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Version: scarthgap_2-x

Configuring Ethernet Connectivity

Overview​

This guide explains how to configure and verify a wired Ethernet connection on a device running Clea OS.
Ethernet interfaces are typically recognized automatically by the system, but in some situations, manual configuration may be required.
The following steps describe how to identify the interface, configure IP settings, and confirm network connectivity using standard Linux commands.

Requirements​

Before configuring Ethernet, verify the following:

  • The device is equipped with an Ethernet port or interface (for example, eth0).
  • The Ethernet cable is connected to a valid network switch or router.
  • The corresponding driver is loaded and visible through ip link show.
note

All commands in this guide are executed on the target device, indicated by the # prompt.
Do not copy and paste the # to execute commmands.

1. Identify the Ethernet Interface​

List the available network interfaces using:

# ip link show

You should see an entry similar to the following:

2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether 00:11:22:33:44:55 brd ff:ff:ff:ff:ff:ff

The interface name (eth0, enp1s0, etc.) may vary depending on the hardware and kernel version.
Use this name in the following commands.

2. Enable the Interface​

If the interface is listed as DOWN, enable it with:

# ip link set eth0 up

You can verify the interface state again:

# ip link show eth0

The interface should now show state UP.

3. Obtain an IP Address Automatically (DHCP)​

To request an IP address from a DHCP server, use the udhcpc command:

# udhcpc -i eth0

If successful, the terminal output should include messages indicating the lease of an IP address.
You can confirm by checking the interface configuration:

# ip addr show eth0

4. Assign a Static IP Address (Optional)​

If you need to configure a static IP address instead of using DHCP, run:

# ip addr add 192.168.1.100/24 dev eth0
# ip link set eth0 up

Replace 192.168.1.100/24 with the desired IP address and subnet mask.
You may also set a default gateway:

# ip route add default via 192.168.1.1

To make sure the routing configuration is active, check with:

# ip route show

5. Verify Network Connectivity​

Test basic connectivity within the local network:

# ping -c 4 192.168.1.1

If the gateway responds, test external connectivity (if Internet access is available):

# ping -c 4 8.8.8.8

Finally, check DNS resolution by pinging a domain name:

# ping -c 4 www.google.com

If all tests are successful, the Ethernet connection is configured and functional.

Troubleshooting​

If the Ethernet connection does not work as expected, perform the following checks.

Check Interface Status​

Confirm that the Ethernet link is detected:

# ethtool eth0

Look for the line:

Link detected: yes

If the link is no, ensure that the Ethernet cable and network port are functioning correctly.

Check Driver and Module​

Verify that the appropriate driver is loaded:

# dmesg | grep eth

If the driver is missing or not recognized, refer to the Clea OS hardware compatibility list or kernel configuration documentation.

Restart the Network Stack​

You can reset the interface by bringing it down and up again:

# ip link set eth0 down
# ip link set eth0 up

Then request a new IP address:

# udhcpc -i eth0

Tips for Persistent Configuration​

tip

To make the Ethernet configuration persistent across reboots:

  1. For DHCP: Create a simple startup script that runs udhcpc -i eth0 automatically.
  2. For static IP: Add your configuration to /etc/network/interfaces or a dedicated systemd network unit (for example, /etc/systemd/network/eth0.network).
  3. Confirm that no other network manager is controlling the same interface.

Example of a simple static configuration in /etc/network/interfaces:

auto eth0
iface eth0 inet static
    address 192.168.1.100
    netmask 255.255.255.0
    gateway 192.168.1.1

Summary​

You have configured Ethernet connectivity on a Clea OS device using standard Linux networking tools.
The basic workflow includes identifying the interface, enabling it, assigning an IP address, and verifying connectivity.
You can use DHCP for automatic addressing or configure a static IP for fixed network environments.

By following these steps, your Clea OS device can maintain stable Ethernet communication, suitable for both development and production deployments.