This section describes the network stack selection mechanism when both IPv4 and IPv6 network stacks are enabled on a machine.
When both IPv4 and IPv6 network stacks are enabled on a machine, the connection binds to either of the two network stacks based on the host name and local address properties.
The host name is specified by any of these properties, XMSC_WMQ_HOST_NAME, XMSC_RTT_HOST_NAME, and XMSC_WPM_PROVIDER_ENDPOINTS, while the local address may be determined by XMSC_WMQ_LOCAL_ADDRESS, XMSC_RTT_LOCAL_ADDRESS, or XMSC_WPM_LOCAL_ADDRESS.
Stack | Host Name | Local Address | Connection result |
---|---|---|---|
IPv4 only stack | IPv4 address | None | Connection binds to IPv4 stack |
IPv6 address | None | Connection fails to resolve host name | |
Host name resolves to both IPv4 and IPv6 addresses | None | Connection binds to IPv4 stack | |
IPv4 address | IPv4 address | Connection binds to IPv4 stack | |
IPv6 address | IPv4 address | Connection fails to resolve host name | |
Remote host name resolves to both IPv4 and IPv6 addresses | IPv4 address | Connection binds to IPv4 stack | |
Any address | IPv6 address | Connection fails to resolve local address | |
IPv4 address | Local address resolves to both IPv4 and IPv6 addresses | Connection binds to IPv4 stack | |
IPv6 address | Local address resolves to both IPv4 and IPv6 addresses | Connection fails to resolve host name | |
Remote host name resolves to both IPv4 and IPv6 addresses | Local address resolves to both IPv4 and IPv6 addresses | Connection binds to IPv4 stack | |
Dual (IPv4 and IPv6) stack | IPv4 address | None | Connection binds to IPv4 stack |
IPv6 address | None | Connection binds to IPv6 stack | |
Remote host name resolves to both IPv4 and IPv6 addresses | None | For WPM and RTT, connection binds to IPv6 stack. For WebSphere MQ, channel binds to stack determined by the value of the environment variable. |
|
IPv4 address | IPv4 address | Connection binds to IPv4 stack | |
IPv6 address | IPv4 address | Connection fails to resolve host name | |
Remote host name resolves to both IPv4 and IPv6 addresses | IPv4 address | Connection binds to IPv4 stack | |
IPv4 address | IPv6 address | Maps an IPv4 host name to an IPv4 mapped IPv6 address. IPv6 implementations that do not support IPv4 mapped IPv6 addressing fail to resolve host name. | |
IPv6 address | IPv6 address | Connection binds to IPv6 stack | |
Remote host name resolves to both IPv4 and IPv6 addresses | IPv6 address | Connection binds to IPv6 stack | |
IPv4 address | Local address resolves to both IPv4 and IPv6 addresses | Connection binds to IPv4 stack | |
IPv6 address | Local address resolves to both IPv4 and IPv6 addresses | Connection binds to IPv6 stack | |
Remote host name resolves to both IPv4 and IPv6 addresses | Local address resolves to both IPv4 and IPv6 addresses | For WPM and RTT, connection binds to IPv6 stack. For WebSphere MQ, channel binds to stack determined by the value of the environment variable. |
|
IPv6 only stack | IPv4 address | None | Maps an IPv4 host name to an IPv4 mapped IPv6 address. IPv6 implementations that do not support IPv4 mapped IPv6 addressing fail to resolve host name |
IPv6 address | None | Connection binds to IPv6 stack | |
Remote host name resolves to both IPv4 and IPv6 addresses | None | Connection binds to IPv6 stack | |
Any address | IPv4 address | Connection fails to resolve local address | |
IPv4 address | IPv6 address | Maps an IPv4 host name to an IPv4 mapped IPv6 address. IPv6 implementations that do not support IPv4 mapped IPv6 addressing fail to resolve host name | |
IPv6 address | IPv6 address | Connection binds to IPv6 stack | |
Remote host name resolves to both IPv4 and IPv6 addresses | IPv6 address | Connection binds to IPv6 stack | |
IPv4 address | Local address resolves to both IPv4 and IPv6 addresses | Maps an IPv4 host name to an IPv4 mapped IPv6 address. IPv6 implementations that do not support IPv4 mapped IPv6 addressing fail to resolve host name | |
IPv6 address | Local address resolves to both IPv4 and IPv6 addresses | Connection binds to IPv6 stack | |
Remote host name resolves to both IPv4 and IPv6 addresses | Local address resolves to both IPv4 and IPv6 addresses | Connection binds to IPv6 stack |