[CentOS] Recommendation On Ping And Alert Tool

For depending on your needs, (how many hosts, what all you need
monitored) Nagios (http://www.nagios.org/) Mon
(http://www.kernel.org/pub/software/admin/mon/html/) or Zabbix
(http://www.*zabbix*.com/) may do the trick.  They are resonably
different from each other, while having a converging set of features. 
Each handles considerably more than ping, so they may be overkill for you.

Jacob Leaver
Senior Systems Administrator
ReachONE Internet