OpManager is a centralised network monitoring tool that runs on Windows, Linux or Solaris. It uses SNMP and a number of standard protocols (HTTP, FTP and suchlike) to interrogate whatever devices you point it at and gather the data on a centralised server; the data is examined using either a proprietary client or a Web GUI, either from the central machine itself or, more likely, from a remote workstation.
The installer gives you the option of putting either the entire suite, or just the client package, on the current machine; we ran the whole package on our lab server and chose to install just the client application on a desktop PC. We ran the server module on our 1GHz Pentium III server and installed the client on a Dell laptop.
Once up and running, OpManager can auto-discover devices on the network. Once it's found what's there, it lays it out as a set of icons, each with a hint as to what the system is (eg. the Windows logo) and a little flag showing whether it's functioning properly. Each device can be further configured to (say) set its SNMP access codes and/or specify what type of device it is; in the latter case you're given a longish list of possible device types but the only vendor with a decent number of models listed is Cisco, which is a shame.
As well as the default layout, devices can be organised in user-definable groups, or Business Views. You can define as many of these as you wish, and collect the monitored systems into comprehensible sets. The system also has a couple of pre-defined collections: Network Views (where systems are split into sections based on their IP address/subnet mask) and Infrastructure Views (where they're split into collections such as servers, desktops, printers, routers and switches). The latter is a bit irritating because you can't change a device's type (so if it puts your firewall into the 'servers' pot and you'd prefer it in 'routers', that's just tough) but it does make a reasonably decent first stab at the categorisation exercise.
As you'd expect, OpManager will monitor devices on a user-defined schedule and can alert you when problems arise. As well as basic ping monitoring, there's a set of pre-defined protocols that you can specify for monitoring - so you can watch port 80 on a Web server, for example, or port 25 on an SMTP server. There are 20 or so predefined service types, but you can easily add your own by simply entering a name, a port number and the number of seconds within which a connection should be achievable. It's a shame, actually, that OpManager doesn't follow the example of packages such as AwakE, which we reviewed recently, by digging into each protocol in more depth to ensure not just that the connection can be made but that a protocol-specific interchange between monitor and server can take place.
The monitoring and alerting side of the system is quite cleverly done. You get the usual mechanisms for actually delivering the alerts to the system manager (email, SMS, or execution of an external application) but the developers have clearly spotted one of the main issues with this type of system - namely that if, say, a switch fails, you're going to get alerts not just for that switch but for everything that's the other side of it. You can therefore configure OpManager to only monitor device A if device B is known to be working - so if device B is a switch to which device A is connected, you'll be told that B is poorly but not bombarded with alerts about A as well. The other neat bit with alerting is that you can define Notification Profiles - sets of criteria and actions that can be attached to different devices. So you could have one called Web Problems which monitors the Web service on a collection of servers and emails the Web administrator of failures, and one called 'Email Problems' which monitors the SMTP service on a different set of machines and SMSs the email administrator if something fails.
OpManager's user interface has the feel of a professionally-written package, although we thought performance was a bit sluggish on our 1.4GHz Pentium Mobile laptop. All in all it's a usable product with a modest price tag which, while we'd like to see more advanced service polling, offers a useful set of features to the network manager.
There are dozens of packages like this on the market, each with its own particularly neat features (and some inadequacies). Do shop around for a package where the best bits match your particular requirements most closely.