2.2.2.3 Vendor-Specific Option Code 0x03 - Microsoft Default Router Metric Base Option

This option is sent by the DHCPv4 server to the DHCPv4 client in a DHCPOFFER or a DHCPACK message. It has no effect on subsequent options in that message or on the DHCPREQUEST message sent by the client to the server.

This option is used to set the default route metric (as specified in [RFC1812] section 5.2.4.3) for all automatically computed network routes for the network interface on which the DHCPv4 message was received. DHCPv4 clients SHOULD<5> support this option.


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Vendor-specific Option Code

Vendor-specific Option Length

Vendor-specific Option Data

...

Vendor-specific Option Code (1 byte): This MUST be 0x03.

Vendor-specific Option Length (1 byte): This MUST be 0x04.

Vendor-specific Option Data (4 bytes): If zero, clients are to compute a route metric based on link speed. Otherwise, this value overrides the automatically calculated metric for the default route for that network interface.

The automatically calculated metric for the default route for DHCPv4 client computers SHOULD<6> be one of the following values.

Value

Meaning

0x0000000A

Greater than 200 Mbps.

0x00000014

Greater than 80 Mbps, and less than or equal to 200 Mbps.

0x00000019

Greater than 20 Mbps, and less than or equal to 80 Mbps.

0x0000001E

Greater than 4 Mbps, and less than or equal to 20 Mbps.

0x00000028

Greater than 500 Kbps, and less than or equal to 4 Mbps.

0x00000032

Less than or equal to 500 Kbps.