DHCP

A NetWare 5 DHCP server automatically assigns IP addresses and other configuration information to clients upon request or when the clients are restarted. Automatic assignment of configuration information reduces the amount of work required to configure and manage a large IP network.

Furthermore, integrating DHCP with NDS enables you to enter all configuration information into one distributed database. This greatly simplifies network administration and provides for the replication of DHCP configuration information.

DHCP provides for both static and dynamic configuration of IP clients. Static configuration enables you to assign a specific IP address and configuration to a client with a specific MAC address. When DHCP assigns IP addresses dynamically, IP clients are assigned an IP address that is chosen from a range of available addresses. You can use dynamic address assignment when you are not concerned about which IP address a particular client uses. Each IP client that requests an address assignment can also use the other DHCP configuration parameters.

DHCP can limit the amount of time a DHCP client can use an IP address. This is known as the lease time. You can use the lease time to allow a large number of clients to use a limited number of IP addresses.

DHCP is based on BOOTP and maintains some backward compatibility. Novell DHCP servers can be configured to respond to requests from BOOTP clients.

Novell DNS/DHCP Services provides the following DHCP features:

• All DHCP configuration is done in NDS, facilitating enterprise-wide management.
• DHCP options can be set at three levels:
  • Enterprise level
  • Subnet level
  • Specific client level

• The configuration utility has import/export functions that support
  • Populating NDS from an existing Novell DHCP Server 2.0 DHCPTAB file or from a BOOTPTAB file (for Novell BOOTP)
  • Saving configuration out of NDS

• You can configure the level of SNMP event trap generation using the DNS/DHCP Management Console for all events, major events only, or no events.
• Client assignment policy options (to support mobile clients that move around the network) include
  • Allow Duplicate
  • Delete Duplicate
  • No Duplicate

• You can use the DNS/DHCP Management Console to maintain a hardware exclusion list to deny service to unwanted devices by their MAC addresses.
• The DHCP software updates NDS to record all address assignments to LAN clients.
• You can use Dynamic DNS (DDNS) to update DNS with information about addresses assigned and rescinded.
• The DHCP software enables the server to cache addresses and other configuration information from NDS for quick response.
• The DHCP software has one DHCP server NetWare Loadable Module^TM (NLM^TM) file that supports both LAN and remote access clients.
• You can configure the DHCP server to ping an address to verify that no other device is using it before assigning the address to a client.
• Provides fault tolerance as follows:
  • A server can survive a temporary local NDS service outage and recover automatically.
  • DHCP configuration is replicated like other NDS data.

• DHCP auditing can help diagnose problems. Each incidence of address deletion, addition, and rejection is recorded.

Novell DNS/DHCP Services supports the features that were previously provided by Novell DHCP Server 2.0 and supports the standards of the RFCs in the following list:

• RFC 2131---Dynamic Host Configuration Protocol
• RFC 2132---DHCP Options and BOOTP Vendor Extensions
• RFC 2241---DHCP Options and Novell Directory Services
• RFC 2242---NetWare/IP Domain Name and Information

Novell DNS/DHCP Services also supports the BOOTP standards of the RFCs in the following list:

• RFC 1497---BOOTP Vendor Information Extensions
• RFC 1534---Interoperation Between DHCP and BOOTP
• RFC 1542---Clarifications and Extensions for the Bootstrap Protocol

Refer to DHCP Options for a list of all supported DHCP options.