check_dhcp problem on centos 5.3



have a problem with check_dhcp. Opened ports udp 67 and 68 on firewall, but check still doesn’t work. If firewall is off, it works fine.
Looked around at forums, but i havent find a solution, what to open or do. Plz, help i really need this check.



Solved, thx to Rene.Make install didn’t set the execution
permissions for all users. So if nagios runs as user daemon one need to make
chmod a+x check_dhcp