1-2-3 DHCP

            Today I just wanted to document here the quickest and easiest way of setting your Solaris box as a DHCP client. Setting up a Sun Solaris Server to receive its IP address from a DHCP Server is fairly straight forward and is infact just a matter of setting up files on your Solaris Server.

dhcpagent is the dhcp client thats running on your Solaris operating system. With this in place create the following file:

1. Create the /etc/hostname. <interface>

This will be an empty file

sun1# touch /etc/hostname.e1000g0

                                                                  

Repeat the above for all the avaliable interface cards on which you would like to have the IP from DHCP.

2. Create the /etc/dhcp.<interface>

This is also an empty file

sun1# touch /etc/dhcp.e1000g0  

                                                           

but you can also use it to specify how long ifconfig should be waiting for a DHCP-server reply before giving up and continuing with Solaris boot.

sun1# cat /etc/dhcp.e1000g0    

wait 60 ( default 30 sec)            ------> (Can be any value or forever)

primary                                                ------> (To notfy ifconfig about primary interface incase you have more tha one interface)

3. Specify your system name

It has to be specified in /etc/nodename. This name is going to be used as your hostname in case your DHCP-server does not return your hostname in reply to your DHCP-request.

                       

sun1# cat > /etc/nodename 

sun2                         

Reboot your system, and it all should work !!!

As simple as that, 1-2-3 DHCP

Appendix A:

Problem: Unknown hostname

            Actually, there's one snag: most (if not all) cable modem DHCP servers don't provide you with a hostname (even if they did, odds are it won't be one you want anyway!). This wouldn't be a problem, except that the boot scripts (/etc/init.d/rootusr in particular) try to be clever, and set your hostname to "unknown" in this case, which is not at all useful!

Solution: Add the hostname to /etc/nodename as mentioned earlier.

Appendix B: Tunable dhcpagent parameters.

Below is the file which needs to be modifed to have changes according to requirments.

                                                           

            /etc/default/dhcpagent

                                                             

Most important parameter value attribute is below.

PARAM_REQUEST_LIST=1,3,6,12,15,28,43

This variable tells dhcpagent what to request for from DHCP server.

Each value in the above list has specific meaning.

    1 = subnet mask

    3 = Default Router

    6 = DNS Server

    12 = hostname

    15 = DNS Domain Name

    28 = broadcast address

    43 = Encapsulated Vendor options

If you doesn't want the client to request for hostname delete number 12 followed by its comma (,) symbol