sf-ip-monitor extension periodically checks the external IP of current server for changes and notifies administrator about such changes.
This extension is meant for monitoring services connected to Internet through DSL or similar lines, with dynamic IP, which changes very rarely. Such Internet connections are perfect choice for particular service types, eg. distributed backup services, where it is acceptable that the service is inaccessible for users for a few minutes each few months/years. And this extension notifies owner that IP just changed and DNS needs to be updated asap.