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Link down or no DHCP address#

Ethernet Link shows no link on eth0 or eth1, or the Connectivity card on the Configuration page shows the interface link as unreachable.

This is always physical:

  1. Is the cable in the right port? On a RevPi, eth0 is site and eth1 is Octave.
  2. Are the link lights on, at the device and at the switch?
  3. Try another cable and another switch port.
  4. Is the switch or device on the other end powered?

10 Mb/s or half duplex instead of 100/1000 full duplex → replace the cable, or ask the site to set the switch port to auto-negotiation.

Symptom B — eth0 has a 169.254.x.x address#

An address starting with 169.254. is a link-local address. The port has link, but no DHCP server answered and no previous lease was available. The device keeps retrying and switches back automatically once DHCP answers — see DHCP recovery.

Check How
Does the site actually use DHCP? Ask the site. If not → Scenario 2 — Static IP.
Is the cable in a port in the right network / VLAN? Ask the site which switch port to use.
Does the DHCP server only serve known devices (MAC filtering)? Give the site the MAC of eth0 from Network Overview.
Does a DHCP offer arrive at all? Press Test on the Configuration page (DHCP mode): DHCP offer received shows the server and the offered values.

To reach a device in this state from your laptop, give the laptop a 169.254.x.x address too and browse to octave<serial>.local.

Symptom C — wrong DHCP server#

eth0 has an address, but in an unexpected range — for example from a 4G router or a forgotten test router on the same LAN. The live view on the Configuration page shows the DHCP server the lease came from.

Fix: remove the second DHCP server. If the site can't do that right away:

  1. Open Primary interface (eth0) – advanced → DHCP server blacklist.
  2. Tick Enable DHCP server blacklist and add the unwanted server's IP.
  3. Test — the DHCP offer should now come from the right server — then Apply.

DHCP server blacklist

Symptom D — IPv6 problems#

Some sites hand out IPv6 but don't actually route it, which slows or breaks cloud connections. Tick Disable IPv6 on eth0 in the advanced section, then Test and Apply.