Description of host name resolution order
In a computer-network each computer have a unique physical address, but the physical address can be difficult to use, so instead one gives each computer a name (logical address). This introduces the problem of converting the logical address to the physical address, also called host name resolution. There are different methods available to perform this resolution:
- TCPIP
- HOSTS file. Uses a text-file placed locally to perform the resolution.
- DNS. Sends a resolution-message to a Domain Name Server (DNS) and it performs the resolution.
- NetBIOS
- LMHOSTS file. Uses a text-file placed locally to perform the resolution. More Info MS KB101927
- Broadcast. Sends a resolution-message to every computer in the network. Bad for networks with many computers.
- WINS. Sends a resolution-message to a NetBIOS Name Server (NBNS) aka. Windows Internet Naming Service (WINS) and it performs the resolution.
There are different ways available for how to order the different methods. When a method fails to convert the logical-address to a physical-address within the timeout, then the next in the order is used until one succeeds or all fails. One should use the method-order that introduces the fewest timeouts and minimizes broadcasts and doesn’t have a single point of failure.
- TCPIP-DNS: The default setting for Windows installations is to use DNS first.
- NetBIOS (H)ybrid-Node: The default setting when using NetBIOS first and have WINS configured.
- NetBIOS (M)ixed-Node: Broadcast is used in local subnet and WINS used to reach computers in remote subnet.
- NetBIOS (P)oint To Point-Node: When the WINS stops responding the whole network is down.
- NetBIOS (B)broadcast-Node: The default setting when using NetBIOS first and don’t have WINS configured (Introduces a lot of resolution-traffic when on a large network)
| TCPIP-DNS | (H)ybrid-Node | (M)ixed-Node | (P)oint To Point-Node | (B)roadcast-Node |
|---|---|---|---|---|
| HOSTS file | NetBIOS name cache | NetBIOS name cache | NetBIOS name cache | NetBIOS name cache |
| DNS | WINS | NetBIOS Broadcast | WINS | NetBIOS Broadcast |
| WINS | NetBIOS Broadcast | LMHOSTS file | HOSTS file | LMHOSTS file |
| NetBIOS Broadcast | LMHOSTS file | WINS | DNS | HOSTS file |
| LMHOSTS file | HOSTS file | HOSTS file | DNS | |
| DNS | DNS |
- Configure host name resolution order in Win9x/WinMe
- Configure host name resolution order in WinNT/Win2k
More Info MS KB119493
More Info MS KB172218
More Info MS KB173161