Using Standby Servers

  • Article

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

A standby server and its scopes are not activated for use under normal conditions, and are activated by the administrator only when needed, such as when a DHCP server fails or is taken offline for an extended period of time. Standby servers require manual administration to ensure failover transition, and therefore might not be as effective as other failover methods, such as split scopes and clustered servers.

To use a standby configuration, configure an additional DHCP server to server as a backup if the primary server goes offline. You can either configure the standby server to be identical to your primary DHCP server or configure the standby server with unused scopes to temporarily replace the primary DHCP server.

If you are configuring the standby server with the identical scope to your primary DHCP server, you must implement server-side address conflict detection to prevent the assigning of duplicate addresses.

Important

  • Because server-side conflict detection uses Address Resolution Protocol (ARP) and Internet Control Message Protocol (ICMP) messages to detect conflicts, Internet Connection Firewall (ICF) or other firewalls that are installed on clients on your network might interfere with conflict detection.

For more information about backing up your DHCP servers, see "Backing up the DHCP databaseBacking up the DHCP database" or "Netsh commands for DHCP" in Help and Support Center for Windows Server 2003.