Document revision date: 19 July 1999

The DECnet-Plus Starter Documentation Kit provides more information about DECnet-Plus. Table 21-6 lists the contents of this kit.

Table 21-6 DECnet-Plus Starter Documentation Kit

Manual	Description
DECnet-Plus for OpenVMS Release Notes	Describes changes to the software; installation, upgrade, and compatibility information; new and existing software problems and restrictions; and software and documentation corrections. You can print this text file from the configuration procedure.
DECnet-Plus for OpenVMS Introduction and User's Guide	Provides an introduction to networking on the system and includes user information.
DECnet-Plus for OpenVMS Installation and Basic Configuration	Explains how to install DECnet-Plus and perform the BASIC configuration option.
DECnet-Plus for OpenVMS Applications Installation and Advanced Configuration	Explains how to install and configure network applications and perform the ADVANCED configuration procedure option.
DECnet-Plus for OpenVMS Installation Quick Reference Card	Provides a quick reference for upgrading your system to DECnet-Plus during installation.
DECnet-Plus Planning Guide	Provides steps for transitioning from DECnet Phase IV functionality to DECnet Phase V.
DECnet-Plus for OpenVMS Network Management Quick Reference Guide	Provides a quick reference for DECnet-Plus network management.
DECnet-Plus for OpenVMS Network Management	Includes network management concepts and tasks for DECnet-Plus systems.
DECnet-Plus Network Control Language Reference	Provides command descriptions and examples for all NCL commands.
DECnet-Plus Problem Solving	Explains how to isolate and solve DECnet-Plus problems that can occur while the network is running, and how to perform loopback tests.

The DIGITAL TCP/IP Services for OpenVMS documentation set (refer to Table 21-7) provides more information about DIGITAL TCP/IP Services for OpenVMS.

Table 21-7 DIGITAL TCP/IP Service for OpenVMS Documentation Set

Manual	Description
Digital TCP/IP Services for OpenVMS Concepts and Planning	Introduces TCP/IP concepts and components and provides information to help you plan your software configuration.
Digital TCP/IP Services for OpenVMS Release Notes	Describes changes to the software; installation, upgrade, and compatibility information; new and existing software problems and restrictions; and software and documentation corrections.
Digital TCP/IP Services for OpenVMS Installation and Configuration	Describes how to install and configure DIGITAL TCP/IP Services for OpenVMS.
Digital TCP/IP Services for OpenVMS User's Guide	Provides user information.
Digital TCP/IP Services for OpenVMS Management	Provides information about managing and troubleshooting the TCP/IP software.
Digital TCP/IP Services for OpenVMS Management Command Reference	Provides reference information and examples of the TCP/IP Services for OpenVMS management commands.

This chapter describes how the LAN software works and the tasks you must perform to manage the LAN software on your system.

Information Provided in This Chapter

This chapter describes the following tasks:

Task	Section
Running the LANACP LAN server process	Section 22.3.1
Invoking and running LANCP	Section 22.4.1
Managing LAN devices	Section 22.5
Managing the LAN device databases	Section 22.6
Managing the LAN node databases	Section 22.7
Migrating from DECnet MOP to LAN MOP	Section 22.8.2
Using CLUSTER_CONFIG_LAN.COM and LAN MOP	Section 22.8.3
Managing the MOP downline load services	Section 22.9
Initiating the MOP console carrier	Section 22.9.8
Requesting MOP trigger boot	Section 22.9.9

This chapter explains the following concepts:

Concept	Section
Local area networks	Section 22.1
LANACP LAN server process	Section 22.3
LANCP utility	Section 22.4
MOP downline load services	Section 22.8

22.1 Understanding Local Area Networks

A local area network (LAN) provides a communications channel designed to connect information processing equipment in a limited area such as a room, a building, or a complex of buildings (for example, a campus). Nodes in a LAN can be linked by the following types of data transmission media:

• Ethernet---One of the earliest and the most common LANs. Ethernet can refer to either a general LAN application (for example, Ethernet address) or to the specific CSMA/CD (carrier sense multiple access with collision detection) technology that implements the Intel, Xerox, and DIGITAL intercompany Ethernet specifications.
  There are three types of Ethernet LANs as follows:
  • Ethernet (802.3) with transmission speeds of 10Mbps
  • Fast Ethernet (802.3u) with transmission speeds of 100Mbps
  • Gigabit Ethernet (802.3z) with transmission speeds of 1000Mbps
  
