2. Nagios
Nagios is the open-source network monitoring software of choice because it is widely used
and has a big user and developer community. Its users encompass ISPs, governments, as well as big
enterprises, such as Yahoo, Amazon, Google [16]. Nagios is proven to be scalable for a large network
with as many as 100,000 hosts and 1,000,000 services [16]. In addition, it has received several awards
from the Linux and networking communities, such as the Infoworld's Best of Open Source Software
(BOSSIE) 2008 Award under the "Server Monitoring" category, and the Linux Journal Reader's Choice
2009 award for "Favorite Linux Monitoring Application" [14].