It's recommended to use this option since it doesn't really produce too much output but will greatly help in resolving a problems if any. When system boots dhcpcd will use cache to request the same IP address from DHCP server which was assigned before the system went down. If dhcpcd is not running, the flag is ignored and dhcpcd follows the normal startup procedure. Requests broadcast response from DHCP server.
Forces dhcpcd to calculate checksum on received packets.
Forces dhcpcd to set domainname of the host to the domainname option supplied by DHCP server. By default dhcpcd will NOT set domainname of the host to the domainname option received from DHCP server. Forces dhcpcd to set hostname of the host to the hostname option supplied by DHCP server. By default dhcpcd will NOT set hostname of the host to the hostname option received from DHCP server. Test case, when dhcpcd goes through the DHCP negotiation sequence but doesn't actually configure the interface or otherwise change anything on the system.