hadr_local_host - HADR local host name configuration parameter

This parameter specifies the local host for high availability disaster recovery (HADR) TCP communication.

Configuration type
Applies to
  • Database server with local and remote clients
  • Database server with local clients
Parameter type
  • Configurable1
  • Configurable by member in a Db2® pureScale® environment
Upgrade Note
  • If you are upgrading from a Db2 Version 9.8 Fix Pack 4 pureScale environment or earlier, the value of hadr_local_host is set to the value on member 0.

Either a host name or an IP address can be used. If a host name is specified and it maps to multiple IP addresses, an error is returned, and HADR will not start up. If the host name maps to multiple IP addresses (even if you specify the same host name on primary and standby), primary and standby can end up mapping this host name to different IP addresses, because some DNS servers return IP address lists in non-deterministic order.

A host name is in the form: myserver.ibm.com. An IP address is in the form: "".

If this host resides in a private network behind a NAT (Network Address Translation) device, you can specify both the internal and external host names (or IP addresses), separated by the vertical bar |, as shown in the following example:
internal_name | external_name
For more details, refer to HADR and Network Address Translation (NAT) support.

Usage Notes

  • If your primary and standby start but do not connect to one another, and no error indication appears in the Db2 diagnostic log, it could be due to subtle issues in the host name resolution. If you configured HADR using host names, try again using the IP addresses instead.
1 Changes to this parameter take effect on database activation. If the database is already online, you can have changes take effect by stopping and restarting HADR on the primary database.