The communication between the TKE workstation and IBM LinuxONE servers occurs through  a TCP/IP connection, which is available through Ethernet LAN connectivity only. Note:  For more information about how to set up the TKE and managing master keys for  crypto domains, see  TKE Workstations User’s Guide , SC14-7511. To enable guests running under z/VM benefit from cryptographic hardware, crypto domains,  and crypto coprocessors must be attached to z/VM LPARS through HMC dialogues. After this  process is done, crypto domains can be dedicated to or shared with other LPARs. Connectivity in z/VM can be provided by customizing TCP/IP. The TCP/IP VM provides the  primary TCP/IP service that is called the  stack . The stack controls the network interfaces,  such as Open Systems Adapter (OSA), and supports the application programming interfaces  (APIs). For more information about how to set up and define the stack, see Chapter 19, “Configuring  the TCP/IP Server”, in  TCP/IP Planning and Customization ,  SC24-6331 . For TCP/IP to use network devices on z/VM, you must ensure that the device addresses are  attached to the TCP/IP VM by doing one of the following actions:  z/VM does not require a device definition in the system configuration file or HCPRIO. The  device attributes are determined automatically during device initialization. Example 3-14 shows the Device and Link configuration statements for an OSA device that is  found in the  PROFILE TCPIP  file.  Note:  Although system configuration is not required from an I/O standpoint, you might  need to code  RDEVICE  statements in SYSTEM CONFIG to set up the Equivalence ID  (EQID) for the QDIO devices in an SSI environment. In z/VM environment, the virtual servers that are connected to each other through a virtual  LAN (VLAN) which eliminates the requirement for any physical cabling or external networking  connection among them. Functioning as an internal LAN, it moves data at memory speed  between the virtual servers with high throughput and low latency communication path. VLAN 3.6.1 DEVICE and LINK statements 3.6 z/VM connectivity GLYPH<SM590000> Modify the  DTCPARMS  file to enable the necessary devices to be attached by using the  :Attach.  tag. GLYPH<SM590000> Add the appropriate  DEDICATE  control statements to the TCP/IP VM’s directory entry. DEVICE DEV§04B0 OSD 04B0 LINK OSA01 QDIOETHERNET DEV§04B0 PATHMTU 1500 VLAN 20 Example 3-14 DEVICE and LINK statements for an OSA device in the PROFILE TCPIP 50  Securing Your Cloud: IBM Security for LinuxONE