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Traffic leaves on the wrong interface#

Symptom: a device is unreachable, and Route Test shows a different interface than you expect. Almost always seen on a RevPi after a new Octave device is added on eth1.

Example#

The RevPi has direct link routes for 192.168.1.60 and 192.168.1.200. A second battery at 192.168.1.61 was added, but nobody added a route for it. Route Test for 192.168.1.61:

Field Value
Interface eth0
Source 192.168.0.128
Gateway 192.168.0.1 — the site router

The RevPi sends the battery's traffic to the site router, which forwards it towards the internet. The battery never sees it.

Route Test sending an eth1 device out of eth0

Why it happens#

The RevPi picks the most specific matching route:

  1. A /32 route for this exact address — a direct link route on eth1, or a primary host route on eth0 → use it.
  2. Otherwise the longest matching subnet — for example an additional address 192.168.1.16/24 on eth0.
  3. Otherwise the default route, via the site router on eth0.

eth1 is always a /32, so only devices with a direct link route ever leave through eth1.

Fix#

Cause Fix
New Octave device, no direct link route Add it under Secondary interface (eth1) → Direct link routes
Device behind a router, no primary route (Scenario 6) Add a /32 primary route via the router
Typo in a route destination Correct the row
Cables swapped between eth0 and eth1 Swap them back — check with Ethernet Link and the Neighbors table

After the fix, run Route Test again for every device on the site, not only the broken one.