### Description of defect Following build error appears when compiling blinky example for the following target: > ./mbed-os/features/netsocket/emac-drivers/TARGET_STM/stm32xx_emac.cpp", line 89: Error: #20: identifier "ETH_RX_BUFFER_SIZE" is undefined #### Target(s) affected by this defect ? NUCLEO_H743ZI2 #### Toolchain(s) (name and version) displaying this defect ? Armc5 #### What version of Mbed-os are you using (tag or sha) ? mbed-os-5.14.2 #### What version(s) of tools are you using. List all that apply (E.g. mbed-cli) latest #### How is this defect reproduced ? `mbed compile` of mbed os blinky