Hi,
 We have tens of networks(VLANs) in data center with a central Linux DHCP 
server. each network has their router to do the DHCP relay. So, the DHCP 
server's configuration files has tens 'subnet' statements.
Because PXE booting is standard in whole data center, there are also thousands 
of static MAC-IP mapping 'host' statements in dhcp configuration.
The big challenge with a central dhcp server is how to detect typo in the 
thousands of MAC-IP 'host' statements? -- a single char/digit typo here will 
fail a PXE booting or download wrong post-installation snippets.

 Is there a tool to validate all 'host' statements from another Linux box? 

I tried nagios check-dhcp plugin, with a series of real MAC addresses(for hosts 
in other different networks). Surprisingly, the IP address came back were not 
the static IP addresses in 'host' statement, but dynamic addresses in the pool 
defined for this particular network (where I ran check-dhcp from).
check_dhcp was run with the following arguments:

/usr/lib64/nagios/plugins/check_dhcp --verbose --server=<my_dhcp_server> 
--interface=eth0 --mac=<real_Mac_for_servers_in_diff_networks> --unicast
remove --unicast doesn't help but just see more DHCP replys.
Interestingly, with a same MAC address, and the above same command, from two 
Centos boxes on different network there will be different dynamic IPs! instead 
the static IP defined with 'host' statement.  

So, how can we validate static IP assignment? Thanks.
Best,David,

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