  All three types of Ethernet employ CSMA/CD protocol, and the same frame format and same frame size.
• Fiber Distributed Data Interface (FDDI) --- Implemented as dual-ring, token ring LANs.
• Token Ring---The IEEE 802.5 standard token passing ring.
• Asynchronous Transfer Mode (ATM)---The following standard is supported:
  • LAN emulation over ATM supports the ATM Forum's LAN Emulation V1.0 (LANE) standard.
  • Classical IP over ATM supports the RFC 1577 standard.

LAN controllers are devices that, along with additional external hardware, implement the Ethernet, FDDI, Token Ring, LAN emulation over ATM or Classical IP (RFC 1577) specifications. A LAN controller and the local system constitute a node. The LAN controller communicates with the local system through the system bus, and with remote systems implementing the Ethernet, FDDI, Token Ring, or LAN emulation over ATM specifications through the communication medium. (The Ethernet specification is described in The Ethernet--Data Link Layer and Physical Layer Specification. The FDDI specifications are available from ANSI. The Token Ring specifications are available from IEEE. The LAN emulation over ATM specifications are available from the ATM Forum.)

Application programs use the LAN driver's QIO interface to perform I/O operations to and from other nodes on the LAN. For detailed information about the QIO interface, refer to the OpenVMS I/O User's Reference Manual.

Table 22-1 provides a brief summary of the differences between the types of LAN media.

Table 22-1 Characteristics of LAN Media

Media	Speed	Maximum Frame Size	Maximum Cable Lengths+
Ethernet 802.3	10Mbps	1518 bytes	2.8 kilometers
Fast Ethernet 802.3u	100Mbps	1518 bytes	100Base-TX---100 meters 100Base-FX---412 meters (one-half duplex) -- 2000 meters (full-duplex)
Gigabit Ethernet 802.3z	1000Mbps	1518 bytes	1000Base-SX fiber optic -- 550 meters 1000Base-LX fiber optic---5 kilometers 1000Base-CX copper shielded---25 meters 1000BaseT copper UTP---100 meters
FDDI	100Mbps	4495 bytes	100 kilometers
Token Ring 802.5	4 or 16 Mbps	4462 bytes	300 meters
LAN emulation over ATM	155Mbps	1516, 4544, or 9234	Unrestricted

An Ethernet is a cable to which each system or device is connected by a single line. In an office or other area where personal computers and workstations are located, ThinWire Ethernet or unshielded twisted-pair cabling is usually used.

Individual systems can either be connected directly to an Ethernet or gain access to an Ethernet by means of a local area interconnect device, such as a DELNI. A DELNI serves as a concentrator, grouping systems together. Many similar devices, such as hubs, repeaters, and switches also provide the connectivity.

22.1.1.2 FDDI LANs

FDDI uses a dual ring of trees topology. It uses one ring as the primary ring, the other ring as a backup, and the tree configuration for increased flexibility, manageability, and availability.

FDDI networks and Ethernet networks can be combined to form a single extended LAN. This lets applications running on a system connected to FDDI communicate with applications that run on a system connected to Ethernet.

An FDDI concentrator provides for the attachment of FDDI devices such as VAX and Alpha nodes or FDDI-Ethernet bridges to the FDDI LAN.

22.1.1.3 Token Ring LANs (Alpha Only)

Token Ring controllers use either shielded or unshielded twisted pairs of wire to access the ring. Note that it is difficult to connect a Token Ring LAN directly bridged to any other type of LAN. However, routing protocols to other LANs work easily.

22.1.1.4 ATM LANs (Alpha Only)

LANs over ATM consists of a fiber-optic network based on cell switching. Compaq's ATM network uses AAL5 connection-oriented servers for data transmission. For LAN emulation over ATM, Compaq implements only the LAN emulation client (LEC) and does not implement the LAN emulation server (LES). The LAN emulation server must be provided by some other facility like the GIGAswitch/ATM. Compaq supports one LAN emulation client per ATM adapter.

