On 22/08/2012 14:01, Richard Reina wrote: > I have a simple perl script that every few hours pings the handful of > machines on my LAN. Lately I've sometimes been getting > > ping of 192.168.0.1 succeeded > ping of 192.168.0.7 succeeded > ping of 192.168.0.5 FAILED > ping of 192.168.0.6 succeeded > ping of 192.168.0.9 succeeded > > This machine in question has been running Centos faithfully for about six > years and no recent changes to it have been made. When I try and ping the > machine manually it works. /var/og/messages does not seem irregular. Does > anyone know know what might be the problem or what else I might check? > > > I had this problem in the past and found that it seemed to be due to iCMP rate limiting. We were pinging a lot of hosts from the monitoring system, however... But you might want to investigate here: http://www.kernel.org/doc/man-pages/online/pages/man7/icmp.7.html -- Regards, Giles Coochey, CCNA, CCNAS NetSecSpec Ltd +44 (0) 7983 877438 http://www.coochey.net http://www.netsecspec.co.uk giles at coochey.net