[CentOS] internet connection tester script

Fri Jan 28 12:19:06 UTC 2011
John R Pierce <pierce at hogranch.com>

On 01/28/11 3:28 AM, kellyremo wrote:
> bix.hu and www.yahoo.com are "pingable" test sites.
> could not be pinged [firewall drops all icmp]

what sort of firewall drops packets on localhost ?!?

yahoo.com is probably a poor choice of targets, as its a widely 
distributed group of servers, and you likely will be pinging different 
servers at different times, maybe even in different parts of the world.  
I would instead suggest using a target at your ISP or backbone provider.

btw, dropping 'all icmp' is bad practice.  Internet Control Message 
Protocol is used for a number of things, including informing 
applications when a host or port is not accessible.  if you drop this, 
you instead hang for minutes waiting for a response instead of quickly 
getting back a 'target {host|port} not reachable' error.

anyways, if you drop all ICMP, you won't get any pings from anywheres.