22.1.1.5 Classical IP over ATM (Alpha Only)

Classical IP (CLIP) implements a new data-link level device that has the same semantics as an Ethernet interface (802.3). This interface is used by a TCP/IP protocol to transmit 802.3 (IEEE Ethernet) frames over an ATM network. The model that OpenVMS Alpha Version 7.2 follows for exchanging IP datagrams over ATM is based on RFC1577 (Classical IP over ATM).

22.1.2 LAN Addresses

Nodes on the LAN are identified by unique addresses. A message can be sent to one, several, or all nodes on the LAN simultaneously, depending on the address used.

Upon application, IEEE assigns a block of addresses to a producer of LAN nodes. Thus, every manufacturer has a unique set of addresses to use. Normally, one address out of the assigned block of physical addresses is permanently associated with each controller (usually in read-only memory). This address is known as the hardware address of the controller. Each controller has a unique hardware address.

A LAN address is 48 bits in length. LAN addresses are represented as six pairs of hexadecimal digits (six bytes) separated by hyphens (for example, AA-01-23-45-67-FF). The bytes are displayed from left to right in the order in which they are transmitted; bits within each byte are transmitted from right to left. In this example, byte AA is transmitted first; byte FF is transmitted last.

A LAN address can be a physical address of a single node or a multicast address, depending on the value of the low-order bit of the first byte of the address (this bit is transmitted first). The two types of node addresses are:

• Physical address---The unique address of a single node on a LAN. The least significant bit of the first byte of a physical address is 0. (For example, in physical address AA-00-03-00-FC-00, byte AA in binary is 1010 1010, and the value of the low-order bit is 0.)
• Multicast address---A multidestination address of one or more nodes on a given LAN. The least significant bit of the first byte of a multicast address is 1. (For example, in the multicast address 0B-22-22-22-22-22, byte 0B in binary is 0000 1011, and the value of the low-order bit is 1.)
  Token Ring devices do not support IEEE 802 standard multicast addresses. They do support functional addresses. A functional address is a locally administered group address that has 31 possible values. Each functional address sets one bit in the third through sixth bytes of the address, and bytes 1 and 2 are 03-00 (C0:00 in bit reversed format). To convert a multicast address to a functional address, use the SET DEVICE/MAP command.

The local area network (LAN) software includes two system management tools that work in conjunction with the OpenVMS LAN driver system software:

• Local Area Network Control Program (LANCP)
• LAN Auxiliary Control Program (LANACP) LAN server process

The LAN system management tools:

• Allow you to set LAN parameters to customize your LAN environment.
• Display LAN settings and counters.
• Provide Maintenance Operations Protocol (MOP) downline load support for devices such as terminal servers, x-terminals, and LAN-based printers, and for booting satellites in an OpenVMS Cluster environment. This MOP support provides an alternative to the traditional method of using either DECnet for OpenVMS or DECnet/OSI software.

Table 22-2 describes the LAN management software and the functionality supported on systems running OpenVMS Alpha and OpenVMS VAX.

Table 22-2 LAN System Management Enhancements

Utility	Description	OpenVMS Support
LAN Auxiliary Control Program (LANACP)	Runs as a server process whose primary function is to provide MOP downline load service. Other services include maintenance of a LAN volatile device database and a LAN volatile node database.	The LANACP utility provides identical functionality on VAX and Alpha systems running OpenVMS Version 7.0 and later.
LAN Control Program (LANCP)	Allows you to control LAN software parameters and obtain information from the LAN software. You can use the LANCP utility to: Obtain LAN device counters, revision, and configuration information Change the operational parameters of LAN devices on the system Maintain the permanent and volatile LAN device and node databases Update the firmware on LAN devices Control the LANACP LAN server process (including MOP downline load server related functions) Initiate MOP console carrier connections Send MOP trigger boot requests to other nodes	OpenVMS Alpha Version 6.1 contained the initial implementation of LANCP, which did not include MOP-related functions. OpenVMS Version 6.2 (VAX and Alpha) added MOP-related functions and extended some of this capability to VAX systems. The following table shows how the LAN utility functions are currently supported on VAX and Alpha systems: Function OpenVMS Alpha Version 7.2 OpenVMS VAX Version 7.2 Update firmware? Yes No Change operational parameters of LAN devices? Yes No Display LAN device information? Yes Limited Support MOP functions? Yes Yes

22.3 Understanding the LANACP LAN Server Process

You can run the LANACP LAN server process to provide the following services:

• Maintenance of the LAN volatile node database
• Maintenance of the LAN volatile device database
• MOP downline load

The LANCP utility allows you to issue instructions to the LANACP process.

