Communications Access Methods

About TCP/IP Internet Protocol (IP) Addressing

TCP/IP applications refer to networked computers via their fully qualified domain names (FQDN) and their IP addresses. Because IP addresses can change easily, SAS applications that contain hard-coded IP addresses are prone to maintenance problems. To avoid such problems, use of an FQDN is preferred over an IP address. The name-resolution system that is part of the TCP/IP protocol is responsible for locating the IP address that is associated with the FQDN.

SAS 9.2 introduces support for the next generation of Internet Protocol, IPv6, which is the successor to the current Internet Protocol, IPv4. Rather than replacing IPv4 with IPv6, SAS 9.2 supports both protocols. There will be a lengthy transition period during which the two protocols will coexist. A primary reason for the new protocol is that the limited supply of 32-bit IPv4 address spaces was being depleted. IPv6 will use a 128-bit address scheme, which provides more IP addresses than did IPv4.

Here are examples of an FQDN, an IPv6 address, and an IPv4 address:

d6292.us.company.com
db8::01
10.23.2.3

For details, see Internet Protocols in SAS Language Reference: Concepts.

Top of Page