Windows Internet Name Service(WINS)

Chapter 16

Windows Internet Name Service(WINS)

Network Basic Input/Output System (NetBIOS)

● NetBIOS over TCP/IP (NetBT)

provides commands and support for network name registration and verification. session establishment and termination. reliable connection-oriented session data transfer. unreliable connectionless datagram data transfer. adapter monitoring and management.

the operation of the NetBIOS protocol over the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP) of the TCP/IP protocol stack.

NetBT Name Service Messages Name Query Request

Name Query Response

Name Registration Request

Name Registration Response

Wait Acknowledgment

Name Refresh Request

Name Release Request

Name Release Response

NetBT Name Service Messages

Question entries Variable legth

Answer RRs Variable length

Authority RRs Variable length

Additional RRs Variable length

• Name Service header Fixed length (12 bytes long)

Name Service header

Transaction ID > 2-byte

Flags > 2-byte

Question Entry Count > 2-byte

Answer RR Count > 2-byte

Authority RR Count > 2-byte

Additional RR Count > 2-byte

The Flags field in the Name Service header

Request/Response > 1-bit

Operation Code > 4-bit

Authoritative Answer > 1-bit

Truncation > 1-bit

Recursion Desired > 1-bit

Recursion Available > 1-bit

Reserved > 3-bit

Return Code > 4-bit

NetBIOS Name Representation

The 16-character NetBIOS name is converted into a 32-byte ASCII representation.

The period (.) character and the NetBIOS scope identifier are appended to the 32-byte ASCII representation of the NetBIOS name.

The resulting name is then encoded using length-value format according to the rules for

fully qualified domain names (FQDNs) in DNS Name Query Request messages.

Creating the DNS form of a NetBIOS name for NetBIOS name service messages involves the followingsteps:

Question RR FormatQuestion entry format

RR format in NetBIOS name service messages

Question Name

Question Type

Question Class

RR Name

Record Type

Record Class

Time to Live

Resource Data Length

Resource Data

Format for General Name Service RRs

Question RR Format

RR Name Record Type

Record Class Time to Live

Resource Data Length Data Flags IP Address

Format of the RDATA flags field

Group Flag

Owner Node Type

Reserved

Question RR Format

Question RR Format

WINS Client and Server Message Exchanges

Resolving NetBIOS names to IP addresses Registering NetBIOS names Renewing NetBIOS names Releasing NetBIOS names

This section describes common message exchanges between WINS clients and servers for the following:

Resolving NetBIOS Names to IP Addresses

Resolving NetBIOS Names to IP Addresses

Registering NetBIOS Names

Resolving NetBIOS Names to IP Addresses

Registering NetBIOS Names

Refreshing NetBIOS Names

Refreshing NetBIOS Names

Releasing NetBIOS Names

Releasing NetBIOS Names

Summary

Name Query Request Name Query Response messages Name Query Response

Name Registration Request Name Registration Response

WACKName Registration Response

Name Refresh Request

Registration Response Name Release Request

Name Release Response

WINS-based NetBIOS name resolution

NetBIOS name registration

NetBIOS name refresh

NetBIOS name release

fixed-size

variable-sized