DHCP Vendor Class Identifier: MSFT 5.0 and Beyond

New Identifier for Windows and Android Devices

The DHCP Vendor Class Identifier (VCI) is used by DHCP servers to identify the type of device that is requesting an IP address. Traditionally, Windows devices have used the VCI "MSFT 5.0". However, with the release of Android 5.1.1, a new VCI "dhcpcd-5.5.6" has been introduced for Android devices.

Rationale for the Change

The reason for the change in VCI is to better identify the type of device that is requesting an IP address. This information can be used by DHCP servers to provide more efficient and tailored service to different types of devices.

Impact on DHCP Servers

The change in VCI may require DHCP servers to be updated to support the new identifier. DHCP servers that are not updated may not be able to properly assign IP addresses to Android devices using the "dhcpcd-5.5.6" VCI.

Lightcat and Device Type

In the example provided, the device type is shown as "MSFT 5.0" in the Lightcat interface. This is because Lightcat uses the traditional VCI "MSFT 5.0" to identify Windows devices, even though the device may be running a newer version of Windows that uses the new VCI "MSFT 5.5."

IP Assignment Process

The process of assigning IP addresses to devices on a network is as follows:

1. The device sends a DHCP Request message to the DHCP server.
2. The DHCP server responds with a DHCP Reply message that contains the IP address, subnet mask, and other configuration information.
3. The device uses the information in the DHCP Reply message to configure its network settings.

Troubleshooting

If you are having trouble assigning IP addresses to your devices, you can check the following:

• Ensure that your DHCP server is up and running.
• Ensure that your devices are configured to obtain IP addresses automatically.
• Ensure that your DHCP server is configured to support the VCI that your devices are using.