2.2.3.2.2.2 DNS ADD USER

The DNS ADD USER structure is used by DNS_ADDR DnsAddrUserDword field.

0	1	2	3	4	5	6	7	8	9	1 0	1	2	3	4	5	6	7	8	9	2 0	1	2	3	4	5	6	7	8	9	3 0	1
SockaddrLength
SubnetLength
Flags
Padding (20 bytes)
...
...

SockaddrLength (4 bytes): The length of valid data in the socket address structure present above this field.

SubnetLength (4 bytes): Senders MUST set this to 0x00000000 and receivers MUST ignore this value.

Flags (4 bytes): Clients MUST set to 0x00000000. Senders will use this field to indicate the results of IP validation for this IP address, where it has a format as follows (in host byte order):

0	1	2	3	4	5	6	7	8	9	1 0	1	2	3	4	5	6	7	8	9	2 0	1	2	3	4	5	6	7	8	9	3 0	1
T	Zero							RTT												validationStatus

T (1 bit): If set, DNS over UDP is available from the remote DNS server but DNS over TCP is not available.

Zero (7 bits): Reserved. Senders MUST set these bits to zero and receivers MUST ignore them.

RTT (12 bits): Round trip time to the remote DNS server for a UDP query, measured in units of 10 milliseconds.

validationStatus (12 bits): The result of the DNS UDP validation attempt. This field MUST be set to one of the DNS_IP_VALIDATE_RETURN_FLAGS (section 2.2.3.1.2).

Padding (20 bytes): This can be any value and MUST be ignored.