70-291: MCSE Guide to Managing a Microsoft Windows Server 2003 Network Chapter 5: Managing and Monitoring DHCP

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 2 Objectives Back up and restore DHCP databases Reconcile DHCP scopes Use the jetpack utility to repair a DHCP database View DHCP statistics Enable and interpret DHCP audit logs Configure conflict detection Bind the DHCP service to certain network cards View and interpret DHCP events in Event Viewer Troubleshoot common DHCP problems

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 3 Backing Up and Restoring DHCP Databases The DHCP Service should be reliable and have uncorrupted data Dhcp.mdb holds addressing info assigned to clients Dhcp.tmp is only present during maintenance operations J50.log and J50#####.log are transaction logs indicating changes to the DHCP database By default, the DHCP database is backed up every hour

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 4 Backing Up and Restoring DHCP Databases (continued)

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 5 Backing Up and Restoring DHCP Databases (continued)

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 6 Backing Up and Restoring DHCP Databases (continued)

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 7 Backing Up and Restoring DHCP Databases (continued)

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 8 Maintaining the DHCP Database Over time, the DHCP database will grow in size The DHCP database may contain inconsistencies The database may need to be fixed by reconciling a scope or repairing the DHCP database itself

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 9 Reconciling Scopes The DHCP database holds summary and detailed versions of the IP address lease information Reconcile if there is a discrepancy between two versions of information Reconcile if information about leased addresses is not appearing properly Reconcile to properly show leased addresses after restoring the DHCP database

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 10 Reconciling Scopes (continued)

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 11 Repairing the DHCP Database As the DHCP database grows, the potential for corruption increases The DHCP Service creates entries in the Event Log if inconsistencies are found Repair a corrupted DHCP database by using the jetpack command-line utility

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 12 Viewing DHCP Statistics Windows Server 2003 DHCP Service automatically tracks statistics Statistics are viewable as a whole or by scope The Performance snap-in may be used to monitor DHCP statistics

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 13 Viewing DHCP Statistics (continued)

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 14 Viewing DHCP Statistics (continued)

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 15 DHCP Audit Logging DHCP audit logs keep detailed information about DHCP server activity The logs are used to troubleshoot a DHCP server They are stored in the C:\WINDOWS\system32\dhcp directory Each line contains an event ID that states the nature of the event

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 16 DHCP Audit Logging (continued)

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 17 DHCP Audit Logging (continued)

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 18 DHCP Audit Logging (continued)

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 19 Conflict Detection Using DHCP does not prevent static IP configuration A DHCP server may hand out an IP address that was already statically assigned Conflict detection prevents a DHCP server from creating IP address conflicts A DHCP server pings an IP address before it is leased to a client computer

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 20 Conflict Detection (continued)

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 21 Configuring DHCP Bindings You can choose which network card the DHCP Service is bound to The server only hands out IP addresses through a network card that has the DHCP Service bound

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 22 Configuring DHCP Bindings (continued)

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 23 Viewing DHCP Events in Event Viewer Summary information generated by the DHCP Service is placed in the system event log

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 24 Viewing DHCP Events in Event Viewer (continued)

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 25 DHCP Troubleshooting DHCP is a simple broadcast-based protocol that seldom has problems Problems include: All computers are unable to lease addresses A single computer is unable to lease an address Some computers have incorrect address information A single computer has incorrect address information

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 26 DHCP Troubleshooting (continued) Problems: A rogue DHCP server is leasing addresses Multiple DHCP servers are causing conflicts The DHCP server hands out addresses already used by hosts with static IP addresses A client is using an Automatic Private IP Addressing (APIPA) address

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 27 Summary The DHCP database normally resides in the C:\WINDOWS\system32\dhcp folder (can change) Reconciling scopes will synchronize scope information in the DHCP database The jetpack command-line utility may be used to repair a corrupted DHCP database You may view DHCP statistics in the DHCP snap-in or via the Performance snap-in

70-291: MCSE Guide to Managing a Microsoft Windows Server Network 28 Summary (continued) Audit logging enables you to view detailed information about the operation of the DHCP Service Conflict detection sends a ping packet before leasing an IP address to ensure that it is not in use You can configure the DHCP service binding to respond to DHCP clients on certain network cards only Troubleshooting DHCP problems is a valuable skill when implementing Windows Server 2003