---
title: "!Ignoring Subnet Mask"
url: "https://maker.wiznet.io/forum/10131"
markdown_url: "https://maker.wiznet.io/forum/10131/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "kevinweiss"
created: "2014-04-10T18:55:41+09:00"
last_activity: "2017-05-04T08:32:23+09:00"
language: "en"
views: 504
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# !Ignoring Subnet Mask

## Question

Asked by kevinweiss on 2014-04-10 in Ethernet Chips.

I have an urgent problem, I am in the middle of testing and have found that the stack ignores the subnet. For example I can still transmit to 192.168.1.1 if my subnet mask is 255.255.0.0 and my ip is 192.168.0.10.

I am using the SW Microchip W5200 stack.

Where is the comparison made and how can I discard if it is in an unacceptable subnet mask.

Thanks,

Kevin

## Replies

### Reply 1 by suhwan, 2014-04-11

Hi,

As you know, if you used SW Microchip W5200 stack,
W5200 can be only used in MAC-PHY mode and can be used Soft TCP/IP stack (Microchip Soft TCP/IP stack).

Therefore, your questions are about Microchip Soft TCP/IP stack V1.4.
I afraid that we can’t support this issue.

Thanks,

---

Source: https://maker.wiznet.io/forum/10131