---
title: "W5500 communication failure"
url: "https://maker.wiznet.io/forum/16125"
markdown_url: "https://maker.wiznet.io/forum/16125/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "Albin77777"
created: "2026-07-25T13:49:59+09:00"
last_activity: "2026-07-27T09:11:10+09:00"
language: "en"
views: 5
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# W5500 communication failure

## Question

Asked by Albin77777 on 2026-07-25 in Ethernet Chips.

Hello,

I connected W5500 with STM32F401, and hang up with issues. I am using http server.

**Issue**: LAN cable to W5500 communication failure. PC is sending handshake packets but W5500 is not responding

Observations

**1.) W5500 with STM32 is working fine SPI is working fine(read the version register it is 04)  Read the IP, subnet, gateway register:working fine Read the socket register: it is open--listen2) green led is working(link led), orange led(not all the times  3.) arp -a lists the device ip and Mac4.) Wire shark shows retransmission, when accessing via webpage(192.168.1.10:50005.) Windows firewall is turned off5) ethernet driver in pc is ok **

## Replies

### Reply 1 by Aimee0, 2026-07-27

Is the issue that the web server is not opening properly?

If so, could you please check whether the same issue occurs when using different web browsers, such as Google Chrome and Microsoft Edge?

Also, please refer to the HTTP Server example below and compare your configuration and implementation with the example.

<https://github.com/Wiznet/ioLibrary_Driver/tree/master/Internet/httpServer>

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Source: https://maker.wiznet.io/forum/16125