Dynamic IP addressing for LSF hosts

DHCP (Dynamic Host Configuration Protocol) enables individual computers on an IP network to extract their configurations from particular machines (DHCP servers) that have no exact information about the individual computers until they request the information. This reduces the work necessary to administer a large IP network. The most significant piece of information distributed in this manner is the IP address.

How LSF works with dynamic IP addressing

LSF hosts running Windows can be configured as DHCP clients, which means their IP address is dynamic. Users who dial in or connect from a remote location might be assigned a different IP address with each connection.

The DHCP server issues an IP address to the LSF host, but LSF gets the IP address from DNS (Domain Name System). A WINS (Windows Internet Naming Service) server synchronizes information between the DHCP and DNS servers.

The IP address should not be changed while there are active TCP/IP connections with the host, for example, while installing LSF or running LSF commands. Normally, the IP address is maintained until the host is restarted or until the network connection is broken.

If an LSF client host is assigned a new IP address, wait for WINS to update DNS before using that host to run LSF.

LSF client hosts

LSF client hosts can be DHCP clients and can change their IP addresses anytime in a running cluster.

LSF server hosts

Installing dynamic hosts on Windows allows support for dynamic IP addressing for LSF server hosts using DHCP.

LSF server hosts can be DHCP clients and can change their IP addresses anytime in a running cluster. The management host also saves the server host IP address.

Set up DHCP clients

Before you begin

To use DHCP with LSF, your system must include all of the following:
  • DHCP server
  • WINS server
  • DNS server
  • LSF hosts acting as DHCP clients

    Install Microsoft DNS server and WINS server on the same machine.

Procedure

  1. Configure a short cache timeout value on the WINS server.

    The Cache Timeout Value for the WINS Lookup of the DNS should be as short as possible (the 10-minute default may be acceptable, but this should not be increased).

  2. Enable dynamic IP addressing for the LSF cluster.
    1. Configure the following parameter in lsf.conf: LSF_DHCP_ENV=Y
    2. Reconfigure the cluster: 
      lsadmin reconfig
badmin reconfig

      LSF checks for any configuration errors. If no fatal errors are found, you are asked to confirm reconfiguration. If fatal errors are found, reconfiguration is aborted.