Planning Your Network; Tcp/Ip Networking Options For Linux - IBM ZVM - FOR LINUX V6 RELEASE 1 Getting Started

Planning your network

To use Linux, you need to connect to your TCP/IP network.
You need to determine:
v The device addresses of your network interface.
v The host name and domain name of your Linux virtual servers
v The IP address and the subnet mask
v Depending on the connectivity type, the broadcast name server and network
v Whether you plan to have your Linux virtual servers use the cryptographic

TCP/IP networking options for Linux

z/VM provides two broad categories for TCP/IP connectivity for Linux guests:
v Real network interfaces with connections to the LAN. A real network connection
v Virtual network interfaces, which allow the real connections to be shared,
The virtual switch is the preferred way to connect your Linux machines to the
network, but there are other legacy connection types. For more information, see
"Networking Options in z/VM" in z/VM: Connectivity, SC24-6174.
Figure 7 on page 31 is a diagram of a virtual switch called VSWITCH1. Coupled to
the virtual switch through NICDEF directory statements are Linux virtual servers.
The DTCVSW1 service virtual machine
the virtual switch controller. The full TCP/IP stack runs in the TCPIP service
virtual machine, the z/VM production TCP/IP. The two service virtual machines
are kept separate so you can operate them independently.
Due to the advantages of virtual switches, this document shows you how to set up
a virtual switch configuration only. IBM created the TCP/IP and user directory
2. A service virtual machine or service machine is virtual machine that provides a system service, such as accounting, error recording,
or monitoring.
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z/VM: Getting Started with Linux on System z
addresses.
facility for SSL acceleration.
may be through any device supported by Linux, including IBM Open Systems
Adapters and channel-attached devices. The real device (as defined in the
Input/Output Configuration Data Set) must be dedicated to the virtual machine
running Linux. You can do this by providing DEDICATE entries in the CP
directory entry for the virtual machine or by using the CP ATTACH command.
maximizing throughput. Virtual network connections include:
– Guest LAN. Through a guest LAN, z/VM simulates OSA-Express or
™
HiperSockets microcode to allow you to connect guest systems to
communication adapters. Such connections enable guests to communicate
through a LAN rather than through point-to-point connections. If the guests
require external connectivity, that connection requires a virtual machine acting
as a router between the guest LAN and the external connection.
– Virtual switch. A virtual switch is a special kind of guest LAN. In addition to
providing a network of virtual adapters, the switch can be connected directly
to an OSA-Express QDIO adapter. This capability allows you to gain
connectivity to external LAN segments without requiring a router, reducing
CPU utilization and latency associated with providing external connectivity
through a router.
2
, running a subset of the TCP/IP stack, is