ISC DHCP for AI

This section describes how to configure ISC DHCP to serve the information you need for AI installations.

Basic Network Configuration

Define a basic network in your dhcpd.conf file. In the following example, the 192.168.0.0/24 network is defined to serve out IP addresses between 2-100 with a router of 192.168.0.1:

subnet 192.168.0.0 netmask 255.255.255.0 {
  range 192.168.0.2 192.168.0.100;
  option routers 192.168.0.1;
}

DNS Configuration

Similarly, add DNS information to your dhcpd.conf file. If you want each subnet served to get different DNS information, either put the directives in the subnet block or put the directives at the beginning of the file to affect all subnets served.

option domain-name "example.com";
option domain-name-servers 192.168.0.1;

Boot Server and Boot File Configuration

AI requires boot server and boot file configuration in DHCP. When you boot a client machine for automated installation, that client needs to know where to get a boot file (from the AI server) and the name of the boot file. These pieces of information are provided by the installadm create-service command when you set up an AI service. The following example shows partial output from an installadm create-service command:

Boot server IP (BootSrvA) : 192.168.0.1
Boot file      (BootFile) : install_test_ai_x86
GRUB Menu      (GrubMenu) : menu.lst.install_test_ai_x86

In ISC DHCP terms, the boot server is the next-server directive and the boot file is the filename directive. Add these directives to your subnet group, as shown in this example:

subnet 192.168.0.0 netmask 255.255.255.0 {
  range 192.168.0.2 192.168.0.100;
  option routers 192.168.0.1;
  filename "install_test_ai_x86";
  next-server 192.168.0.1;
}

For a SPARC AI service, use the same filename directive for the BootFile object. SPARC installations do not need a next-server (BootSvrA) directive.

If you are using AI to install both SPARC and x86 machines, use the ISC DHCP class directive to provide boot file information to the SPARC clients and provide boot file and boot server information to the x86 clients. Providing boot-specific information in separate class directives enables you to have a default service for each architecture on the network.

PXE Boot Class

The following example is a class definition for an x86 hardware boot:

class "PXEBoot" {
  option dhcp-class-identifier "PXEClient";
  filename "install_test_ai_x86";
  next-server 192.168.0.1;
}

SPARC Boot Class

The following example is a class definition for SPARC hardware boot. Note that you do not need a next-server directive for SPARC:

class "SPARC" {
  match if ( substring (option vendor-class-identifier, 0, 5) = "SUNW." ) and not
           ( option vendor-class-identifier = "SUNW.i86pc" );
  filename "http://192.168.0.1:5555/cgi-bin/wanboot-cgi";
}

Sample Configuration File

With these class definitions, SPARC clients request a lease and get SPARC specific information, and x86 clients request and get information specific to x86. The following examples shows the entire dhcpd.conf file:

# option definitions common to all supported networks...
option domain-name "example.com";
option domain-name-servers 192.168.0.1;

default-lease-time 600;
max-lease-time 86400;

# If this DHCP server is the official DHCP server for the local
# network, the authoritative directive should be uncommented.
authoritative;

# Use this to send dhcp log messages to a different log file (you also
# have to hack syslog.conf to complete the redirection).
log-facility local7;

# This is an easy way to discriminate on SPARC clients
class "SPARC" {
  match if ( substring (option vendor-class-identifier, 0, 5) = "SUNW." ) and not
           ( option vendor-class-identifier = "SUNW.i86pc" );
  filename "http://192.168.0.1:5555/cgi-bin/wanboot-cgi";
}

# This is a class to discriminate on PXE booting x86 clients
class "PXEBoot" {
  option dhcp-class-identifier "PXEClient";
  filename "install_test_ai_x86";
  next-server 192.168.0.1;
}
        
# This is a very basic subnet declaration
subnet 192.168.0.0 netmask 255.255.255.0 {
  range 192.168.0.2 192.168.0.100;
  option routers 192.168.0.1;
}