# FreeRTOS+TCP with STM32H7 - where should I define ETH\_RX\_BUF\_SIZE and TX

**URL:** <https://forums.freertos.org/t/freertos-tcp-with-stm32h7-where-should-i-define-eth-rx-buf-size-and-tx/11191>\
**Category:** ST\
**Created:** [November 23, 2020, 9:27am UTC](https://forums.freertos.org/t/freertos-tcp-with-stm32h7-where-should-i-define-eth-rx-buf-size-and-tx/11191 "2020-11-23T09:27:57Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![EyalG](https://avatars.discourse-cdn.com/v4/letter/e/b782af/32.png) [@EyalG](https://forums.freertos.org/u/EyalG)\
**Post date:** [November 23, 2020, 9:27am UTC](https://forums.freertos.org/t/freertos-tcp-with-stm32h7-where-should-i-define-eth-rx-buf-size-and-tx/11191/1 "2020-11-23T09:27:57Z")

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I’m porting the AFR 202011 to my H743 based board and I encounter a build issue with NetworkInterface.c under freertos\_plus\_tcp  
The ETH\_RX\_BUF\_SIZE and ETH\_TX\_BUF\_SIZE are not defined and I can see that in the F4 implementation those defines are located in the stm32f4xx\_hal\_conf.h but this is not the case for the H7.  
Can someone please advise on that?  
Thanks

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**Author:** ![rtel](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/rtel/32/31_2.png) [@rtel](https://forums.freertos.org/u/rtel)\
**Post date:** [November 23, 2020, 3:46pm UTC](https://forums.freertos.org/t/freertos-tcp-with-stm32h7-where-should-i-define-eth-rx-buf-size-and-tx/11191/2 "2020-11-23T15:46:58Z")

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Just from the name, stm32f4xx\_hal\_conf.h looks like it is a configuration file - so can you just add them to that?

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**Author:** ![EyalG](https://avatars.discourse-cdn.com/v4/letter/e/b782af/32.png) [@EyalG](https://forums.freertos.org/u/EyalG)\
**Post date:** [November 23, 2020, 3:59pm UTC](https://forums.freertos.org/t/freertos-tcp-with-stm32h7-where-should-i-define-eth-rx-buf-size-and-tx/11191/3 "2020-11-23T15:59:15Z")

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Thank you for getting back to me on that.  
First, I indeed added it to this file and so far (I’m still trying to get the project compiled) it is passed the compile stage.  
The reason I raised this question is because the readme.txt in the STM32Fxx directory of the NetworkInterface refer specifically to those defines and to where they should be located while the readme.md in the STM32Hxx does not mention them at all and this confused me.  
Thanks!