---
title: "How are leading zeros in an IP address interpreted?"
url: "https://maker.wiznet.io/forum/15200"
markdown_url: "https://maker.wiznet.io/forum/15200/md"
type: "Forum topic"
category: "Wireless"
author: "Haruki"
created: "2024-04-16T22:12:10+09:00"
last_activity: "2024-04-17T01:36:47+09:00"
language: "en"
views: 78
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# How are leading zeros in an IP address interpreted?

## Question

Asked by Haruki on 2024-04-16 in Wireless.

I have a question about how the leading zeros in an IP address are interpreted. In the following examples,

```
AT+CIPSTA_CUR="192.168.1.99"
// vs
AT+CIPSTA_CUR="192.168.001.099"
```

```
AT+CIPSTART="TCP","192.168.1.99",5000
// vs
AT+CIPSTART="TCP","192.168.001.099",5000
```

would these commands be processed identically? Do leading zeros cause the number to be interpreted as octal or are leading zeros ignored? I could not find any documentation that mentions this, and cannot currently test this for myself.
Thank you in advance.

## Replies

### Reply 1 by Aimee0, 2024-04-17

I confirmed through testing that leading zeros cause the number to be interpreted as octal. We recommend you to use it as follows.
AT+CIPSTART=“TCP”,“192.168.1.99”,5000

---

Source: https://maker.wiznet.io/forum/15200