Chapter Nineteen Troubleshooting the Network

Objectives To learn a systematic troubleshooting method To examine some basic necessities for troubleshooting To examine some common OS problems and their solutions

The Basic Troubleshooting Tools Boot diskettes for different OSs A recovery CD for the 32-bit OSs Some basic diagnostic utilities A toolkit A basic clue about what you’re doing

Creating a Boot Diskette in WIN9x Have one blank formatted high-density 3.5” floppy diskette. Have the WIN9x Installation CD. Click Start>Settings>Control Panel. Double-click on Add/Remove Programs. Click Create Disk Button. Follow the yellow brick road.

Key Files of the WIN9x Boot Disk –IO.SYS: –MSDOS.SYS –DRVSPACE.BIN –CONFIG.SYS –HIMEM.SYS –COMMAND.COM –AUTOEXEC.BAT –OAKCDROM.SYS –RAMDRIVE.SYS –EXTRACT.EXE –FDISK.EXE –SYS.COM –FORMAT.COM:

Installation Diskette Set for NT Have three blank, formatted high-density 3.5” diskettes and the installation CD. On the CD, browse to the i386 directory. Type WINNT /OX and follow the instructions.

Installation Diskette Set for WIN2K Have three blank, formatted high-density 3.5” diskettes and the Installation CD. On the CD, browse to the BOOTDISK directory. Type MAKEBOOT at the command prompt. Follow the yellow brick road.

Key Files for Booting NT, 2K, or XP NTLDR NTDETECT.COM BOOT.INI NTBOOTDD.SYS OSLOADER.EXE HAL.DLL

Creating an ERD in WINNT, 2K, or XP From the command prompt or from the Run line, type RDISK.EXE. Insert disk and sit back. Any time device drivers are changed or new users are added, a new ERD should be made.

When the System Fails to Boot Invalid boot disk Inaccessible boot device (or boot device not available) I/O error reading Drive C: Missing NTLDR Bad or missing command interpreter

Possible Boot Failure Solutions Check BOOT.INI –Are we pointing to the right drive? Are you using a third party disk controller? –Try reinstalling the drivers and check cables. Is the disk recognized by the system? –Run setup and see if the CMOS sees it.

More Boot Errors Error in CONFIG.SYS line XX HIMEM.SYS not loaded Missing or corrupt HIMEM.SYS Device/service has failed to start

Solutions to These Problems Rename CONFIG.SYS to CONFIG.BAK and reboot. –Windows does not require these. –If the machine boots fine now, look for errors in CONFIG.SYS. Do the same with AUTOEXEC.BAT.

Advanced Startup Options 1.Normal 2.Logged (\BOOTLOG.TXT, 3.Safe mode 4.Step-by-step confirmation 5.Command prompt only 6.Safe mode command prompt only

Normal Uh, gee, Mom. What’s that? Sometimes after an unexpected shutdown, you’ll get the advanced start menu by default. –You know you kicked the power cord out by accident, so there’s no reason to go into a different mode.

Logged As the machine boots the next time around a text file is generated of each driver and service that attempts to load. The BOOTLOG.TXT file in the root directory will tell you what services started and what ones didn’t.

Safe Mode It is a technician’s best friend. It only loads a basic set of Windows drivers. Problematic drivers can be removed and/or reloaded and the machine restarted. Ghosts in the machine can be sorted out from here.

Step by Step Confirmation Each line in CONFIG.SYS and AUTOEXEC.BAT is listed and you choose whether to load them or not. Windows ignores these lines anyway, but go ahead and have fun if you like.

Command Prompt Only Loads only a basic DOS prompt without any superfluous drivers used only in graphical mode Good for running old DOS programs that don’t get along with Windows Good for troubleshooting file system issues

Command Prompt Safe Mode If this is the only way your system boots, it will probably be necessary to reinstall Windows. –BUT -- you can access the drives and files from here and back up critical files.

Troubleshooting Network Issues Blinky lights –Lights on NICs, hubs, and switches indicate connectivity. –Green is good; amber means they see each other, but can’t talk. –No light is REAL bad.

Ping Successfully pinging an IP address, but failure to ping a computer name means DNS isn’t working. Failure to ping an IP address (assuming connectivity) means TCP/IP isn’t working. –Usually a configuration issue Failure to ping means the NIC isn’t working.

Device Manager A yellow exclamation point next to the NIC indicates the device is recognized but the driver or configuration is invalid. A red X means that a driver is loaded for that device but Windows doesn’t see it.

IPCONFIG If the IP address reads , the NIC is not configured at all. If the IP address reads 169.x.x.x, the NIC is working, and is configured for DHCP, but a DHCP server isn’t being found.