DHCPv4, DHCPv4 Server Active Lease Cross Threshold

Contents

1Introduction
1.1Alarm Description
1.2Prerequisites

2

Procedure
2.1Changing Lease Threshold Configuration
2.2Adding More Pools
2.3Adding More Leases

1   Introduction

This instruction concerns alarm handling.

1.1   Alarm Description

This alarm is issued when the percentage of the active leases on server level exceeds the server threshold. Itis raised from one of the PL nodes, because all PL nodes share the lease pools.

The possible alarm causes and the corresponding fault reasons, fault locations, and impacts are described in Table 1.

Table 1    Alarm Causes

Alarm Cause

Description

Fault Reason

Fault Location

Impact

Solution

Inappropriate DHCPv4 configuration.

The value of server threshold is configured too low. And the percentage of the active leases is crossing the value.

The value of the option leasethreshold is configured too low. (For example, 10.)

DHCPv4 server

This alarm requests the operators to add more IP addresses. Otherwise, when all the IP pools are used up, DHCP client cannot get IP address.

See Section 2.1 Changing Lease Threshold Configuration

Allocated number of IP addresses exceeds the server threshold.

The percentage of allocated addresses exceeds the configured threshold.

The planning total number of IP addresses for DHCPv4 server is less than the actual requirement. This issue occurs when excessive users related to a specific server are online.

DHCPv4 server

See Section 2.2 Adding More Poolsand Section 2.3 Adding More Leases

Note:  
An alarm can appear as a result of the maintenance activity.

The alarm attributes are listed and explained in Table 2.

Table 2    Alarm Attributes

Attribute Name

Attribute Value

Major Type

193

Minor Type

872457

Managed Object Class

IpworksDhcpv4

Source

ManagedElement=<Node Name>,SystemFunctions=1,Fm=1,FmAlarmModel=ipworksDHCPv4,FmAlarmType=ipworksDhcpv4ServerActiveLeaseCrossThreshold

Specific Problem

DHCPv4, DHCPv4 Server Active Lease Cross Threshold

Event Type

qualityOfServiceAlarm(11)

Probable Cause

x733ThresholdCrossed(351)

Additional Text

The alarm is raised when the percentage of the server active leases exceeds the server threshold.;uuid:<Product_UUID>(1)

Perceived Severity

Minor

(1)  <Product_UUID> is the universally unique identifier (UUID) of machine that generates the alarm. The value can be fetched from /sys/devices/virtual/dmi/id/product_uuid on the PL node.


1.2   Prerequisites

This section provides information on the documents, tools, and conditions that apply to the procedure.

1.2.1   Documents

Before starting this procedure, ensure that you have read the following documents:

1.2.2   Tools

No tools are required.

1.2.3   Conditions

No conditions.

2   Procedure

This section describes the procedure to clear this alarm.

2.1   Changing Lease Threshold Configuration

Do the following:

  1. Change the configuration of Lease Threshold for DHCPv4 server. For example:

    #ipwcli

    #IPWorks> select dhcpv4server dhcp0

    #IPWorks> modify -remove option="leasethreshold <Original threshold>"

    #IPWorks> modify -add option="leasethreshold <New threshold>"

  2. Update DHCPv4 server.

    #IPWorks> update dhcpv4server

  3. Restart DHCPv4 server. For example:

    # ipw-ctr restart dhcp <PL hostname>

  4. Confirm that the alarm has ceased. If the alarm remains, consult the next level of maintenance support. Further actions are outside the scope of this instruction.

2.2   Adding More Pools

Do the following steps:

  1. Add more pools for DHCPv4 server. For example:

    # ipwcli

    #IPWorks> create pool pool1 -set addressrange=10.170.11.200-10.170.11.254 -set server=dhcp0

  2. Update DHCPv4 server.

    # IPWorks> update dhcpv4server

  3. Restart DHCPv4 server. For example:

    # ipw-ctr restart dhcp <PL hostname>

  4. Confirm that the alarm has ceased. If the alarm remains, consult the next level of maintenance support. Further actions are outside the scope of this instruction.

2.3   Adding More Leases

Do the following steps:

  1. Add more leases for the pool of DHCPv4 server. For example:

    # ipwcli

    #IPWorks> modify pool pool0 -set addressrange=10.170.15.101-140

  2. Update DHCPv4 server.

    # IPWorks> update dhcpv4server

  3. Restart DHCPv4 server. For example:

    # ipw-ctr restart dhcp <PL hostname>

  4. Confirm that the alarm has ceased. If the alarm remains, consult the next level of maintenance support. Further actions are outside the scope of this instruction.


    DHCPv4, DHCPv4 Server Active Lease Cross Threshold