check-host-alive reporting host down but it's not

[brandon.pal]

I have one host that check-host-alive is showing as down.

CRITICAL - x.x.x.x: Host unreachable @ x.x.x.x. rta nan, lost 100%

From the Nagios server if I run the check manually I get:

OK - x.x.x.x: rta 0.308ms, lost 0%|rta=0.308ms;3000.000;5000.000;0; pl=0%;80;100;;

From Nagios if I click Ping this host it works and traceroute.

check-host-alive is working for all my other hosts but not this one.

Any ideas?

[abrist]

Is the Host Address for the check in question an IP or a DNS name? If it is a name, can you ping the name from the cli?