DHCP Failover Strategy

Share

Last Review: August 9, 2010
Product(s): Windows Server 2003 / 2008 / 2008 R2

DHCP is best deployed on a Windows Server to integrate automatically with DNS. However, unlike DNS Servers there are no primary and secondary roles or replication for DHCP Servers. To setup DHCP failover:

  1. Create DHCP Scopes of Main and Backup on two separate servers with the full IP address ranges such as 192.168.100.1 - 192.168.100.254.

  2. On Main, exclude range 192.168.100.1-25 for servers and printers and 192.168.100.128-254 for desktops on Backup.

  3. On Backup, exclude 192.168.100.1-127.

The concept is that if one DHCP Server fails, DHCP lease duration and the available lease addresses on the failover DHCP Server are ample to serve more desktops that in one scope until the failed DHCP Server is restored. Scope Options for DNS and Router should be the same on both DHCP Servers.