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Configuring the DHCP Server for the Solaris OS or OpenSolaris OS

Jeppe Toustrup, June 2009

When people are going to set up a DHCP server on a UNIX or Linux system, chances are that they will use the ISC DHCP server, since it is included in many distributions. However, it is not included with the Solaris Operating System or the OpenSolaris OS. So, in this case, people might include their own DHCP server, which is a lot different to configure.

This tech tip provides a procedure to get you started configuring a DHCP server by using the bundled DHCP server provided in the Solaris OS or the SUNWdhcs package for the OpenSolaris OS. I will configure the DHCP server with some static entries for specific hosts, and also with a small pool of addresses for random users.

Note: This procedure works with both the Solaris 10 OS and the OpenSolaris OS. It has not been tested on Solaris versions other than version 10.

The DHCP server is found in the Solaris OS as the SUNWdhcsr and SUNWdhcsu packages.

However, you have to install the package named SUNWdhcs in the OpenSolaris OS. This is done by running the following command:

$ pfexec pkg install SUNWdhcs

After the installation, you should start off by using the dhcpconfig command to set up the initial configuration directory to hold the settings used by the DHCP server:

$ pfexec dhcpconfig -D -r SUNWfiles -p /var/dhcp -a 192.168.0.1 \
-d office.lan -h files -l 86400

The parameters are as follows:

• -D: Specifies that we are setting up a new instance of the DHCP service.
• -r SUNWfiles: Indicates that we want a plain-text file store. Other options are SUNWbinfiles and SUNWnisplus, but I won't be covering those here.
• -p /var/dhcp: Provides an absolute path to where the configuration files should be stored.
• -a 192.168.0.1: Specifies the DNS server to use on the LAN. You can specify several by separating them with commas.
• -d office.lan: Specifies the domain name to use for the network.
• -h files: Specifies where the host information should be stored. Other values are nisplus and dns.
• -l 86400: Specifies the lease time in seconds. 86400 seconds = 24 hours.

After that, you need to create the network we are going to set up. This is done with the following command:

$ pfexec dhcpconfig -N 192.168.0.0 -m 255.255.255.0 -t 192.168.0.1

The parameters are as follows:

• -N 192.168.0.0: Creates a new network with the specified network address
• -m 255.255.255.0: Specifies the network mask to use for the network
• -t 192.168.0.1: Specifies the default gateway

All the previously entered network settings are put into macros, each of which is a small assembly of configuration options. Macros make it easier to put a group of settings on specific hosts. You can see which macros are currently created and their settings by running the following command:

$ dhtadm -P

You will see that three macros are created. One macro is named after your server's host name, and it contains the settings specified as system-wide settings with the first dhcpconfig command.

Another macro has the name of the network you just created, and it contains the settings entered in the last command.

The last macro named Locale simply holds timezone information, with a setting claiming the amount of seconds your local timezone differs from UTC.

As you can see from the output, the current time server is set to 127.0.0.1, which isn't going to do any good for the DHCP clients. So we are going to correct that to 192.168.0.1, the same address used by our default gateway and DNS server. The change is done like this:

$ pfexec dhtadm -M -m `hostname` -e Timeserv=192.168.0.1

The parameters are as follows:

• -M: Specifies that we are going to modify a macro.
• -m `hostname`: Specifies the macro we are going to modify. The shell replaces `hostname` with your server's host name.
• -e Timeserv=192.168.0.1: Specifies the setting we want to change, and what it should be changed to.

Again, you can check that the setting is indeed changed with this command:

$ dhtadm -P

We are also going to alter the 192.168.0.0 macro, and set it to include the settings from the `hostname` macro:

$ pfexec -M -m 192.168.0.0 -e Include=`hostname`

The last command used to configure the DHCP server is pntadm, which sets up settings for each host on the network. The following command adds a static DHCP entry for a host:

$ pfexec pntadm -A 192.168.0.2 -c "Comment" -f MANUAL \
-i 01001BFC92BC10 -m 192.168.0.0 -y 192.168.0.0

The parameters are as follows:

• -A 192.168.0.2: Adds the IP address 192.168.0.2.
• -c "Comment": Specifies a comment for the entry, for your own convenience.
• -f MANUAL: Sets the flag MANUAL in order to only assign this IP address to the MAC address specified.
• -i 01001BFC92BC10: Sets the MAC address (Client_ID) for the host this entry goes to. Should be prepended with 01 to specify that this is an Ethernet address.
• -m 192.168.0.0: Specifies that this host is going to use the 192.168.0.0 macro.
• -y: Verifies that the macro entered actually exists.
• 192.168.0.0: Specifies the network the address is assigned to.

The command to check the settings is:

$ pntadm -P 192.168.0.0

And now we add an IP address for any host on the network:

$ pfexec pntadm -A 192.168.0.10 -m 192.168.0.0 -y 192.168.0.0

The same parameters apply as before, but we have just left out a lot more options, since we don't know which host is going to get this address.

The last thing to do is to restart the DHCP server, in order for all the changes to take effect:

$ pfexec svcadm restart dhcp-server

And then you are done.

References

• System Administration Guide: IP Services
• Man pages in the Solaris 10 Reference Manual Collection

About the Author

Jeppe Toustrup has been playing around with Linux, the Solaris OS, and various other pieces of open source software for the last ten years, and has been working professionally as a system administrator at Danish ISPs for the last five years.

Unless otherwise licensed, code in all technical manuals herein (including articles, FAQs, samples) is provided under this License.