Long option and short option achieve the same thing, which requires an IP address. I have tried it out, on two separate nagios boxes, one running Debian, the other, Redhat. Why don't you copy and paste the results from shell to prove me wrong? <div class="gmail_quote">On Thu, Jun 7, 2012 at 12:26 PM, Holger Weiß <<a href="mailto:holger@cis.fu-berlin.de" target="_blank">holger@cis.fu-berlin.de</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> * Travis Runyard <<a href="mailto:travisrunyard@gmail.com">travisrunyard@gmail.com</a>> [2012-06-07 09:56]: <div class="im">> <a href="http://nagiosplugins.org/man/check_ping" target="_blank">http://nagiosplugins.org/man/check_ping</a> > > <host_address> = IP address. NOT hostname. </div>Indeed, "host_address" seems to suggest an IP address. Then again, the long option is called "--hostname" :-) Anyway, you can specify either an IP address or a hostname. Why don't you simply try it out? > $HOSTADDRESS$ - Address of the host. This value is taken from the > *address* directive in the host definition You neither have to hand over the $HOSTADDRESS$ to check_ping (you could use the $HOSTALIAS$ or whatever you like instead), nor do you have to specify an IP address as the "address" of a host.š We use only hostnames in our Nagios configuration. Holger š "Normally, this is an IP address, although it could really be anything you want" -- <a href="http://nagios.sf.net/docs/3_0/objectdefinitions.html#host" target="_blank">http://nagios.sf.net/docs/3_0/objectdefinitions.html#host</a> <div class="HOEnZb"><div class="h5"> ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. <a href="http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/" target="_blank">http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/</a> _______________________________________________ Nagios-users mailing list <a href="mailto:Nagios-users@lists.sourceforge.net">Nagios-users@lists.sourceforge.net</a> <a href="https://lists.sourceforge.net/lists/listinfo/nagios-users" target="_blank">https://lists.sourceforge.net/lists/listinfo/nagios-users</a> ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null </div></div></blockquote></div>