Module 3: Managing and Monitoring

Dynamic Host Configuration Protocol (DHCP)

Overview

Managing a DHCP Database

Monitoring DHCP

Applying Security Guidelines for DHCP

Lesson: Managing a DHCP Database

Overview of Managing DHCP

What Is a DHCP Database?

How a DHCP Database Is Backed Up and Restored

How To Back Up and Restore a DHCP Database

How a DHCP Database Is Reconciled

How To Reconcile a DHCP Database

Overview of Managing DHCP

The DHCP service needs to be managed to reflect changes in the network and the DHCP server The DHCP service needs to be managed to reflect changes in the network and the DHCP server

Scenarios for managing DHCP:Scenarios for managing DHCP:

Managing DHCP database growth

Protecting the DHCP database

Ensuring DHCP database consistency

Adding clients

Adding new network service servers

Adding new subnets

Managing DHCP database growth

Protecting the DHCP database

Ensuring DHCP database consistency

Adding clients

Adding new network service servers

Adding new subnets

What Is a DHCP Database?

The DHCP database is a dynamic database that is updated when DHCP clients are assigned or as they release their TCP/IP address leases

The DHCP database is a dynamic database that is updated when DHCP clients are assigned or as they release their TCP/IP address leases

The DHCP database contains DHCP configuration data, such as information about scopes, reservations, options, and leases

Windows Server 2003 stores the DHCP database in the directory %Systemroot%\System32\Dhcp The DHCP database files include:

DHCP.mdb Tmp.edb J50.log and J50*.log

DHCP.mdb Tmp.edb J50.log and J50*.log

Res*.log J50.chk

Res*.log J50.chk

DHCP ServerDHCP Server

DHCP

DHCP

Offline StorageOffline Storage

How a DHCP Database Is Backed Up and Restored

Back up

The DHCP service automatically backs up the DHCP database to the backup directory on the local driveThe DHCP service automatically backs up the DHCP database to the backup directory on the local drive

Restore

Back up

Restore

If the original database is unable to load, the DHCP service automatically restores from the backup directory on the local driveIf the original database is unable to load, the DHCP service automatically restores from the backup directory on the local driveThe administrator moves a copy of the backed up DHCP database to an offline storage locationThe administrator moves a copy of the backed up DHCP database to an offline storage locationIn the event that the server hardware fails, the administrator can restore only from the offline storage locationIn the event that the server hardware fails, the administrator can restore only from the offline storage location

How to Back Up and Restore a DHCP Database

Your instructor will demonstrate how to:Your instructor will demonstrate how to:

Apply guidelines when backing up and restoring a DHCP database

Configure a DHCP database backup path

Manually back up a DHCP database to the backup directory on a local drive

Manually restore a DHCP database from the backup directory on a local drive

Apply guidelines when backing up and restoring a DHCP database

Configure a DHCP database backup path

Manually back up a DHCP database to the backup directory on a local drive

Manually restore a DHCP database from the backup directory on a local drive

How a DHCP Database Is Reconciled

Example

Summary information Detailed information Reconciled DHCP database

Client has IP address 192.168.1.34

IP address 192.168.1.34 is available Create an active lease entry

DHCP ServerDHCP Server

DHCPDatabase

Registry Summary IP address lease information

Summary IP address lease information

Detailed IP address lease information

Detailed IP address lease information Compares

information to find inconsistencies

Compares information to find

inconsistencies

Reconciles inconsistencies in

the DHCP database

Reconciles inconsistencies in

the DHCP database

How to Reconcile a DHCP Database

Your instructor will demonstrate how to:Your instructor will demonstrate how to:

Prepare to reconcile a DHCP database

Reconcile all scopes in a DHCP database

Reconcile a scope in a DHCP database

Prepare to reconcile a DHCP database

Reconcile all scopes in a DHCP database

Reconcile a scope in a DHCP database

Practice: Managing a DHCP Database

In this practice, you will manage a DHCP database

Lesson: Monitoring DHCP

Overview of Monitoring DHCP

Multimedia: Creating a Performance Baseline (Optional)

What Are DHCP Statistics?

How to View DHCP Statistics

What Is a DHCP Audit Log File?

How DHCP Audit Logging Works

How to Monitor DHCP Server Performance by Using the DHCP Audit Log

Guidelines for Monitoring DHCP Server Performance

Common Performance Counters for Monitoring DHCP Server Performance

Guidelines for Creating Alerts for a DHCP Server

Overview of Monitoring DHCP

Why monitor DHCP?Why monitor DHCP?

The DHCP environment is dynamic

Increased DHCP server performance

Provides the ability to plan for current and future needs

The DHCP environment is dynamic

Increased DHCP server performance

Provides the ability to plan for current and future needs

DHCP data includes:DHCP data includes:

DHCP statistics

DHCP events

DHCP performance data

DHCP statistics

DHCP events

DHCP performance data

Multimedia: (Optional) Creating a Performance Baseline

The objective of this presentation is to provide high-level steps for creating a performance baseline

After this presentation, you will be able to:

Explain the purpose of a performance baseline

Explain that a performance baseline is the level of system performance that you find acceptable

Explain that server performance is critical to efficient network operations

What Are DHCP Statistics?

DHCP statistics represent statistics collected at either the server level or scope level since the DHCP service was last started DHCP statistics represent statistics collected at either the server level or scope level since the DHCP service was last started

DHCP ServerDHCP Server

How to View DHCP Statistics

Your instructor will demonstrate how to:Your instructor will demonstrate how to:

Enable DHCP statistics to automatically refresh

View DHCP server statistics

View DHCP scope statistics

Enable DHCP statistics to automatically refresh

View DHCP server statistics

View DHCP scope statistics

What Is a DHCP Audit Log File?

