check_dhcp

Warren Block wblock at wonkity.com
Fri Jul 25 03:14:28 UTC 2014


net-mgmt/monitoring-plugins has a check_dhcp program used to test the 
availability of a remote DHCP server.  It has BSD-specific code, but 
seems fairly dated and only works when all supposedly optional 
parameters are given.  However, it does work on a normal machine:

   OK: Received 1 DHCPOFFER(s), 1 of 1 requested servers responded, max lease time = 600 sec.

But it does not work inside a jail, seeing no offers:

   CRITICAL: No DHCPOFFERs were received.

Raw sockets and bpf are enabled in the jail.  dhclient in the jail can 
actually get a lease.  Is there anything else that needs to be 
configured to allow this to work in a jail?



After 'make -C /usr/ports/net-mgmt/monitoring-plugins', the code in 
question is check_dhcp.c in
work/monitoring-plugins-monitoring-plugins-b5611ea/plugins-root.  It 
gives these type of errors:

   % ./check_dhcp -s 192.168.1.1
   Error: if_nametoindex error - Device not configured.

   % ./check_dhcp -s 192.168.1.1 -i em0
   Error: Couldn't get hardware address from em0. sysctl 2 error - No such file or directory.

After adding -m <jail card's MAC>, it gives no errors but never sees a 
response.


More information about the freebsd-jail mailing list