Unable to add IP address in Plesk: The IP address is not configured properly

Symptoms

• The IP address can be added to Plesk
• The Server OS is Debian/Ubuntu-based
• Clicking Reread IP in Tools & Settings > IP Addresses marks the IP address as not configured properly:

This IP address is not configured properly

• Interface names in netplan configuration files are different:

# cat /etc/netplan/01-netcfg.yaml
...
  ethernets:
    ens18:
      match:
      macaddress: 00:00:5E:00:00:00
...        

# cat /etc/netplan/10-plesk.yaml
...
  ethernets:
    eth0:
      addresses:
...

Cause

Netplan is unable to add an IP address to the network interface since the Interface Name differs from the IP address mapping that is missing.

Resolution

• Remove broken IP addresses from Plesk
• Delete file /etc/netplan/10-plesk.yaml
• Rename the interface name in /etc/netplan/01-netcfg.yaml in accordance to Plesk configuration file (10-plesk.yaml) and apply netplan changes:

# cat /etc/netplan/01-netcfg.yaml
...
 ethernets:
  eth0:
      match:
        macaddress: 00:50:56:45:1b:82

# netplan try

# netplan apply

• Add IP addresses to Plesk anew