HP OpenVMS Systems Documentation
OpenVMS System Manager's Manual
23.8.1 DECnet-Plus Node Names
The following examples show node full names for the Local namespace, DECdns, and DNS/BIND, respectively:
The system stores a full name as you enter it, preserving uppercase and lowercase entries. However, when matching an entry with a stored full name, the system is case insensitive; in other words, if the user enters Acme, the system recognizes it as equivalent to ACME.
For more information about full names, refer to the DECnet-Plus
DECnet-Plus software supports OpenVMS Cluster systems and the use of cluster aliases. DECnet-Plus allows for three aliases for each OpenVMS Cluster. DECnet Phase IV nodes cannot be DECnet-Plus alias members. (A separate alias must be configured for use with DECnet Phase IV nodes.)
The CLUSTER_CONFIG.COM command procedure performs an OpenVMS Cluster
configuration. It can configure all members of a cluster from any
cluster member. It invokes the DECnet-Plus for OpenVMS
NET$CONFIGURE.COM command procedure to perform any required
modifications to NCL initialization scripts. Use CLUSTER_CONFIG.COM to
configure an OpenVMS Cluster. Use NET$CONFIGURE.COM directly to
configure additional DECnet-Plus satellite nodes once
CLUSTER_CONFIG.COM has already been used.
DECnet-Plus for OpenVMS provides a variety of network tools that let you perform the following tasks:
23.9 Preparing to Join a DECnet-Plus Network
Before configuring your DECnet-Plus node, you must make some decisions regarding addressing, the use of name services, time services, and routers. You must also be aware of license dependencies unique to X.25 software.
For detailed planning information, refer to the DECnet-Plus Planning Guide.
You can install DECnet-Plus for OpenVMS software on your system in either of the following ways:
Once the DECnet-Plus software is installed successfully, you invoke a menu-based configuration procedure to configure the software according to the unique characteristics of your system and network:
For detailed installation and configuration information, refer to the
DECnet-Plus for OpenVMS Installation and Basic Configuration manual.
The DECnet over TCP/IP feature extends the DECnet Phase V architecture to coexist and communicate with TCP/IP networks. This feature requires a valid DECnet license and a licensed and installed TCP/IP product that supports the PATHWORKS Internet Protocol (PWIP) interface.
You should consider enabling DECnet over TCP/IP for the following purposes:
With DECnet over TCP/IP, you can:
The DECnet over TCP/IP functionality uses TCP/IP to form a logical link between DECnet nodes. It uses the PATHWORKS IP Driver to interface with TCP. DECnet applications run transparently between DECnet nodes connected by TCP/IP. Users on those DECnet nodes can connect to each other using DECnet node synonyms or IP fullnames. For example:
To enable DECnet over TCP/IP on your system, you must do the following primary tasks:
For detailed information about enabling and using DECnet over TCP/IP,
refer to the DECnet-Plus for OpenVMS Applications Installation and Advanced Configuration and DECnet-Plus for OpenVMS Network Management manuals.
If you are planning to transition your network from DECnet Phase IV to DECnet-Plus, you can move portions of the network to DECnet-Plus or move the entire network. Because DECnet-Plus is backward compatible, you can choose to run your system and the network in the same manner as you have before, using DECnet Phase IV applications, routing, and so forth. You can implement the additional functionality available to you from DECnet-Plus any time you are ready. The changes mostly involve network management. They are almost entirely transparent to users and applications.
A number of automated tools (DECnet transition utilities and the NCP Emulator) are available, in addition to the simplified configuration procedures, to help ease the transition to full DECnet-Plus functionality.
For detailed information about transitioning your network, refer to the
DECnet-Plus Planning Guide manual.
If you install DECnet-Plus from the OpenVMS installation menu, the software starts automatically. If you need to restart DECnet-Plus for any reason (for example, after shutting down the network by executing SYS$STARTUP:NET$SHUTDOWN.COM), enter the following command:
To shut down DECnet-Plus software, which disables and deletes various network entities on your system, enter:
23.14 DECnet-Plus Documentation
Table 23-4 lists the documentation that supports the DECnet-Plus for OpenVMS software. For complete information about how to plan for, install, configure, and manage DECnet-Plus, refer to these documents.
|Running the LANACP LAN server process||Section 24.3.1|
|Invoking and running LANCP||Section 24.4.1|
|Managing LAN devices||Section 24.5|
|Managing the LAN device databases||Section 24.6|
|Managing the LAN node databases||Section 24.7|
|Migrating from DECnet MOP to LAN MOP||Section 24.8.2|
|Using CLUSTER_CONFIG_LAN.COM and LAN MOP||Section 24.8.3|
|Managing the MOP downline load services||Section 24.9|
|Initiating the MOP console carrier||Section 24.9.8|
|Requesting MOP trigger boot||Section 24.9.9|
This chapter explains the following concepts:
|Local area networks||Section 24.1|
|LANACP LAN server process||Section 24.3|
|LANCP utility||Section 24.4|
|MOP downline load services||Section 24.8|
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:
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 24-1 provides a brief summary of the differences between the types of LAN media.
|10Mbps||1518 bytes||100 meters|
100Base-FX---412 meters (one-half duplex)
-- 2000 meters (full-duplex)
|1000Mbps||1518 or 9018 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||40 kilometers|
|4 or 16 Mbps||4462 bytes||300 meters|
|LAN emulation over ATM||
|1516, 4544, or 9234||2 kilometers, 300 meters|
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.
18.104.22.168 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.
22.214.171.124 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.
126.96.36.199 ATM LANs (Alpha Only)
LANs over ATM consist of a connection-oriented network based on cell switching. The OpenVMS ATM network uses AAL5 ATM adaption layer for data transmission.
For LAN emulation over ATM, OpenVMS implements only the LAN emulation client (LEC) and does not implement the LAN emulation server (LES), the Broadcast and Unknown (BUS), or the LAN emulation Configuration Server (LECS). The LES, BUS, and LECS must be provided by some other facility such as the ATM switch. OpenVMS supports eight LAN emulation clients per ATM adapter.
Classical IP over ATM (CLIP) implements a 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 follows for exchanging IP
datagrams over ATM is based on RFC1577 (Classical IP over ATM).
24.1.2 LAN Addresses
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: