Network / SSH Troubleshooting

Cannot reach the board over the network

Connect via serial console and run:

ip addr show

Look for an inet address on eth0 or end0. If no IP is assigned, see the DHCP section below.

The host and board must be on the same subnet. Example:

From the host:

ping <board-ip>

If ping fails but the IP is correct, check for a firewall on the host:

sudo iptables -L INPUT

In a lab environment, avoid DHCP uncertainty by setting a fixed IP on the board.

No IP assigned by DHCP

ip link show eth0

The output should include UP and LOWER_UP. If it shows NO-CARRIER:

systemctl status systemd-networkd
# or
systemctl status dhclient

dhclient eth0
# or with systemd-networkd:
networkctl renew eth0

If no address is assigned after ~10 seconds, there is no DHCP server reachable on that network segment.

SSH: connection refused

systemctl status sshd

Start it if needed:

systemctl start sshd
systemctl enable sshd   # persist across reboots

Add to your Yocto configuration and rebuild:

# local.conf or image recipe
IMAGE_FEATURES += "ssh-server-openssh"

Check which port it is listening on:

ss -tlnp | grep ssh

Confirm there is no host-side firewall blocking port 22:

sudo iptables -L INPUT -n

SSH connection times out or drops

Add to ~/.ssh/config on the host:

Host <board-ip>
    ServerAliveInterval 30
    ServerAliveCountMax 3

If DHCP is in use, the board IP may change after a reboot. Set a fixed IP or configure a DHCP reservation on your router.