Can't delete an IP address from Plesk: cannot delete main IP on interface

Symptoms

• An IP address can't be removed from Plesk

  Error: ifmng failed: 203.0.113.2: cannot delete main IP on interface

• It's not the server's main IP address

  # plesk db "select ip_address,main from IP_Addresses"
  +---------------+-------+
  | ip_address | main |
  +---------------+-------+
  | 203.0.113.2 | false |
  | 203.0.113.3 | true |
  +---------------+-------+
  2 rows in set (0.00 sec)

Cause

The IP address from the error was manually configured on the server on the non-alias network interface. Plesk cannot delete such an IP address to avoid situations where the server has no IP address left.

Resolution

The IP address needs to be removed from the system directly first, and then it can be removed from Plesk.

1. Connect to the server via SSH
2. Remove the IP address from the interface using the native operating system commands
3. Log into Plesk
4. Go to Tools & Settings > IP Addresses and press Reread IP
5. Select the IP address, press Remove, and confirm