DHCP Vendor Class Identifier: MSFT 5.0 and Beyond

Understanding Device Types in DHCP Requests

In DHCP (Dynamic Host Configuration Protocol), the Vendor Class Identifier (VCI) in the DHCP request message helps identify the type of device requesting an IP address. Two common VCIs are "MSFT 5.0" and "dhcpcd-5.5.6", indicating a Windows computer and an Android device, respectively.

Updated VCI for Windows Devices

The traditional VCI for Windows devices, "MSFT 5.0," has been updated to "MSFT 5.0" for some devices. This change allows for more accurate device identification and ensures that Windows devices receive appropriate DHCP configuration.

DHCP Discovery Process

When a DHCPv4 client device joins a network, it sends a DHCPDISCOVER message to search for a DHCP server. This message includes various options, including the VCI. The DHCP server then responds with a DHCPOFFER message, providing an IP address and other configuration parameters to the client device.

Example: MSFT 5.0 for Light Cat Devices

The "light cat" is a hypothetical device that uses the MSFT 5.0 VCI. This indicates that the device is a Windows-based device, and the DHCP server would configure it accordingly. The following image shows an example of a light cat device:

By understanding the VCI mechanism in DHCP requests, network administrators can ensure that devices receive accurate IP address configurations and are integrated properly into the network.