---
title: "Issues with W5500 IC in External Network Setup"
url: "https://maker.wiznet.io/forum/15226"
markdown_url: "https://maker.wiznet.io/forum/15226/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "dark0306kr"
created: "2024-05-22T03:36:48+09:00"
last_activity: "2024-06-04T02:28:50+09:00"
language: "en"
views: 143
replies: 8
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# Issues with W5500 IC in External Network Setup

## Question

Asked by dark0306kr on 2024-05-22 in Ethernet Chips.

I have developed a PCB using the W5500 IC and have encountered an issue when connecting to an external network. Below are the details:

1. Our PCB uses the W5500 IC.

2. It works fine in an internal network setup.

- Connection structure:
  → PC (TCP Client) - W5500 (TCP Server): Connection works correctly.

1. It does not work in the external network setup 1.

- Connection structure:
  → PC (TCP Client) - Wireless LAN (Client-router) - W5500 (TCP Server): Connection fails.

- Wireless module: MOXA-AWK-1137C

- Port forwarding is applied.

1. It works in the external network setup 2.

- Connection structure:
  → PC (TCP Client) - Wireless LAN (Client-router) - PC (TCP Server): Connection works correctly.
  (Since this setup works, we believe the wireless LAN settings are correct.)

Additional Information:

1. W5500 settings:

- IP: 192.167.100.133

- Port: 502

- Subnet: 255.255.255.0

- Gateway: 192.167.100.9

- DNS: 0.0.0.0

1. Wireless module settings:

- WAN IP: 192.168.11.25

- Subnet: 255.255.255.0

- Gateway: 192.168.10.1

- LAN IP: 192.167.100. 9

- Subnet: 255.255.255.0

Could you please help us identify why the connection fails in the external network setup 1?
Thank you for your assistance.

## Replies

### Reply 1 by Eugeny, 2024-05-22

PC TCP client settings? PC TCP server settings?
(as they are listed using `ifconfig -a` or `ipconfig /all`)

### Reply 2 by dark0306kr, 2024-05-22 (in reply to reply 1)

Hi Eugeny

## -------------Some of the above contents --------- 4. It works in the external network setup 2. Connection structure: → PC (TCP Client) - Wireless LAN (Client-router) - PC (TCP Server): Connection works correctly.

Please refer to the attached document for details regarding PC TCP client settings and PC TCP server settings.

Thank you once again for your interest and feedback.
[Network connection.pdf](https://maker.wiznet.io/forum/legacyFile.asp?path=htIkA3G6TtlNd0b7Wy77d5knqDK.pdf) (532.3 KB)
Kind regards,

### Reply 3 by Eugeny, 2024-05-22

You are trying to reach from 192.168.11.25 to 192.167.100.133.

dark0306kr:

> 1. Wireless module settings:
>
> - WAN IP: 192.168.11.25

At the same time you say that you assign same IP address to the client PC.

The fact that PC works but W5500 does not means there’s a possibility for connectivity, but PC is much more clever in finding the ways for this connectivity if something is configured incorrectly. You must have some issue with zoning/addressing, or firewall.

### Reply 4 by dark0306kr, 2024-05-27

Thank you for your feedback.

I plan to investigate the cause through MOXA wireless module technical support on Wednesday.
If the issue is not resolved, I will contact you again.

Thank you.

### Reply 5 by dark0306kr, 2024-05-29

Today, I spent about 2 hours working with a MOXA product engineer in Korea to troubleshoot an issue, but we were unable to resolve it.

Do you know how I can contact on-site technical support in Korea?

### Reply 6 by louis, 2024-05-29

안녕하세요.
W5500과 PC 1:1 통신 했을 어떤지 확인 부탁드리겠습니다

추가적으로

1. MOXA가 게이트웨이 역할을 하는 장비인가요?

2. PC에서 Ping 을 보냈을 때 W5500의 응답이 오는 지 확인 부탁드릴 수 있을까요??

감사합니다

### Reply 7 by dark0306kr, 2024-05-29

1. W5500과 PC를 1:1로 연결하면 모든 것이 정상적으로 작동합니다.

2. MOXA 제품이 연결된 조건에서
   W5500 대신 다른 장비를 연결하면 정상적으로 작동합니다. (상기 첨부파일 참고)

이러한 상황이 이해되지 않아서 MOXA측 네트워크 전문가의 도움을 받아서 다양한 시험을 하였지만 문제를 해결하지 못했습니다.

### Reply 8 by dark0306kr, 2024-05-30

귀사에서 제공해주신 기술지원 덕분에 모든 문제를 성공적으로 해결할 수 있었습니다.

특히, 이상준 Director님의 지원에 깊이 감사드립니다.

귀사의 번창을 기원합니다.
다시 한번 깊은 감사의 말씀을 드립니다.

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Source: https://maker.wiznet.io/forum/15226