An SMC-D configuration in which Ethernet provides the connectivity is shown in Figure D-15. An SMC-D configuration in which HiperSockets provide the connectivity is shown in  Figure D-16. 494  IBM z14 (3906) Technical Guide IP Subnet ‘A’ z/OS A (LP 1) z/OS B (LP 2) ISM Network (PNet X) OSA O SA QDIO QDIO PR/SM Ethernet (PNet X) ISM ISM ISM ISM IP Interface A.1 IP Interface A.2 VCHID X ISM Network ‘X’  becomes a “logical  extension” of the  external Layer 2  Network ‘X’ (Ethernet  LAN ‘X’)  Each host has an IP  network interface /  connection to a Layer 2  Network (with a defined  PNet ID X) associated with  IP subnet ‘A’ PNet X could be an  external LAN or an internal  HS Network (IQD VCHID  with PNet X) Both hosts have access to the  same IP subnet  PNet X PNet X ISM Network (PNet X) OSA could be a shared  OSA or each LP can use  unique OSAs IP Subnet ‘A’ z/OS A (LP 1) z/OS B (LP 2) ISM Network (PNet X) IQD IQD IQD IQD PR/SM IQD VCHID (PNet X) ISM ISM ISM ISM IP Interface A.1 IP Interface A.2 VCHID X ISM Network ‘X’  becomes a “logical  extension” of the  internal Layer 2  Network ‘X’ (IQD  Network ‘X’)  Each host has an IP  network interface /  connection to a Layer 2  Network (with a defined  PNet ID) associated with  IP subnet ‘A’  PNet X could be an  external LAN or an internal  HS Network (IQD VCHID  with PNet X) PNet X PNet X Both hosts use the same IP subnet  ISM Network (PNet X) Figure D-16 SMC-D configuration that uses HiperSockets to provide connectivity Figure D-15 SMC-D configuration that uses Ethernet to provide connectivity