1. Module 3: Managing and Monitoring Dynamic Host Configuration Protocol (DHCP)

2. Overview Managing a DHCP Database Monitoring DHCP
Applying Security Guidelines for DHCP

3. 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

4. Overview of Managing DHCP
The DHCP service needs to be managed to reflect changes in the network and the DHCP server
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

5. 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 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
Res*.log
J50.chk

6. How a DHCP Database Is Backed Up and Restored
DHCP Server
DHCP
Offline Storage
Restore
Back up
Restore
Back up
In the event that the server hardware fails, the administrator can restore only from the offline storage location
The administrator moves a copy of the backed up DHCP database to an offline storage location
If the original database is unable to load, the DHCP service automatically restores from the backup directory on the local drive
The DHCP service automatically backs up the DHCP database to the backup directory on the local drive

7. How to Back Up and Restore a DHCP Database
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

8. How a DHCP Database Is Reconciled
Detailed IP address lease information
Compares information to find inconsistencies
Registry
Summary IP address lease information
Reconciles inconsistencies in the DHCP database
DHCP Server
Example
Summary information
Detailed information
Reconciled DHCP database
Client has IP address
IP address
is available
Create an active lease entry

9. How to Reconcile a DHCP Database
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

10. Practice: Managing a DHCP Database
In this practice, you will manage a DHCP database

11. 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

12. Overview of Monitoring DHCP
Why monitor DHCP?
The DHCP environment is dynamic
Increased DHCP server performance
Provides the ability to plan for current and future needs
DHCP data includes:
DHCP statistics
DHCP events
DHCP performance data

13. 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

14. What Are DHCP Statistics?
DHCP Server
DHCP statistics represent statistics collected at either the server level or scope level since the DHCP service was last started

15. How to View DHCP Statistics
Your instructor will demonstrate how to:
Enable DHCP statistics to automatically refresh
View DHCP server statistics
View DHCP scope statistics

16. 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

17. How DHCP Audit Logging Works
Audit logging is the daily collection of DHCP server events into log files.
DHCP server closes the existing log and moves to the log file for the next day of the week
DHCP server writes a
header message in the
audit log, indicating
that logging has started
12:00 am
3. DHCP closes
daily audit log
1. DHCP opens
daily audit log
DHCPSrvLog-Tue.Log
2. DHCP performs
disk checks
DHCPSrvLog-Mon.Log
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

18. How to Monitor DHCP Server Performance by Using the DHCP Audit Log
Your instructor will demonstrate how to:
Enable and configure DHCP audit logging
View the DHCP audit log

19. Guidelines for Monitoring DHCP Server Performance
Create 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
Review DHCP server counters to look for significant drops or increases that indicate a change in DHCP traffic

20. Common Performance Counters for Monitoring DHCP Server Performance
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
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

21. 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
Use scripts with your alerts

22. Practice: Monitoring DHCP
In this practice, you will monitor DHCP

23. 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

24. Guidelines for Restricting 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 network
Enable audit logging for every DHCP server on your network
Regularly check and monitor audit log files
Use 802.1X-enabled LAN switches or wireless access points to access the network

25. Guidelines for Restricting Unauthorized, Non-Microsoft DHCP Servers 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 network
Microsoft DHCP Server
Only DHCP servers running Windows 2000 or Windows Server 2003 can be authorized in Active Directory
Unauthorized, non-Microsoft DHCP Server
Non-Microsoft DHCP server software does not include the authorization feature that is included in Windows 2000 and Windows Server 2003

26. Guidelines for Restricting 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
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 group
Have read-only DHCP console access to the server
DHCP Administrators group
Can view and modify any data about the DHCP server

27. Guidelines for Securing the DHCP Database
To further secure the DHCP database:
Consider changing the default permissions of the DHCP folder
Provide 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 files
Remove Authenticated Users and Power Users to minimize access to the files in the DHCP folder

28. Lab A: Managing and Monitoring DHCP
In this lab, you will manage and monitor DHCP