FreeRTOS+TCP and PHY + Switch

Sounds like you’re hitting a similar issue to what I had in xPhyCheckLinkStatus Triggering Re-Autonegotiations When Not All Ports Are Connected

The default logic for the phyHandling is to assume all network ports are connected & the xPhyCheckLinkStatus enforces that. If you’re running a switch with multiple ports (not all of them connected) you’ll need to modify that code in your checkout.