A DHCP audit log is a log of service-related events, such as when: the service starts and stops; authorizations have been verified; or IP addresses are leased, renewed, released, or denied

A DHCP audit log is a log of service-related events, such as when: the service starts and stops; authorizations have been verified; or IP addresses are leased, renewed, released, or denied

How DHCP Audit Logging Works

3. DHCP closes daily audit log

2. DHCP performs disk checks

1. DHCP opens daily audit log

DHCP server writes a header message in the

audit log, indicating that logging has started

DHCP server writes a header message in the

audit log, indicating that logging has started

Disk checks ensure that both the ongoing availability of server disk space and the current audit log file do not become too large or grow

too rapidly

Disk checks ensure that both the ongoing availability of server disk space and the current audit log file do not become too large or grow

too rapidly

DHCP server closes the existing log and moves to

the log file for the next day of the week

DHCP server closes the existing log and moves to

the log file for the next day of the week

DHCPSrvLog-Mon.LogDHCPSrvLog-Mon.LogDHCPSrvLog-Tue.LogDHCPSrvLog-Tue.Log

Audit logging is the daily collection of DHCP server events into log files. Audit logging is the daily collection of DHCP server events into log files.

12:00 am12:00 am

How to Monitor DHCP Server Performance by Using the DHCP Audit Log

Your instructor will demonstrate how to:Your instructor will demonstrate how to:

Enable and configure DHCP audit logging

View the DHCP audit log

Enable and configure DHCP audit logging

View the DHCP audit log

Guidelines for Monitoring DHCP Server Performance

Create a baseline of performance data on the DHCP serverCreate a baseline of performance data on the DHCP server

Check the standard counters for server performance, such as processor utilization, paging, disk performance, and network utilization

Check the standard counters for server performance, such as processor utilization, paging, disk performance, and network utilization

Review DHCP server counters to look for significant drops or increases that indicate a change in DHCP traffic

Review DHCP server counters to look for significant drops or increases that indicate a change in DHCP traffic

Common Performance Counters for Monitoring DHCP Server Performance

Performance counters

What to look for after a baseline is established

Packets received/second

Monitor for sudden increases or decreases which could reflect problems on the network

Requests/second Monitor for sudden increases or decreases which could reflect problems on the network

Active queue length

Monitor for increases both sudden and gradual which could reflect increased load or decreased server capacity

Duplicates dropped/second

Monitor for any activity which could indicate that more than one request is being transmitted on behalf of clients

Guidelines for Creating Alerts for a DHCP Server

Define the acceptable level that a DHCP counter can rise above or fall below, before creating an alert Define the acceptable level that a DHCP counter can rise above or fall below, before creating an alert

Use scripts with your alertsUse scripts with your alerts

Practice: Monitoring DHCP

In this practice, you will monitor DHCP

Lesson: Applying Security Guidelines for DHCP

Guidelines for Restricting an Unauthorized User from Obtaining a Lease

Guidelines for Restricting an Unauthorized, non-Microsoft DHCP Server from Leasing IP Addresses

Guidelines for Restricting Who Can Administer the DHCP Service

Guidelines for Securing the DHCP Database

Guidelines for Restricting an Unauthorized User from Obtaining a Lease

To restrict an unauthorized user from obtaining a lease:To restrict an unauthorized user from obtaining a lease:

Ensure that unauthorized persons do not have physical or wireless access to your networkEnsure that unauthorized persons do not have physical or wireless access to your network

Enable audit logging for every DHCP server on your networkEnable audit logging for every DHCP server on your network

Regularly check and monitor audit log filesRegularly check and monitor audit log files

Use 802.1X-enabled LAN switches or wireless access points to access the networkUse 802.1X-enabled LAN switches or wireless access points to access the network

Guidelines for Restricting Unauthorized, Non-Microsoft DHCP Servers from Leasing IP Addresses

To restrict an unauthorized, non-Microsoft DHCP server from leasing IP addresses:To restrict an unauthorized, non-Microsoft DHCP server from leasing IP addresses:

Ensure that unauthorized persons do not have physical or wireless access to your networkEnsure that unauthorized persons do not have physical or wireless access to your network

Microsoft DHCP ServerOnly DHCP servers running Windows 2000 or Windows Server

2003 can be authorized in Active Directory

Unauthorized, non-Microsoft DHCP ServerNon-Microsoft DHCP server software does not include the

authorization feature that is included in Windows 2000 and

Windows Server 2003

Guidelines for Restricting Who Can Administer the DHCP Service

To restrict who can administer the DHCP service:To restrict who can administer the DHCP service:

Restrict the membership of the DHCP Administrators group to the minimum number of users necessary to administer the service

Restrict the membership of the DHCP Administrators group to the minimum number of users necessary to administer the service

If there are users who need read-only access to the DHCP console, then add them to the DHCP Users group instead of the DHCP Administrators group

If there are users who need read-only access to the DHCP console, then add them to the DHCP Users group instead of the DHCP Administrators group

DHCP Users groupHave read-only DHCP console access to the server

DHCP Administrators group

Can view and modify any data about the DHCP server

Guidelines for Securing the DHCP Database

To further secure the DHCP database:To further secure the DHCP database:

Consider changing the default permissions of the DHCP folderConsider changing the default permissions of the DHCP folder

Provide only the minimum permissions required to users to enable them to perform their taskProvide only the minimum permissions required to users to enable them to perform their task

Provide Read permissions to users responsible for analyzing DHCP server log filesProvide Read permissions to users responsible for analyzing DHCP server log files

Remove Authenticated Users and Power Users to minimize access to the files in the DHCP folderRemove Authenticated Users and Power Users to minimize access to the files in the DHCP folder

Lab A: Managing and Monitoring DHCP

In this lab, you will manage and monitor DHCP