gtpi1m3bSystem Installation Support Reference

DNS Select an IP Address

The Domain Name System (DNS) Select an Internet Protocol (IP) address user exit, UDNS, enables incoming TCP/IP connections to be load balanced across a TPF loosely coupled complex and provides two ways to answer a DNS query (address) request. The user exit is passed the TPF host name from the DNS request and a list of active IP addresses for the host name and their associated central processing unit (CPU) and IP type of information. You have the following three choices for selecting an IP address:

Input

The following four input parameters are passed to the user exit to determine which IP address will be passed back to the client:

Programming Considerations

The TPF server will select an IP address by a round-robin process if this user exit does not select one.

Return Values

A pointer to a structure defined in netdb.h containing one of the following: