lwIP Wiki

Giuseppe3092 Giuseppe3092 9 November 2020

Configuring lwIP for sockets on Hercules TMS570LC43x

Hi everybody,

I am trying to configure lwIP library for using sockets on TI Hercules TMS570LC43x hardware.

Every attempt I make I get bunch of errors in compiling and linking. 

What is the right configuration for my application (a simple socket client to communicate over Ethernet)?

Thanks in advance.


Giuseppe Galioto

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Tishyazb Tishyazb 4 August 2020

Queries related to LWIP


I am using the Zedboard. I want to send files or texts from my host PC to zedboard through the ethernet port. I have a standalone BSP and I have included LWIP in it. So in this case I am using raw API. I have developed a file transfer application software like teraterm (which is running on the PC) where I can put the IP address of Zedboard and select a particular port and send the intended file. But anyhow I cannot establish the connection between my PC and zedboard running on LWIP. Can anyone guide me regarding this issue?

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Hawkandspit Hawkandspit 18 December 2019

Link up/down detection

How can I tell whether my network link is up or down so I know when I can use it? Once the link is up, do I call netifapi_dhcp_start to get an address?

The lwIP documentation is skeletal and does not really tell how to use it. I need something more like a user's guide, as well as the reference manual.

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Vampire199669 Vampire199669 15 November 2019



i want to make my STM32 board as client and create GET/POST request to my server running remotely using Ethernet present on the board.

how to http get post request on a running server.

i have got an lwip example which explains the process of making board as a server not a client.

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Dimonira Dimonira 9 September 2019

Strange NETCONN Behavior

There are two FreeRTOS tasks, each of which creates its own NETCONN object. In one task (the first one begins to execute) there are no oddities when creating a NETCONN object. And in the second task there is: the object returned by netconn_new contains the incorrect address of the pcb union - it seems to be back to front.

I went step by step into the netconn_new_with_proto_and_callback function (it is called when netconn_new), the conn object is created absolutely normal in it:

But in the next step, when its address returns to the function call point, the debugger shows the NETCONN object with the incorrect pcb address:

Further, at the very first attempt to use, for example, p UdpConn-> pcb.udp-> loc al_ip, the processor goes into the hardwa…

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Shahrukhkk Shahrukhkk 4 July 2019

LWIP with NS3


I have a question regarding the integration of LWIP with Network simulator 3. If I have to run simulations of LWIP in NS3 (or some other simulator), how can that be possible?



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Ddlawrence Ddlawrence 2 May 2018

lwIP on the Beaglebone UDP problem

Hi all.  I am working on a lwIP port to the Beaglebone Black bare-metal (no OS). 

So far the stack seems to work with the echo server and http server. 

I am working on a UDP server/client now.  I can send a single packet from one 'bone to another. 

I cannot send a series of packets a few seconds apart.  Only the first one gets thru.  Nothing on the IP layer either. 

I must be doing something wrong setting up PBUF or the PCB.

I am running out of options, anyone have an idea?



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Kausiknathan Kausiknathan 18 September 2017

Lwip Stack 2.0.2 Integration with Infineon Aurix TC299 MCAL Source

Hi ,

I have an Infineon Aurix TC299 board with an ethernet interface.

Infineon gave us the MCAL librabry to run the basic ethernet demo application like Ping, RX and TX frames etc etc.

This library demo app intializes the MAC and the PHY at 100MBps.

Issue :

For our application we need the LWIP 2.0.2 stack integarted to this Libraby and ensure we send and receive the packets with TCP header + IP header + MAC header + payload format with the unit on the other side of our ethernet interface.

This is a Non-OS board, so i intergarted the Lwip 2.0.2 stack with the library and made necessary changes as mentioned in the link provided below : http://lwip.wikia.com/wiki/Porting_For_Bare_Metal

We call the Lwip_init and Netif_add functions in the Ethernet Ini…

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Cuc0ach1ng Cuc0ach1ng 22 July 2017

UDP transmit timing query


I am developing a UDP application using lwip on a Zynq FPGA bare metal platform. My application sends Status packets using udp_sendto() to a PC host every 1s when the host is not responding. The packets are observed (on Wireshark) as being sent in the correct sequence and with the corrrect content and length. However, a packet doesn't appear on the network every 1s. 2 packets with same timestamp are sent on each 2s boundary. I believe by observing lwip debug prints that data is sent to the network every 1s but am not sure why the stalling of packets happens. Ay guidance is appreciated

Thank you

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Doriano dotsys Doriano dotsys 12 March 2016

RFC (Request for Comment) implemented in LwIP

I'm using the LwIP ver. 1.3.2 ported by STMicroelectronics for the STM32F207 Microcontroller.

My customers ask if this stack implemented the following RFC:

-   link layer RFC: 826

-   IPv4 network layer RFCs: 791, 894, 1042, 1122

-   transport layer RFCs: 793, 813, 1122, 1191, 1323, 2012, 2581, 2988 There is someone can give a answer? Thanks in advanced.


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Johnwilliamhoffman Johnwilliamhoffman 6 May 2015

Missing ACKs using LWIP 1.3.2

We are using LWIP 1.3.2(as ported by TexasInstruments), IAR compiler targeting a stellaris MCU. The TI implementation uses a timer tick interrupt 100 times/sec to service the LWIP stack. No RTOS involved. Our application code also runs on this same timer tick interrupt so no concurrency issues in play.

We implemented a webservice http client over tcp. Periodically(about 1-2 times per day), we miss ACKs in the application layer. Plain and simple, our tcp_sent callback does not get called. We have timers that expire if the ack is not seen. I have captured the WireShark trace and the ack is being transmitted. For some reason the lwip stack does not inform the application layer. I don’t know if the LWIP stack sees the ack or not.

The odd thi…

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Bellphin Bellphin 5 August 2014

TCP/IP Listen issue


I use EVK1100 in AT32. In this project, we using RTOS+LWIP. 

we have implemented the TCP/IP using default files. what problem we are facing in the

project is that our TCP can listen the sockets only three times thereafter if we try to open the port it won't open. then we have to restart the system.

So We want to know

is any TCP/IP listen limitation in lwip?

if any limitation are there how can we overcome the issue?

Please anybody help for us?

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