Dhcp

Debian 12, no DHCP. Set a static IPv4 on the Ethernet interface.

Identify the interface:

ip link

Assume it’s enp0s3 (use whatever you actually have).

Configure static IP (NetworkManager NOT used, default ifupdown):

Edit:

sudo nano /etc/network/interfaces

Add:

auto enp0s3 iface enp0s3 inet static address 192.168.1.10 netmask 255.255.255.0

No gateway needed if it’s just internal / point-to-point.

Restart networking:

sudo systemctl restart networking

Verify:

ip addr show enp0s3

If NetworkManager is installed and active (common even on headless):

nmcli device status nmcli con show

Set static IP:

nmcli con mod "Wired connection 1" ipv4.method manual ipv4.addresses 192.168.1.10/24 nmcli con up "Wired connection 1"