Windows DNSCMD commandDNS updates can be added to your failover and failback scripts by using the Windows DNSCMD command as long as dynamic updates are enabled on the DNS zone and the account running the Double-Take service is a member of the DNSAdmins security group. (See your Microsoft documentation to verify if dynamic updates are enabled.) Add the following commands to your failover and failback scripts to delete the host and reverse lookup entries and add new entries associating the source to the target.
- dnscmd DNS_server’s_FQDN /RecordDelete DNS_zone source_server_name A source_server_IP_address /f
- dnscmd DNS_server’s_FQDN /RecordDelete www.xxx.in-addr.arpa zzz.yyy PTR source_server’s_FQDN /f
- dnscmd DNS_server’s_FQDN /RecordAdd DNS_zone source_server_name A target_server_IP_address
- dnscmd DNS_server’s_FQDN /RecordAdd aaa.bbb.in-addr.arpa ddd.ccc PTR source_server’s_FQDN
| Variable | Description |
|---|---|
| DNS_servers’s_FQDN | The fully qualified domain name of the DNS server |
| DNS_zone | The name of the DNS zone |
| source_server_name | The name of the source server |
| source_server_IP_address | The IP address on the source |
| www.xxx | The first two octets of the source’s IP address. For example, if the source’s IP address is 192.168.1.108, this variable would be 192.168. |
| zzz.yyy | The last two octets, in reverse order, of the source’s IP address. For example, if the source’s IP address is 192.168.1.108, this variable would be 108.1. |
| source_server’s_FQDN | The fully qualified domain name of the source server |
| target_server_IP_address | The IP address on the source |
| aaa.bbb |
The first two octets of the target’s IP address. For example, if the target’s IP address is 116.123.2.47, this variable would be 116.123. |
| ddd.ccc |
The last two octets, in reverse order, of the target’s IP address. For example, if the target’s IP address is 116.123.2.47, this variable would be 47.2. |
For example, suppose you had the following environment.
- Full qualified domain name of the source—Alpha.domain.com
- Source IP address—192.168.1.108
- Fully qualified domain name of the target—Beta.domain.com
- Target IP address—116.123.2.47
- Fully qualified domain name of the DNS server—DNSServer.domain.com
- DNS zone—domain.com
You would add the following to your failover script to delete the host and reverse lookup entries and add new entries associating the source to the target.
|
dnscmd DNSServer.domain.com /RecordDelete domain.com alpha A 192.168.1.108 /f dnscmd DNSServer.domain.com /RecordDelete 192.168.in-addr.arpa 108.1 PTR alpha.domain.com /f dnscmd DNSServer.domain.com /RecordAdd domain.com alpha A 116.123.2.47 dnscmd DNSServer.domain.com /RecordAdd 116.123.in-addr.arpa 47.2 PTR alpha.domain.com |
You would add the following to your failback script to delete the host and reverse lookup entries and add new entries associating the source with its original identity.
|
dnscmd DNSServer.domain.com /RecordDelete domain.com alpha A 116.123.2.47 /f dnscmd DNSServer.domain.com /RecordDelete 116.123.in-addr.arpa 47.2 PTR alpha.domain.com /f dnscmd DNSServer.domain.com /RecordAdd domain.com alpha A 192.168.1.108 dnscmd DNSServer.domain.com /RecordAdd 192.168.in-addr.arpa 108.1 PTR alpha.domain.com |
See your Windows documentation or the Microsoft web site for more details on the DNSCMD command.
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