1) isc-dhcp-client doesn't do IPv6 well and cannot handle a dual-stack case at all.
2) isc-dhcp-client is EOL upstream.
3) https://bugs.launchpad.net/ubuntu/+source/dhcpcd5/+bug/2019191
1) isc-dhcp-client doesn't do IPv6 well and cannot handle a dual-stack case at all.
2) isc-dhcp-client is EOL upstream.
3) https:/ /bugs.launchpad .net/ubuntu/ +source/ dhcpcd5/ +bug/2019191