DHCP and Network Installation Management suggestions

The concept of dynamically assigning Internet Protocol (IP) addresses is fairly new. The following suggestions are provided to help with DHCP and Network Installation Management (NIM) interaction.

1. When configuring objects in the NIM environment, use host names whenever possible. This allows you to use a dynamic name server that updates the IP addresses when the host name is converted to an IP address in the NIM environment.
2. Place the NIM master and the DHCP server on the same system. The DHCP server has an option in the update DNS string that, when set to NIM, attempts to keep the NIM objects out of those states that need static IP addresses when those addresses change.
3. For NIM clients, set the default lease time to twice the time it takes to install a client. This allows a leased IP address to be valid during the installation. After the installation, restart the client. DHCP will be started or will need to be configured, depending on the type of installation.
4. The dhcpsd server should be responsible for both the PTR and the A DNS records. When NIM reinstalls the machine, the file containing the RSA is deleted, and the client cannot update its records. The server updates the system records. To do this, change the updatedns line in /etc/dhcpcd.ini to:

   updatedns "/usr/sbin/dhcpaction '%s' '%s' '%s' '%s' '%s' NONE NONIM"

   In the /etc/dhcpsd.cnf file, change the updatedns line to:

   updatedns "/usr/sbin/dhcpaction '%s' '%s' '%s' '%s' '%s' BOTH NIM"

   Note: When a NIM object is placed into the BOS installation-pending state, the dhcpsd server might pass arguments that are different from those originally intended. Minimize the time the client is in this pending state to avoid this situation.