EE connection network rules

All partner nodes on an EE connection network must be able to communicate with each other over the IP WAN.
Separate connection networks are needed for IPv4 and IPv6 traffic. If the TCP/IP stack supports both protocols, it can connect to both types of connection networks concurrently, if an IPv4 and an IPv6 local VIPA address have been defined to the stack.
If host names are used for EE connection networks, then for consistent results, ensure that a given fully qualified host name resolves to a single source VIPA address. If not, the address returned by DNS becomes unpredictable.
Host names are required when using IPv6 addressing. EE connection networks that use IPv6 addressing require name-to-address resolution for acquiring the source VIPA address of the local and remote EE endpoints.
EE connection networks that use IPv4 addressing can also use name-to-address resolution for acquiring the source VIPA address of the local and remote EE endpoints, if both endpoints are z/OS® V1R5 or later.