Three principal files are connected with LANACP:

• SYS$SYSTEM:LANACP.EXE
  This file is the LANACP utility program.
• SYS$STARTUP:LAN$STARTUP.COM
  This file starts the LANACP server process.
• SYS$STARTUP:VMS$DEVICE_STARTUP.COM
  This file contains an entry that is used to start LANACP automatically at system startup.

In addition, four system logical names, described in Table 22-3, are associated with the LANACP LAN server process.

Table 22-3 LANACP System Logical Names

Component	Description
LAN$DLL	Defines the location of downline load files, where the location of the file is not provided in the load request or explicitly defined in the LAN volatile node database. By default, this is defined as SYS$SYSROOT:[MOM$SYSTEM].
LAN$NODE_DATABASE	Defines the location of the LAN permanent node database. By default, this is defined as SYS$COMMON:[SYSEXE]LAN$NODE_DATABASE.DAT.
LAN$DEVICE_DATABASE	Defines the location of the LAN permanent device database. By default, this is defined as SYS$SPECIFIC:[SYSEXE]LAN$DEVICE_DATABASE.DAT.
LAN$ACP	Defines the location of the LANACP LAN server process log file, containing entries describing changes to the LAN permanent device and node databases, and load request and load status information. By default, this is defined as SYS$MANAGER:LAN$ACP.LOG.

22.3.1 Running the LANACP LAN Server Process

To start the LANACP LAN server process, type @SYS$STARTUP:LAN$STARTUP at the DCL prompt.

22.3.2 Stopping the LANACP LAN Server Process

To stop the LANACP LAN server process, enter the SET ACP/STOP command at the LANCP utility prompt.

22.4 Understanding the LANCP Utility

The LANCP utility allows you to set and show LAN parameters. Section 22.4.1 describes how to invoke the LANCP utility. Table 22-4 describes LAN functions and provides section references to the LANCP commands that help you perform these functions.

Table 22-4 Functions of the LANCP Utility

Task	Section
Managing LAN devices	Section 22.5
Managing LAN device databases	Section 22.6
Managing LAN node databases	Section 22.7
Managing the MOP downline load service	Section 22.9
Initiating a MOP console carrier connection	Section 22.9.8
Sending MOP trigger boot requests	Section 22.9.9

22.4.1 Invoking and Running LANCP

Table 22-5 describes the ways you can invoke and run the LANCP utility (SYS$SYSTEM:LANCP.EXE).

Table 22-5 Invoking the LANCP Utility

Command	Example
Use the RUN command	At the DCL command prompt, enter: $ RUN SYS$SYSTEM:LANCP The LANCP utility displays the LANCP prompt at which you can enter LANCP commands.
Define LANCP as a foreign command	Either at the DCL prompt or in a startup or login command file, enter: $ LANCP :== $SYS$SYSTEM:LANCP Then, you can enter the command LANCP at the DCL prompt to invoke the utility and enter LANCP commands. When you enter the LANCP command: Without specifying any command qualifiers, the LANCP utility displays the LANCP prompt at which you can enter commands. With command qualifiers, the LANCP utility terminates after it executes the command and returns you to the DCL prompt.
Use the MCR command	At the DCL command prompt, enter: $ MCR LANCP When you enter the MCR LANCP command: Without specifying any command qualifiers, the LANCP utility displays the LANCP prompt at which you can enter commands. With command qualifiers, the LANCP utility terminates after it executes the command and returns you to the DCL prompt.

At the LANCP> prompt, you can enter LANCP commands.

For information about the LANCP utility, enter the HELP command at the LANCP> prompt.

To exit from the LANCP utility, enter the EXIT command or press Ctrl/Z at the LANCP> prompt.

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