Manual Internet Configuration on Debian Using Only ip and Low-Level Tools

This guide explains how to manually configure an internet connection on a Debian-based system using only low-level tools — perfect for headless setups, stripped systems, or recovery environments where NetworkManager or higher-level tools aren’t available.

1. Identify Your Network Interface

ip link show

Look for a device that resembles a wired Ethernet interface — often named something like eth0, enpXsY, or enx....

2. Bring the Interface Up

ip link set dev enp4s0 up

Replace enp4s0 with your actual interface name.

3. Assign a Static IP Address

Let’s assume we want:

• IP: 192.168.1.100
• Gateway: 192.168.1.1
• Subnet: 255.255.255.0 or CIDR /24

ip addr add 192.168.1.100/24 dev enp4s0

4. Set the Default Gateway

ip route add default via 192.168.1.1

5. Add DNS Servers

echo 'nameserver 192.168.1.9' > /etc/resolv.conf
echo 'nameserver 8.8.8.8' >> /etc/resolv.conf

6. Test Connectivity

ping -c 3 8.8.8.8
ping -c 3 debian.org

Optional: Reset/Undo

ip addr flush dev enp4s0
ip route flush dev enp4s0

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7. Making the Configuration Persistent with /etc/network/interfaces

If your system uses the classic ifupdown stack (most minimal or older Debian installs do), you can make your settings permanent by editing /etc/network/interfaces like this:

auto enp4s0
iface enp4s0 inet static
  address 192.168.1.100
  netmask 255.255.255.0
  gateway 192.168.1.1
  dns-nameservers 192.168.1.9 8.8.8.8

Then bring it up with:

ifdown enp4s0 || true
ifup enp4s0

This will restore the configuration automatically on every reboot without needing to manually use ip commands again.

Done!

You’ve now gone from a bare interface to a working network connection using only the most essential tools — and optionally made it permanent the Debian way.

Triple "5" Farms – Networking the hard way, because that’s the fun way.