---
title: "DNS connection not working in W7500S2E-R1 module"
url: "https://maker.wiznet.io/forum/14021"
markdown_url: "https://maker.wiznet.io/forum/14021/md"
type: "Forum topic"
category: "Serial-to-Ethernet & ConfigTool"
author: "Praveena"
created: "2020-09-28T11:45:14+09:00"
last_activity: "2020-09-28T11:45:14+09:00"
language: "en"
views: 479
replies: 0
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# DNS connection not working in W7500S2E-R1 module

## Question

Asked by Praveena on 2020-09-28 in Serial-to-Ethernet & ConfigTool.

Hi,

I am using the wiznet W7500S2E-R1 module. I found an extreme case in wiznet, when module is been powered on after a long gap (let say 1 day), factory reset and try to connect with DNS enabled at the first attempt to make a connection, the connection will be unsuccessful.

After factory reset, I input the following AT commands,

AT+C1_OP=1
AT+IP_MODE=1
AT+DNSEN=1
[AT+DOMAIN=mi-office.com](http://AT+DOMAIN=mi-office.com)
AT+EXIT

After AT+EXIT, i expect the module attempt to connect to the domain - [mi-office.com](http://mi-office.com), which is not happening. I attached the screenshot & Wireshark log here.

[![image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/0/00883c7d376c1070d386bc1ab3f676ea8f1924fb.png) image1920×1040 18.8 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/0/00883c7d376c1070d386bc1ab3f676ea8f1924fb.png)

[Windows-WizDNS-1st-Attempt-AfterFactoryReset-1.zip](https://maker.wiznet.io/forum/legacyFile.asp?path=n7hoC26VbxZWHsFVNOjR0aP57ug.zip) (653 Bytes)

But, later when i reset the module and again going to data mode is making a successful connection. Attached the screenshot & Wireshark log here.

[![image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/9/9bcd9972c1cc37d309110c1096c207e6bc1a678f.png) image1920×1040 20.4 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/9/9bcd9972c1cc37d309110c1096c207e6bc1a678f.png)

[Windows-WizDNS-2nd-Attempt-AfterFactoryReset-2 .zip](https://maker.wiznet.io/forum/legacyFile.asp?path=8bfqxnUIOlfGhjbqMjWVRJdv8gx.zip) (4.2 KB)

Also whenever I try to use the DNS feature (AT+DNSEN=1), more often the connections are failing. Whereas when I connect the IP without using DNS enabled, I never get a failure in connections.

Thanks,
Praveena

---

Source: https://maker.wiznet.io/forum/14021