---
title: "ARP - problem in some network"
url: "https://maker.wiznet.io/forum/11376"
markdown_url: "https://maker.wiznet.io/forum/11376/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "semiart"
created: "2015-10-14T14:16:19+09:00"
last_activity: "2017-05-04T08:37:10+09:00"
language: "en"
views: 670
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# ARP - problem in some network

## Question

Asked by semiart on 2015-10-14 in Ethernet Chips.

Hello, I have problem with connectivyty in one network.
I use many devices with W5500, but in one company network can not connect- ARP ping is not possible from any PC.
If I put my new device with W5500, the switch don’t make APR table a I cant ping this device.
But if I put to my device MAC adress from any anothoer device (from PC explample) it’s wotk 100% good. ARP ping work in second.
Switch block (filter) MAC? NO! if I put new PC to switch it’s work and ping to PC no problem.

Any idea? where problem is?

## Replies

### Reply 1 by lawrence, 2015-10-16

Hello, semiart

Basically, W5500 has no MAC address.

You need to put available MAC address in W5500 for network.

Thank you,

Lawrence

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Source: https://maker.wiznet.io/forum/11376