Setting the Name Resolution Search Order for TCP/IP-32

The Microsoft TCP/IP-32 stack uses various means to resolve a host name to an IP address of a given host. Four mechanisms are used; Local Cached Information, Hosts File, DNS Servers, and NetBIOS name resolution mechanisms. The default resolution order for resolving a host name is Local Cached Information -> Hosts File -> DNS Servers -> NetBt (NetBIOS over TCP/IP). NetBIOS over TCP/IP name resolution can consist of local subnet broadcasts.

Under most circumstances, the default resolution order does not need to be changed. However, if a change is necessary there are SYSTEM.INI parameters that you can use to alter this default behavior. This is done by using the four parameters: LocalPriority, HostsPriority, DnsPriority, and NetbtPriority. These parameters are Specified in the [DNS] section of the SYSTEM.INI file. Valid values can be between -32768 and 32767. The lower the value, the higher the priority in the search order. If you specify any of these parameters in the SYSTEM.INI, only those parameters specified will take effect, and none of the other resolution methods will be used.

Example

Will search the configured DNS server first, followed by the local HOSTS file. Local Cached Information and NetBIOS name resolution mechanisms would not be used.