Technology Briefing: DHCP

What to Look For
Managers seeking a DHCP solution need to consider several functions, including:

  • Configurable parameters — depending on the DHCP version, managers can set such parameters as the lease time, establish groups of users with different parameters, and enhance security by limiting the MAC addresses of devices allowed to access the network. In addition, support for BOOTP devices and other types of named servers can increase the flexibility of DHCP.
  • Multiple server support — coordinating DHCP across multiple servers requires the servers to synchronize the IP allocation tables. Support for this function helps ensure that the network operates correctly and that multiple devices do not accidentally receive the same IP address.
  • Administration features — as is the case with most network administration utilities, managers generally prefer a centralized approach. For networks with multiple servers or geographically dispersed networks, centralized control is necessary. Support for setting parameters through scripts and programming languages also help managers maintain a network more effectively, and most managers prefer a graphical interface.
  • Import capability — if a network already supports static IP addresses, the ability to import these addresses can simplify the DHCP conversion. This feature also helps managers maintain a network that has group of IP addresses that change infrequently.
  • Global settings — managers need to change parameters in DHCP as the network evolves. The ability to apply these changes to every session or groups of sessions eases the configuration process.
  • Reports — an audit trail that includes a log of the IP addresses granted allows the manager to monitor the network operation, enhance security, and anticipate problems.

The Bottom Line
Most network managers like the idea of DHCP, but they fear the complexity of setting up such a system. The decision of moving to DHCP revolves around time. For managers with a static network, DHCP provides little benefit. However, managers that spend time maintaining complex IP tables and managers that expect to expand their networks in the future will want to seriously considering implementing this standard.

Gerald Williams serves as Director of Quality Assurance for Dolphin Inc., a software development company. Williams has extensive background in technology and testing, previously serving as Editorial Director with National Software Testing Labs (NSTL), Executive Editor with Datapro Research, and Managing Editor of Datapro’s PC Communications reference service.

Each CrossNodes Briefing is designed to act as a reference on an individual technology, providing a knowledge base and guide to networkers in purchasing and deployment decisions.