By default, Oracle GoldenGate selects a socket in the following order of priority to ensure the best chance of connection success:

• IPv6 dual-stack

• IPv4 if IPv6 dual-stack is not available

• IPv6

If your network has IPv6 network devices that do not support dual-stack mode, you can use the USEIPV6 parameter to force Oracle GoldenGate to use IPv6 for all connections. This is a GLOBALS parameter that applies to all processes of an Oracle GoldenGate instance. When USEIPV6 is used, the entire network must be IPv6 compatible to avoid connection failures. See USEIPV6 in Reference for Oracle GoldenGatefor more information.