ifconfig_em0="DHCP" enables DHCPv4 only on interface em0.
ifconfig_em0_ipv6="DHCP" enables DHCPv6 only on interface em0.
dhcpcd_enable="YES" enables both DHCPv4 and DHCPv6 on all interfaces.
In addition to the normal review cycle, given I am only a ports committer (I don’t have a src commit bit), I will need this to be endorsed and approved by a src committer.