Hello ports@, I am unable to get broadcast DHCP requests to be generated on openbsd 6.6 and 6.7 using the packaged versions of monitoring-plugins, which are monitoring-plugins-2.2p8 and monitoring-plugins-2.2p9, respectively.
I have tested the package on a few different environments and it boils down to this: - unicast DHCP is working fine with something like: -i vio1 -v -t 3 -m "52:54:00:f3:e9:cb" -r 10.10.0.10 -s 10.10.0.2 -u - if the server runs something like '/usr/local/libexec/nagios/check_dhcp -i vio1', which should be a broadcast request: - packets will always exit through the first phsical ethernet interface (e.g. vio0) - no reply received - if the server runs something like '/usr/local/libexec/nagios/check_dhcp -i vio0' - if the interface has no address, a packet will not be sent at all. No local unicast addess needed with IPv4 broadcast DHCP client - if the interface has an address, no DHCP replies are ever received Unicast-based DHCP monitoring works fine, but this type of monitoring does not meet the criteria for rogue DHCP server detection. Can anyone confirm/deny this before I get an opportunity to look at the code? Thanks, -- Marcos Madeira