If you are using a non-Microsoft DNS server (such as Unix) or if you are in a non-domain configuration (such as a workgroup), when Double-Take Availability failover occurs, DNS is not automatically updated. If the end-users use DNS to resolve server names and the source IP address was not failed over to the target, additional DNS updates will be required because the host records for the source will remain intact after failover. You can automate this process by scripting the DNS updates in the failover and failback scripts.
If you are protecting an application, you can configure the Application Manager not to check for Microsoft DNS or you can start the Application Manager from the command line and specify the /altdns option after your application switch.
For other workload protections, one option is to use a BIND DNS client for DNS scripting. The following steps provide an example of how you can use a BIND DNS client for DNS failover and failback scripting. You may need to modify this example to fit your environment.
nsupdate.exe "c:\install_location\dnsover.txt" |
update delete source_server_name.fully_qualified_domain_name.com A update add target_server_name.fully_qualified_domain_name.com 86400 A target_server_IP_address send |
nsupdate.exe "c:\install_location\dnsback.txt" |
update delete target_server_name.fully_qualified_domain_name.com A update add source_server_name.fully_qualified_domain_name.com 86400 A source_server_IP_address send |