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 BroadcastLMHOSTS file WINS DNS HOSTS file
LMHOSTS file HOSTS file HOSTS file   DNS
  DNS DNS    
More Info MS KB119493
More Info MS KB172218
More Info MS KB173161

Updated: 24 September 2007

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