Local Area Network (LAN)


A LAN provides local services based on the 48-bit address of the network interface card (NIC) attached to the computer. In particular, maintenance operations protocol (MOP)—which is required for booting cluster satellites, print servers, and terminal servers—is offered by LAN. LAN also supports cluster monitoring and management functions provided with SYSMAN and MONITOR.

MOP is also included in DECnet, so LAN is unnecessary when DECnet is installed. On the other hand, DECnet is a separately licensed product, and LAN is included in the OpenVMS license, so if DECnet is not required, LAN can support MOP and cluster needs.

LAN is managed with LANCP and LANACP. The LAN Control Program (LANCP) is used to examine and modify the network device database, to manage performance, to control LANACP, and to initiate MOP messages. For this purpose, LANCP supports about 20 commands. For instance, to show information about a device, the following command will produce a display similar to the following:

       LANCP> SHOW DEVICE/COUNTERS EXA0:       Device Counters EXA0:           Value    Counter           -----    -------          259225    Seconds since last zeroed         5890496    Data blocks received         4801439    Multicast blocks received          131074    Receive failure       764348985    Bytes received       543019961    Multicast bytes received               3    Data overrun         1533610    Data blocks sent          115568    Multicast packets transmitted          122578    Blocks sent, multiple collisions           86000    Blocks sent, single collision          189039    Blocks sent, initially deferred       198120720    Bytes sent        13232578    Multicast bytes transmitted         7274529    Send failure               0    Collision detect check failure               0    Unrecognized frame destination               0    System buffer unavailable               0    User buffer unavailable 

The LAN Auxiliary Control Program (LANACP) is the server (or symbiont or daemon) that receives messages from other nodes.




Getting Started with OpenVMS System Management
Getting Started with OpenVMS System Management (HP Technologies)
ISBN: 1555582818
EAN: 2147483647
Year: 2004
Pages: 130
Authors: David Miller

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