---
title: "the tftp client cannot send packets properly"
url: "https://maker.wiznet.io/forum/14708"
markdown_url: "https://maker.wiznet.io/forum/14708/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "Gaplin1"
created: "2022-11-15T03:37:54+09:00"
last_activity: "2022-12-19T04:48:50+09:00"
language: "en"
views: 291
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# the tftp client cannot send packets properly

## Question

Asked by Gaplin1 on 2022-11-15 in Ethernet Chips.

dear all:
hello, I’m sorry to take up your time
I am using the w5100s chip and after configuring the network, create one of the sockets as the tftp client. Sometimes I can use it to get files from the server normally. However, if the device is not powered on for a long time (one or two days), files may fail to be obtained occasionally. In this case, I used the packet capture software and found that no request packet was sent at all. Print to find that the snd len returned by sendto is negative. I wonder why this is happening and how to solve it.
And the amazing thing is that when I restart the upper computer this goes away.
Gap

## Replies

### Reply 1 by Gaplin1, 2022-11-15

[![图片1](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/0/01a5b295e9542175372364c99f464f5ab5282035.png) 图片11378×572 28.7 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/0/01a5b295e9542175372364c99f464f5ab5282035.png)

send error:

[![image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/e/e5fb6163e46067896f5d1149c901aa4909be5064.png) image1133×670 46.6 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/e/e5fb6163e46067896f5d1149c901aa4909be5064.png)

After the restart:

[![image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/3/35553831477019e75fd05149da58b5dcec93e631.png) image1133×670 35.6 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/3/35553831477019e75fd05149da58b5dcec93e631.png)

---

Source: https://maker.wiznet.io/forum/14708