. This will enable that group in the dialog box. A template config file is created when a new config file is built by clicking on the "New" button. When starting up, the server reads in the config file and converts that data to binary for quick parsing when incoming DHCP requests are received. The purpose of the config file is to allow the server to uniquely configure multiple clients based on the client_macaddr field of the incoming DHCP_DISCOVER request.

When the server is running and a client makes a DHCP request, the server can print out the state transitions occurring as the transaction progresses. This trace must be enabled through the System Trace dialog box..

Note that for both Single-Client and File Configuration modes, the parameters can be specified as shell variables. For example, in the case of Single-Client Configuration, this just means that you can put $CLIENT_IP_ADDR in the "Client IP:" text box instead of a hard-coded IP address. Obviously this means that the shell variable must exist when the server is started, so if it doesn' t an error will result.

EXAMPLE CONFIG FILE:

uCon can generate a configuration file that can be used as a template.

Following is an example of that output...