Update DNS via scripting
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If you choose this DNS update method, Simple DNS plus will simply call a procedure in your script file each time a DNS update is required.
You specify the script file and script language in the Options dialog (Tools menu / Options) on the Scripting tab.

Simple Failover performs the following steps to check and update DNS:

First, based on the monitoring results, it figures out what the DNS records should be for the Server Set domain name:
- It will configure a single A-record for the first functional server (round robin is not available for this DNS update method).  
- If none of the servers were functional, then Simple Failover will assume that the problem must be local, and it will configure an A-record as if the first server did respond correctly.  
- If the Server Set Failed Polls Accepted setting is greater than zero, then each server is considered functional, until it has been found non-functional more times than this number.  

Then it sends a DNS request to the DNS server to check the current DNS A-records for the Server Set domain name.
If this is already what it should be (1), then the process stops here as there is no need to update anything.  

Next it sends a DNS request to the DNS server to get the SOA-record for the Server Set domain name.
This will return the DNS zone name that the domain name belongs to (needed for the update process).  

And finally it executes the script procedure SFOUpdateDNS with the following 4 parameters:
- DNSServerIP - The IP address of the DNS server.  
- ZoneName - The DNS zone which the Server Set domain name belongs to.  
- DomainName - The Server Set domain name.  
- IPAddress - The server IP address as per the monitoring results (1).  
It is then up to your script to make the appropriate updates to the DNS server.  

While communicating with the DNS server, Simple Failover may encounter communication errors (winsock error), time outs, or unexpected responses. Such problems will be logged, listed in the problems list, and invoke e-mail and script notifications.