We discovered Cacti at work a few years ago, and yes it did have a little bit of an installation learning curve, but that was before we found CactiEZ. Its a linux distro based off of centos that uses a kickstart script to auto-install a Cacti server with a ton of extra features. Via its default packages and the nifty cacti plugins, it adds support for lots of features not found in Cacti normally. For instance complete Netflow integration (it captures, allows you to query the data through the Cacti UI, and if you want, it can even redirect the flows to NTop which is running by default). It sports remote syslog monitoring, so you can have your servers(Windows and Linux) all log to one place, and then easily query the events through a GUI with alerting features. Then you have a few minor things like network auto-discovery, mactrack(which specific switchport and IP is at), weathermap(network diagram with realtime bandwidths), a simple device up/down monitor, thresholding(alerts for breaches of set values for ANY data source). Even comes preinstalled with Webmin for all the non-linux savvy technicians.

Now we have a complete restore procedure based upon this CD which allows us to get a dead Cacti server up and running in under 20 minutes (5-7 minutes to install CactiEZ on a new machine, 13-15 minutes to restore the database and rrd files from backup). All-n-all its pretty nifty, especially for the price. Who doesn't like free?