---
title: "mac address setting"
url: "https://maker.wiznet.io/forum/14939"
markdown_url: "https://maker.wiznet.io/forum/14939/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "Assaf Dahary"
created: "2023-06-15T06:25:15+09:00"
last_activity: "2023-06-15T06:25:15+09:00"
language: "en"
views: 213
replies: 0
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# mac address setting

## Question

Asked by Assaf Dahary on 2023-06-15 in Ethernet Chips.

I have tens (60) of w5100s hats (which I plan to use for PICOs) connected to a switch.
I configured each with its IP but then figured out that all of them have the same MAC address, which causes many TCP retransmission.

How can I set each w5100s module with its unique MAC address?

I found this python class but failed to use it.
@mac_address.setter
def mac_address(self, address):
“”“Sets the hardware MAC address.
:param tuple address: Hardware MAC address.
“””
self.write(REG_SHAR, 0x04, address)

Regards

Assaf.

---

Source: https://maker.wiznet.io/forum/14939