FLINT HILLS TECHNICAL COLLEGE
Network Troubleshooting Flowchart

START
Windows Workstation Unable to Access a Network Service
Gather Clues
A. Ask Questions.
 i. What were you doing when the problem occurred?
ii. Have there been any recent changes to the network?
B. Have the customer recreate the problem while you watch.
While watching, check for obvious user errors (ID10T errors), such as Caps-Lock being on.
Do other workstations on the LAN have the same problem?
Yes  or  No
↓        
Are the switch, hub, or wireless access point's power & link-lights lit?
Yes  or  No
↓        
ping the destination by name. Successful?
Yes  or  No
        ↓
ping the destination by IP address. Successful?
Yes  or  No
        ↓
Execute: ipconfig /all
on at least two LAN workstations having the same problem. What type of IP addresses?
DHCP starting with 169.254 (APIPA)  or  DHCP IP addresses  or  Static IP addresses
                        ↓
ping Default Gateway router. Successful?
Yes  or  No
↓        
On which LAN is the destination located?
Same LAN as workstation.  or  Different LAN on the Internet.  or  Different LAN, but still on this organization's network.
↓      
tracert the destination by IP address. How far did the trace go?
Past the default gateway to other LANs, but not onto the Internet  or  Past your routers and onto the Internet, but not to the destination.  or  Not past the default gateway.
                                                                                                            ↓
Possible Solutions
A. Default gateway router’s outgoing interface is disconnected, disabled, misconfigured, or faulty. Check its link-light. Check its IP configuration. Try pinging from the router itself to the next router.
B. The switch/hub connected to the outgoing interface of the default gateway router is down or locked-up. Check the power & link-lights on that switch/hub.
C. DHCP server is giving out wrong subnet mask. This could make the workstations think the destination is on the same LAN, when it is really on a different one. Properly configure DHCP server’s scope to provide correct subnet mask.
Problem Solved?
Document Your Solution
FINISHED

Click here for a graphical version of this flowchart.