Oracle^® ILOM Administrator's Guide for Configuration and Maintenance Firmware Release 4.0.x

Example: Set Up DDNS Configuration

This example describes how to set up a typical DDNS configuration.

Assumptions:

The following assumptions apply to this DDNS configuration example:

• There is a single server that handles both DNS and DHCP for the network on which the SP resides.

• The SP network address is 192.168.1.0.

• The DHCP/DNS server address is 192.168.1.2

• The IP addresses from 192.168.1.100 to 192.168.1.199 are used as a pool to provide addresses to the SP and other clients.

• The domain name is example.com.

• There is no existing DNS or DHCP configuration in place. If there is, use the .conf files in this example as a guideline to update the existing configuration.

You can use the following steps and sample files provided here, with site-specific modifications, to set up your own DDNS configuration.

1. Install the bind9 and dhcp3-server packages from the Debian distribution.

   Installing the dnsutils package provides access to dig, nslookup, and other useful tools.

2. Using dnssec-keygen, generate a key to be shared between the DHCP and DNS servers to control access to the DNS data.
3. Create a DNS configuration file named /etc/bind/named.conf that contains the following:

   options {
     directory "/var/cache/bind";
     auth-nxdomain no;    # conform to RFC1035
     listen-on-v6 { any; };
   };
   // prime the server with knowledge of the root servers
   zone "." {
     type hint;
     file "/etc/bind/db.root";
   };
   // be authoritative for the localhost forward and reverse zones, // and for broadcast zones as per RFC 1912
   zone "localhost" {
     type master;
     file "/etc/bind/db.local";
   };
   zone "127.in-addr.arpa" {
     type master;
     file "/etc/bind/db.127";
   };
   zone "0.in-addr.arpa" {
     type master;
     file "/etc/bind/db.0";
   };
   zone "255.in-addr.arpa" {
     type master;
     file "/etc/bind/db.255";
   };
   // additions to named.conf to support DDNS updates from dhcp server
   key server.example.com {
     algorithm HMAC-MD5;
     secret "your-key-from-step-2-here"
   };
   zone "example.com" {
     type master;
     file "/etc/bind/db.example.com";
     allow-update { key server.example.com; };
   };
   zone "1.168.192.in-addr.arpa" {
     type master;
     file "/etc/bind/db.example.rev";
     allow-update { key server.example.com; };
   };
   

4. Add empty zone files for the local network.

   Empty zone files should be named /etc/bind/db.example.com and /etc/bind/db.example.rev.

   Copying the distribution supplied db.empty files is sufficient; they will be updated automatically by the DNS server.

5. Create a /etc/dhcp3/dhcpd.conf file that contains the following:

   ddns-update-style interim;
   ddns-updates      on;
   server-identifier server;
   ddns-domainname   "example.com.";
   ignore client-updates;
   key server.example.com {
     algorithm hmac-md5;
     secret your-key-from-step-2-here;
   }
   zone example.com. {
     primary 127.0.0.1;
     key server.example.com;
   }
   zone 1.168.192.in-addr.arpa. {
     primary 127.0.0.1;
     key server.example.com;
   }
   default-lease-time 600;
   max-lease-time 7200;
   authoritative;
   log-facility local7;
   subnet 192.168.1.0 netmask 255.255.255.0 {
     range 192.168.1.100 192.168.1.199;
     option domain-name-servers 192.168.1.2;
   }
   

6. After completing Steps 1 through 5 above, run the /etc/init.d script to start the DNS and DHCP servers.

   Once the servers are running, any new Oracle ILOM SPs configured for DHCP will be automatically accessible using their host name when they are powered on. Use log files, dig, nslookup, and other utilities for debugging, if necessary.

References

For more information on the Linux DHCP and DNS servers used in this example, see the Internet Systems Consortium web site at: http://www.isc.org/