NBT (NetBIOS over TCP) name resolution Overview

In the Microsoft IP network, the primary means by which a client computer locates and communicates with another computer is by using domain name (DNS). However, using the previous version of Windows machine also uses the NetBIOS protocol to resolve the name to an IP address.

There are three ways to resolve NetBIOS names called IP addresses:

• Find in the Lmhosts file
• Local network segment broadcast
• Resolving through WINS servers

Windows resolves NetBIOS names using the following four methods. (The value in parentheses is the type of the WINS/NETBT node setting) The four methods are:

1. B-Node (broadcast,b broadcast, 0x1)

Windows uses broadcasts for name registration and name resolution, and the packets sent by a B-node client cannot exceed the scope of the LAN, depending on the configuration of the gateway. However, the B node is not suitable for large networks, in fact, Microsoft has modified the standard B-node type, when Windows tries to resolve the name, first check the LMHOSTS name cache, if this does not work, Windows will publish the broadcast, if the broadcast still fails, Windows will not check the actual Lmhosts file.

2. P-Node (per-to-per,p equivalence, 0x2)

This method does not use broadcasts, but rather registers their names on the WINS servers in the network when the computer starts, and sends a resolution request to the WINS server when the computer needs to resolve the name. This method is only valid when the WINS server is running correctly and cannot be resolved if the WINS server fails.

3. M-Node (mixed,m mixed, 0x4)

Windows uses the B node and the P node together, and the B node is used by default, and if the M node cannot use the broadcast for name resolution, it uses the P node's WINS server to do its work.

4. H-node (hybrid,h mixing, 0x8)

It is also a joint use of the B-node and P-nodes, but in the opposite way, if the use of WINS server is not successful, the work of the B-node is used to complete the work.