Wrong IP address from DHCP client on Ubuntu 18.04

dhcp ubuntu ip

The cause of the problem is that the built-in network config of Ubuntu 18.04 no longer uses the NIC Mac address as the default id for DHCP requests.

It can be restored by adding dhcp-identifier: mac to the configuration in the /etc/netplan/xxx.yaml (cloud-init) file as follows:

network:
    version: 2
    ethernets:
        ens3:
            dhcp4: true
            dhcp-identifier: mac

Reference:
https://superuser.com/questions/1338510/wrong-ip-address-from-dhcp-client-on-ubuntu-18-04

Written on August 21, 2019