Network Monitoring with SmokePing
Our remote sites are connected by a Managed MPLS. While a managed service frees us from the headache of maintaining the equipment and configurations, it also prevents us from troubleshooting properly. The only tools provided are bandwidth utilization reports, which currently, do not work.
After my Kaspersky Antivirus rollout, remote users started to complain about slow network speeds. Further investigation intermittently showed high latency (~200ms - 400ms) on our T1 lines. A phone call to our service provider resulted in the usual: "Call us when it is happening."
I decided to set up SmokePing, an open source network monitoring utility. I installed it on an Ubuntu Server using apt and with some minor configuration, it was running smoothly. It presents ping tests in various graphs, which you can drill down to specific points and see what the latency is at that time. I have it set up to run 20 pings to each of my remote routers every minute. After monitoring for a few days, I was able to narrow down that our latency was caused by remote Kaspersky clients connecting to the main server for updates. It was maxing out the links (which, if my utilization reports worked, I would have been able to determine).
SmokePing can be configured to monitor all kinds of network services as well. It is an essential tool in the OpenSource Network Administrator's toolkit.
A word of warning, if you change your ping settings, you need to delete some rrd files associated with SmokePing, which will destroy your history.