# lwip_tcpecho_multi_ports_rtthread-nano

## Overview

This example shows TCP echo communication on multiple ports on RTThread-Nano.

- PC sends TCP data frames to MCU,  and then MCU sends the data frames back to PC

## Board Settings

- Connect a USB port on PC to the PWR DEBUG port on the development board with a USB Type-C cable
- Connect two Ethernet ports on PC to a RGMII port and a RMII port on the development board with two Ethernet cables

## Project Configurations

- Ethernet Port Settings: Refer to [Ethernet common project settings](../doc/Ethernet_Common_Project_Settings_en.md)
- Ethernet DHCP Configurations
    - the configurations in the `CMakeLists.txt` as follows:
      - sdk_compile_definitions(-DLWIP_DHCP=0): Disable DHCP feature
      - sdk_compile_definitions(-DLWIP_DHCP=1): Enable DHCP feature


## Run Example

- Compiling and Downloading
- Running log is shown in the serial terminal as follows:

  ```console
  This is an ethernet demo: TCP Echo With Multi Ports On RTThread-Nano
  LwIP Version: 2.1.2
  Enet1 Reference Clock: Internal Clock

   \ | /
  - RT -     Thread Operating System
   / | \     3.1.5 build Mar 18 2024
   2006 - 2020 Copyright by rt-thread team
  msh >Enet0 init passed!
  Enet1 init passed!
  ================ Network Interface 1 ================
  Link Status: Down
  ================ Network Interface 1 ================
  Link Status: Up
  Link Speed:  100Mbps
  Link Duplex: Full duplex
  ================ Network Interface 1 ================
  IPv4 Address: 192.168.200.10
  IPv4 Netmask: 255.255.255.0
  IPv4 Gateway: 192.168.200.1
  ================ Network Interface 0 ================
  Link Status: Down
  ================ Network Interface 0 ================
  Link Status: Up
  Link Speed:  1000Mbps
  Link Duplex: Full duplex
  ================ Network Interface 0 ================
  IPv4 Address: 192.168.100.10
  IPv4 Netmask: 255.255.255.0
  IPv4 Gateway: 192.168.100.1
  ```
- Run an Ethernet debugging tool

  - create and set two TCP clients:
    TCP Server 0 IP: 192.168.100.10/Port: 5001
    TCP Server 1 IP: 192.168.200.10/Port: 5002

    **Note: There is a necessary adjustment for Server IP according to the segment of  LAN where PC resides**

  - Connect

  - Enter and send any characters in the edit window(192.168.100.10/5001)

    <img src=../doc/lwip_tcpecho_multi_ports_0_1.png align=left>

  - Watch the characters echoed from MCU window(192.168.100.10/5001)

    <img src=../doc/lwip_tcpecho_multi_ports_0_2.png align=left>

  - Enter and send any characters in the edit window(192.168.200.10/5002)

    <img src=../doc/lwip_tcpecho_multi_ports_1_1.png align=left>

  - Watch the characters echoed from MCU window(192.168.200.10/5002)

    <img src=../doc/lwip_tcpecho_multi_ports_1_2.png align=left>