---
title: "W5500 works on some routers but not others"
url: "https://maker.wiznet.io/forum/15265"
markdown_url: "https://maker.wiznet.io/forum/15265/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "Philm001"
created: "2024-08-26T00:19:02+09:00"
last_activity: "2024-08-26T06:59:02+09:00"
language: "en"
views: 17
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# W5500 works on some routers but not others

## Question

Asked by Philm001 on 2024-08-26 in Ethernet Chips.

Hello all,

I am having an interesting issue with the W5500 chip. I have it connected to an ESP32 and coded over Arduino. I am using the Arduino Ethernet Shield library. In my code base, I have a functionality where I can use the W5500 chip to perform OTA updates to the ESP32. However, when running the code, I found a “bug” that I need help to understand.

1. On certain hardware (routers and/or switches) when I run the OTA routine, the output suddenly freezes and the hardware/firmware is unable to download the new firmware. This happens even if the chip is setup for static or DHCP

2. When I connect the hardware to one of my main routers, everything works fine as it is suppose to be.

Overall, I don’t think that I have a coding issue but rather some sort of network issue. However, I am not sure if the issue lies on my network hardware or if there is something on the chip that prevents it from operating/communicating with other routers/switches.

I am not sure where exactly to start debugging. If there are certain routers I should avoid while using the W5500 then it would be good to know that. Any assistance would be appreciated.

## Replies

### Reply 1 by Eugeny, 2024-08-26

I’d suggest start with the roots - looking at the network traffic using Wireshark to identify what happens when communication freezes. Then, when you have this info, you try to understand why it happens - from both sides - considering the appropriate RFC. When you found out where process is broken, you raise the bug or try to fix the way you (or we all) can modifying software under your control.

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Source: https://maker.wiznet.io/forum/15265