---
title: "No aswer to ARP request"
url: "https://maker.wiznet.io/forum/10881"
markdown_url: "https://maker.wiznet.io/forum/10881/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "barbonist"
created: "2015-03-03T10:03:31+09:00"
last_activity: "2017-05-04T08:34:58+09:00"
language: "en"
views: 664
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# No aswer to ARP request

## Question

Asked by barbonist on 2015-03-03 in Ethernet Chips.

Hi all

I use a W5200 to implement a TCP<–>serial gateway. Normally a PC enstablish a session with my converter , so the conveverter is a server , pc is the client in this case.

I checked the packets on ethernet using comview .
I give W5200 the IP address 10.0.0.212
When I give W5200 a MAC having 0x0b as the first digit , Arp request from PC are not answered from W5100. When I give W5200 a MAC having 0x02 as the first digit , Arp request from PC are answered and communication cannot be enstablished and ping 10.0.0.212 is not sent by PC because no arp entry is present with such address. I checked the arp table on PC and no other unit have 10.0.0.212 is present , therefore the ARP request is issued , with no answered.

Any idea ?
If needed I can attach the log of the answer and no answer situations.

best regards
Stefano

## Replies

### Reply 1 by barbonist, 2015-03-03

Sorry , I wrote erroneusly on my previouse mail:

When I give W5200 a MAC having 0x02 as the first digit , Arp request from PC are answered
and communication can be enstablished and ping 10.0.0.212 sent by PC is answered because arp entry is present with such address.

Communication can’t be enstablished when ARP have no answer, however.

sorry

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Source: https://maker.wiznet.io/forum/10881