---
title: Recording a Wi-Fi Packet Trace
framework: network
role: article
role_heading: Article
path: network/recording-a-wi-fi-packet-trace
---

# Recording a Wi-Fi Packet Trace

Record traces of Wi-Fi traffic and traffic management.

## Overview

Overview When working with Wi-Fi, your best option for recording a packet trace depends on whether you’re interested in the network traffic itself, or in the details of how the Wi-Fi network manages traffic. Record a High-Level Packet Trace of Wi-Fi Traffic If you’re primarily interested in the traffic going over the Wi-Fi — that is, you would like to ignore all the low-level details of Wi-Fi and treat the Wi-Fi network like an Ethernet network without all those pesky wires — use one of the following high-level approaches: If possible, run the packet trace on one of the machines involved in the communication — including using RVI to record an iOS packet trace. That’s the easiest solution. See Recording a Packet Trace for instructions. If your Wi-Fi access point supports bridge mode (notably, all Apple base stations do), you can bridge the Wi-Fi network on to an Ethernet network and then use standard Ethernet techniques to capture a packet trace. You won’t be able to see Wi-Fi to Wi-Fi traffic, but in many situations that’s not a problem. If you enable Internet Sharing on your Mac, and have your Wi-Fi clients join the shared network, you can run your packet trace program on the Mac and see all the Wi-Fi traffic. If you target the Mac’s Wi-Fi interface, you will see all traffic, including Wi-Fi to Wi-Fi traffic. If you target the Mac’s Ethernet interface, you will only see traffic entering or leaving the Wi-Fi network. Record Low-Level Details of Wi-Fi Traffic Management If you are interested in the low-level details of how the Wi-Fi network manages traffic, record a low-level Wi-Fi packet trace. To do this: Choose a Mac on which to record your trace. That Mac cannot use the Wi-Fi interface for normal network traffic while recording the trace. Configure your access point to use a fixed channel. When recording a packet trace, you must specify the channel to record, and having the access point choose its channel automatically makes that harder. Either temporarily turn off the Wi-Fi password on your network or use a separate test network that has no password. If the Wi-Fi network has a password, Wi-Fi encryption makes it harder to examine the trace. Open the Wireless Diagnostics app (you can find this in /System/Library/CoreServices/Applications/). Choose Window > Sniffer. In the Sniffer window, select the channel number and width you want to record and click Start. Click Stop when you’re done. In the Finder, navigate to /var/tmp/ and look for the resulting .pcap file.

## See Also

### Working with Packet Traces

- [Troubleshooting Packet Traces](network/troubleshooting-packet-traces.md)
- [Submitting a Packet Trace to Apple](network/submitting-a-packet-trace-to-apple.md)