DHCP vendor identifier options

Enhanced support for non-Microsoft devices and DHCPv6

DHCP Client Side Features in the Windows 10 April 2018 Update

Some devices will now show up as MSFT 50 XBOX New DHCP Client-side features in the Windows 10 April 2018 Update. MSFT 5 0 is a windows computer dhcpcd-5 5 6 is an android device Its vendor class indentifier in the dhcp request. The DHCPv4 client joins the network and sends a DHCPDISCOVER message that includes a Vendor Class Identifier Option with for example the value MSFT 50. In this article Ill explain how this mechanism works and how you can send Microsoft Windows specific DHCP options from a non-Microsoft DHCP server like a Linux or Lucent. When looking at the DHCP process between devices and my Wi-Fi router DHCP server with Wireshark I noticed that most devices provide a Vendor Class Identifier or Option 60.

After the initial DHCPDISCOVER packet is sent the device receives a DHCPOFFER packet with IP address and other network configuration options. Now the device sends a DHCPREQUEST packet to accept the offered address. Vendor specific options can be included in the DHCPOFFER and DHCPREQUEST packets. If the DHCP server supports the vendor class identifier of the DHCP client it will include the associated options. These options can then be used to provide vendor specific configuration to the client.

Microsoft has added support for new DHCP vendor options in the Windows 10 April 2018 Update. These new options allow non-Microsoft DHCP servers to provide Microsoft Windows specific configuration to clients. This is useful for environments where a non-Microsoft DHCP server is being used to provide DHCP services to Windows clients. The new options are as follows:

• **Option 121: Microsoft DHCP Server Identifier** - This option identifies the Microsoft DHCP server. The value of this option is a DHCP server ID that is assigned by Microsoft.
• **Option 122: Microsoft DHCP Lease Time** - This option specifies the lease time for the DHCP lease. The value of this option is a lease time in seconds.
• **Option 123: Microsoft DHCP Renew Time** - This option specifies the renew time for the DHCP lease. The value of this option is a renew time in seconds.
• **Option 124: Microsoft DHCP Rebind Time** - This option specifies the rebind time for the DHCP lease. The value of this option is a rebind time in seconds.
• **Option 125: Microsoft DHCP T1 Time** - This option specifies the T1 time for the DHCP lease. The value of this option is a T1 time in seconds.
• **Option 126: Microsoft DHCP T2 Time** - This option specifies the T2 time for the DHCP lease. The value of this option is a T2 time in seconds.

These new options can be used to provide more control over the DHCP lease process for Windows clients. They can also be used to troubleshoot DHCP issues in environments where a non-Microsoft DHCP server is being used.

In addition to these new options Microsoft has also added support for DHCPv6 in the Windows 10 April 2018 Update. This means that Windows clients can now obtain IPv6 addresses from DHCP servers. DHCPv6 is the next generation of DHCP and is designed to support the larger address space of IPv6. It also includes a number of new features that make it more efficient and secure than DHCPv4.

The addition of DHCPv6 support in Windows 10 is a significant step forward. It will allow Windows clients to take advantage of the benefits of IPv6 and will help to ensure that they are able to connect to the internet in the future.