How to use the command 'airport' (with examples)

The airport command is a wireless network configuration utility used primarily on macOS systems. It provides detailed insights into the status of your wireless connections, enables network scanning, allows for disassociation from networks, and even has the capability to sniff wireless traffic on different channels. It is a powerful command-line tool intended for users who need to manage and troubleshoot wireless connections efficiently. This tool is very useful for network administrators and advanced users who are comfortable with using terminal commands to control various aspects of their wireless networking devices.

Use case 1: Show current wireless status information

Code:

airport --getinfo

Motivation:

Checking your current wireless status information can be crucial for diagnosing connectivity issues, ensuring network security, or simply verifying your connection details. This command provides a snapshot of the current wireless connection, including information such as the SSID, signal strength, and data rate, which can be particularly useful when optimizing your wireless setup or debugging connection problems.

Explanation:

• airport: The base command that invokes the wireless configuration utility.
• --getinfo: A flag used to request the current wireless network status information. It retrieves details of the active Wi-Fi connection, providing essential data for any network-related analysis or troubleshooting.

Example Output:

     agrCtlRSSI: -60
     agrExtRSSI: 0
    agrCtlNoise: -92
    agrExtNoise: 0
          state: running
        op mode: station 
     lastTxRate: 878
        maxRate: 1300
lastAssocStatus: 0
    802.11 auth: open
      link auth: wpa2-psk
          BSSID: xx:xx:xx:xx:xx:xx
           SSID: MyNetwork
            MCS: 9
        channel: 44,80

Use case 2: Sniff wireless traffic on channel 1

Code:

airport sniff 1

Motivation:

Network sniffing is an essential process in network diagnostics and security assessment. Using the airport command to sniff traffic on a specific channel allows you to capture and analyze wireless packets transmitted over that channel. This can help diagnose interference issues, understand network traffic patterns, or identify unauthorized access attempts. Channel 1 is a common starting point since it is one of the default channels used by many routers.

Explanation:

• airport: The command line interface for interacting with the wireless card on macOS.
• sniff: Invokes the listening mode to capture packets on a specified channel.
• 1: The specific channel number to target for sniffing. Sniffing on channel 1 allows you to capture traffic that is being communicated over this particular frequency band.

Example Output:

While there’s no direct terminal output, this command typically initiates a packet capture file that can be further analyzed using network analysis tools like Wireshark.

Use case 3: Scan for available wireless networks

Code:

airport --scan

Motivation:

Scanning for available wireless networks is crucial when you need to connect to a new network or want to assess the wireless environment, including identifying network interference or determining network coverage. This command will list all detectable SSIDs along with their channel, RSSI (signal strength), security type, and other relevant details that help in selecting the most appropriate network to connect to.

Explanation:

• airport: The utility used to manage Wi-Fi connections.
• --scan: This flag performs a scan of the surrounding area to list available wireless networks. The scan reveals all nearby networks, providing information that is essential for network selection and troubleshooting.

Example Output:

                            SSID BSSID              RSSI CHANNEL HT CC SECURITY (auth/unicast/group)
                       MyNetwork 00:11:22:33:44:55 -45  1       Y  -- WPA2(PSK/AES/AES)
              AnotherNetwork     aa:bb:cc:dd:ee:ff -78  6       Y  -- WPA2(PSK/AES/AES)

Use case 4: Disassociate from the current airport network

Code:

sudo airport --disassociate

Motivation:

Disassociating from a network is necessary when you want to forcibly disconnect from the current wireless network without connecting to another one immediately. This can be useful for troubleshooting, controlling which network is used if multiple are detected, or maintaining security and privacy by ensuring no unintentional data transmission over Wi-Fi. Using sudo implies the need for administrative privileges, highlighting the control and potential impact of this command.

Explanation:

• sudo: The prefix used to execute commands with superuser (administrator) privileges, necessary here due to the command’s capability to alter critical network settings.
• airport: The wireless configuration utility being invoked.
• --disassociate: The specific command flag that initiates disconnection from the current wireless network, effectively stopping any ongoing wireless communication until a new connection is made.

Example Output:

There will be no direct output to the terminal, but the system will silently disassociate from the current network. You can verify this by using the airport --getinfo command to show that there is no active connection.

Conclusion:

The airport command line tool is an indispensable utility for macOS users, especially those with technical expertise in network management or those overseeing network environments. Each use case of the airport command serves a distinct purpose, allowing users to gather critical connectivity information, perform network reconnaissance, or manage network connections diligently. Whether you are diagnosing connection issues, capturing network traffic for analysis, or scanning for available networks, using airport equips your terminal with advanced wireless network management capabilities.