Hi Rudi Thanks for replying. Sorry my bad I forgot to mention that the router in between the route to the master is actually ESP32 too. I don't know if there is any firewall rules on ESP32. The ttl read from the ESP32 making the modbus response to the master is 255. Also the message that gets return...

Hi I am using ESP32 with modbus tcp to connect from ESP32 as a slave to a master running on a device behind a router. I am getting an error on the router with line icmp time exceeded when ESP32 is replying to the master. The packet routes just fine to the ESP32 and to the master but it gets dropped ...