Contents

1   Overview

This section provides an overview for the Control, Remote Node Unreachable alarm.

1.1   Description

This alarm is raised by the System Monitor (SM) leader of a CUDB site, if it is unable to communicate with any other CUDB node of the same site.

The alarm attributes are listed and explained in Table 1.

Table 1    Alarm Attributes

Attribute Name	Attribute Value
Auto Cease	Yes
Module	CONTROL
Error Code	1
Timestamp First	Date and time when the alarm was raised for the first time.
Repeated Counter	Number which indicates how many times the alarm was raised.
Timestamp Last	Date and time of the most recent alarm raise.
Resource ID	.1.3.6.1.4.1.193.169.7.1.<CN>
Alarm Model Description	Remote CUDB node unreachable, Control.
Alarm Active Description	Control: CUDB node <CN> unreachable
ITU Alarm Event Type	communicationsAlarm (2)
ITU Alarm Probable Cause	communicationsSubsystemFailure (505)
ITU Alarm Perceived Severity	(3) - Critical
Originating source IP	Node IP where the alarm was raised.
Sequence Number	Number which indicates the order in which the alarms are raised.

In Table 1, the indicated variables are as follows:

• <CN> is the identifier of the unreachable CUDB node (refer to CUDB Node Configuration Data Model Description, Reference [1], for further information).

For further information about attribute descriptions, refer to CUDB Node Fault Management Configuration Guide, Reference [2].

The possible causes are as follows:

• Network outages.
• CUDB node failure.

1.2   Prerequisites

This section lists the prerequisites required for the procedure described in Section 2.

1.2.1   Documents

Refer to CUDB System Administrator Guide, Reference [3], for further information.

1.2.2   Tools

Not applicable.

1.2.3   Conditions

Not applicable.

2   Procedure

Perform the following steps:

1. Check if the Control, Potential Split Brain Detected alarm is raised. If so, follow the procedure described in the Operating Instruction describing this alarm (Control, Potential Split Brain Detected, Reference [4]).
2. Try to connect offline (for example, from an external system) to a node of the unreachable site or use other measures to check if the problem is caused by a network issue. If the failure is due to network issues, the troubleshooting steps are not in the scope of this Operating Instruction.
3. Check for possible infrastructure problems related to the communication between CUDB nodes (in switches, network connections, and so on), and fix them.
4. If the alarm does not cease, consult the next level of maintenance support.

Glossary

For the terms, definitions, acronyms and abbreviations used in this document, refer to CUDB Glossary of Terms and Acronyms, Reference [5].

Reference List

CUDB Documents
[1] CUDB Node Configuration Data Model Description.
[2] CUDB Node Fault Management Configuration Guide.
[3] CUDB System Administrator Guide.
[4] Control, Potential Split Brain Detected.
[5] CUDB Glossary of Terms and Acronyms.