Diagnostic Commands

Communication degradation or failure among nodes on the LAN can occur for many reasons. These include, for example, improper physical connections, hardware failure, configuration errors, excessive network traffic, and environmental factors. To correct node or network communication problems, the cause(s) must be isolated.

For each LAN/1000 node that is running Node Manager software, several commands provide limited diagnostic capability. These •Diagnostic Commands" provide problem isolation to three broad levels of node or network operation:

1.LANIC card operation using the card self"test.

2.Link operation from the LANIC card to the LAN coaxial cable medium (that is, the LANIC card, Attachment Unit Interface (AUI) cabling, Medium Attachment Unit (MAU), and LAN coaxial cable connections) using a LANIC card external loopback test.

3.Network operation from one LAN/1000 Link to another over the coaxial cable medium using IEEE 802.2 TEST and XID packets.

In general, the Node Manager software may be used to sequentially test node communications by issuing an appropriate command first at the card level, then the link level, and finally the network level. (Once isolated to a particular level, a problem may require other tools and resources for further isolation and correction.)

Using the Node Manager diagnostic commands, each node may be accessed locally, or remotely if communications are not completely severed. Diagnostic commands are listed below, and discussed on the following pages.

DLANIC Self"Test Command, TC

DDo External Loopback to MAU Command, EL

DIssue TEST Loopback Command, TEST

DXID Command Loopback Command, XID

The Rep Parameter

In each of the diagnostic commands, an optional parameter, Rep, provides for command repetition. The default value is •1", indicating the command is issued once only. A value up to •9999" is possible. A special value of •0" specifies continuous command repetition until a failure occurs, or the command is aborted.

When Rep is specified other than •1", a command completes and a response is returned to the user's terminal prior to another command cycle. Thus, Rep provides a repetitive loopback mechanism for transmissions to and from remote nodes.

5%34 Using Node Manager