Update DNS via HTTP
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This update method can be used to send DNS updates via HTTP to a dynamic IP services such as dyndns.org or WebReactor Networks.

When using this update method, you must specify an update URL, and optionally a user ID and password for HTTP authentication. A success text can also be specified evaluating the response from the dynamic IP service.

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.  

And finally it sends a HTTP request for the update UURL - replacing any $IP$ tag with the server IP address as per the monitoring results (1), and any $DOM$ tag with the domain name. The result from your dynamic IP service provider might come as a web-page with status information on the update request. Simple Failover let you specify a case-sensitive Success text string. Simple Failover will read the status reply from your provider and see if it can find the exact information on the page. You may also include HTML tags to ensure an exact match.

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