dhclient --version (return code: 0)
isc-dhclient-4.3.3
dhclient -HELP (return code: 1)
Internet Systems Consortium DHCP Client 4.3.3
Copyright 2004-2015 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/
Usage: dhclient [-4|-6] [-SNTPI1dvrxi] [-nw] [-p <port>] [-D LL|LLT]
[-s server-addr] [-cf config-file]
[-df duid-file] [-lf lease-file]
[-pf pid-file] [--no-pid] [-e VAR=val]
[-sf script-file] [interface]
If you think you have received this message due to a bug rather
than a configuration issue please read the section on submitting
bugs on either our web page at www.isc.org or in the README file
before submitting a bug. These pages explain the proper
process and the information we find helpful for debugging..
exiting.