A major new feature in Servers Alive 6.1 is Remote Agent support.
The Remote Agent is a small application that accepts requests from Servers Alive, performs a check (command) and provides information about the result back to Servers Alive.
A Remote Agent enables you to perform checks without needing to open non-secure protocols in your firewall. The agent runs on the remote system, and Servers Alive connects to it securely in order to request a check from the agent.
In the previous versions of Servers Alive all the checks were performed agent-less. This method has big advantages in most cases. However in some cases where you want to check systems that are in a secured network, it's not always possible to do the checks within the normal protocols.
For example most DMZs don't allow NetBIOS traffic, which means that all checks that are based on NetBIOS simply won't work. With the remote agent check we can communicate with the remote system using 1 port and a SSH-like (encrypted) protocol.
The agents are freely available from our website. Within the Enterprise edition you can by default define 2 of those agents (more can be added by purchasing extra remote-agent licenses). We have a Windows agent (runs as service) and have a agent for *nix systems (binary and source-code).