[BUG] 0 and 1 Length ACK UDP packets not showing up in log

Question

[BUG] 0 and 1 Length ACK UDP packets not showing up in log

jalius opened this issue 10 months ago · comments

What OS and Version?

Windows 11
V 8.4.3 Binary

Description of issue

The log isn't receiving any 1 length or 0 length UDP packets. These packets are supposed to be responses like ACK, but they don't show up in the log. Wireshark does show the packets.

Dan Nagle · Answer 1 · Sun Sep 24 2023 08:20:11 GMT+0800 (China Standard Time)

This is by design. Packet Sender only shows the data because it lets the OS handle TCP session management.

jalius · Answer 2 · Fri Dec 01 2023 01:12:57 GMT+0800 (China Standard Time)

This is by design. Packet Sender only shows the data because it lets the OS handle TCP session management.

Hi. Do you mind elaborating on this? I'm trying to implement UDP acknowledge but I think I'm missing something fundamental about networking.

Dan Nagle · Answer 3 · Fri Dec 01 2023 01:45:19 GMT+0800 (China Standard Time)

UDP does not use sessions. There are no acknowledgements unless you send that yourself in your code.

Since every UDP packet is complete, Packet Sender does not apply any filtering to UDP.

Here is a screenshot of a zero-data packet captured by Packet Sender:

You may want to set up a loopback test using 2 Packet Senders to help your understanding of what is happening. Take a look at this screenshot as a guide on how you can set that up: #172 (comment) . For your test, use "UDP" instead of TCP.