HP-UX SNAplus2 R7 Administration Guide
Introduction to SNAplus2
SNAplus2 Components
Note
If the LAN is split by a network failure into two noncommunicating domains, each contain-
ing one or more backup servers, SNAplus2 cannot maintain a consistent configuration of
domain resources across the LAN. In this situation, each domain has an acting master server,
each tracking changes made to the domain configuration file in its own domain but unaware
of any changes made in the other domain. When the LAN connection is re-established, the
domain configuration file from the original master server becomes the domain configuration
file across the LAN, and any domain resource files on other servers are overwritten. (If the
master is inactive at this point, the domain configuration file from the highest backup server
available in either of the two domains is used.) Because changes to a domain configuration
file are not necessarily preserved when the connection is re-established, do not make any
changes to the file in either domain while the LAN connection is broken. Changes can still
be made to the configuration of individual nodes.
SNAplus2 stores information about the master server and backup servers in the binary file sna.net, known as
the SNA network data file. The master copy of this file is stored on the master server; any changes made to it
are automatically copied to all other servers in the same way that changes to the domain configuration file are
copied to backup servers. You cannot edit the contents of the SNA network data file directly; instead, SNAplus2
provides administration facilities (see Section 3.1,
Overview of SNAplus2 Administration) to access the file. (You
can edit node configuration files directly when SNAplus2 is not running; but in general you should use SNAplus2
administration facilities to ensure that all configuration information is valid and internally consistent.)
For more information about the SNA network data file, refer to HP-UX SNAplus2 Administration Command
Reference.
HP-UX Clients
UNIX
A client computer does not contain a configuration file or SNA network data file. Instead, the client has a client
network data file that holds the information it needs to access servers on the SNAplus2 LAN. The client relies on
a server to provide the necessary configuration information.
Most of the details of using HP-UX client computers are the same as those for a server, except that the client has
no node resources to define and manage. The following references provide more details about using a client:
• To start and stop the SNAplus2 software, see Chapter 3, Administering SNAplus2.
• To set up information required to support invokable TPs on the client, see Section 7.4, Defining TPs.
• To manage the SNA network information required to access servers on the SNAplus2 LAN, see Chapter 11,
Managing SNAplus2 Client/Server Systems or refer to HP-UX SNAplus2 Administration Command Reference.
• To manage diagnostics information (logging and tracing), see Section 3.1.2, Administration Tools, or for more
detailed information, refer to HP-UX SNAplus2 Diagnostics Guide.
Windows Clients
WINDOWS
SNAplus2 enables machines running Microsoft Microsoft Windows 2000, Windows XP, Windows Server 2003,
Windows 3.1, Windows for Workgroups 3.11, or OS/2 to act as clients in the SNAplus2 domain.
You can run either a 16-bit version of the SNAplus2 client software (referred to in this guide as “Win16”)ora
32-bit version (referred to in this guide as “Win32”):
• The 16-bit version can be installed on machines running Windows 3.1 or Windows for Workgroups 3.11, or on
Win16 subsystems on Windows NT, Windows 95, or OS/2. SNA network information, and other configuration
information required by Win16 clients, is held in the sna.ini file.
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