The network screen, field by field
Most people blow straight past the installer's network screen on the default DHCP setting, and for a desktop VM that is fine. A server is the machine everything else connects to - its address is part of its identity. The installer gives you one clean chance to set that address permanently before the system even exists. This page explains the screen field by field, including the one trap that causes duplicate-address chaos.
During installation the network screen defaults to DHCP: the VM asks your router for an address and takes whatever it is given. That is fine for a laptop. A server is different - other machines, shortcuts, backups and your own memory all point at its address. If DHCP hands it a different address next month, everything pointing at the old one breaks at once.
Setting the address during installation is the cleanest moment to do it. The installer writes the configuration for you, the server comes up on its permanent address from the very first boot, and you never have to untangle it later.
Select the adapter on the network screen, choose Edit IPv4, and change the method to Manual. Four fields appear:
192.168.1.0/24. The /24 means the first three numbers identify the network192.168.1.50. Same first three numbers as the subnet, a last number nobody else is using1.1.1.1 after itThere is also an optional search domains field. On a home or small office network, leave it empty.
The one real trap in this screen is choosing an address your router is also handing out by DHCP. Routers typically give DHCP addresses from a pool - often the higher numbers. Pick your server's address outside that pool but inside the subnet; on many home routers something like .10 to .50 is pool-free territory, but check your router's DHCP settings page if you can.
ping it from another machine and expect no reply.Honesty matters here: a static address set in the installer is not the only correct pattern. Many administrators leave the VM on DHCP and create a reservation in the router instead - the router always gives that VM the same address, and address management stays in one place. That is a respectable approach too.
What is not fine is pure, unmanaged DHCP for anything you will connect to by address. Either fix the address here in the installer, or reserve it in the router - pick one, deliberately.
Nothing typed on this screen is carved in stone. Ubuntu Server stores its network configuration in netplan files, and the installer writes the first one from exactly what you entered here - which is why the values appear again on the summary before installation begins. If an address plan changes later, the configuration can be edited after installation; that is configuration work, covered in the companion guide.
One practical check before you press Done: read the subnet line twice. A typo here - /24 typed as /16, or a gateway on the wrong subnet - gives you a server that installs perfectly and then cannot be reached. The installer's own connection test on the mirror screen quietly depends on this screen being right.
The complete installation on a live ESXi host - creating the virtual machine and working through the installer screens exactly as they appear.
Watch Full VideoFor the very common 192.168.1.x network, the subnet is 192.168.1.0/24. The /24 suffix describes a network of 254 usable addresses where only the last number changes. If your router uses 192.168.0.x instead, the subnet is 192.168.0.0/24 - the pattern follows your router.
Yes. The installer does not require an internet connection to complete - it installs from the ISO. You can leave networking on DHCP or even disconnected and configure everything afterwards. The mirror test will fail gracefully; updates simply wait until the network is sorted out.
Both are legitimate. A static address in the installer keeps the server self-contained and reachable even if the router is replaced. A router reservation keeps all address management in one place. The only wrong answer is unmanaged DHCP for a machine other services depend on.