If native IPv6 connectivity does not exist between two IPv6 sites, IPv6 over IPv4 tunneling can be used to provide IPv6 connectivity to the two sites. z/OS® Communications Server TCP/IP can make use of an IPv6 over IPv4 tunnel to send packets to a remote site, but cannot be used as a tunnel endpoint itself. Instead, an intermediate router which supports IPv6 over IPv4 tunneling must act as the tunnel endpoint.

See Enabling IPv6 communication between IPv6 nodes or networks in an IPv4 environment for more information about IPv6 over IPv4 tunnels.