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
        ↓
Are the router’s power & link-lights lit?
Yes  or  No
↓        
Possible Solutions
A. Misconfigured router. The router may be configured with the wrong IP addresses for its interfaces. Configure them properly.
B. Rogue DHCP server giving out wrong IP addresses. If addresses are from DHCP, verify that they are from the correct IP network for this subnet. If not, there could be a rogue DHCP server dishing out incorrect addresses. Find it and shut it down.
C. DHCP server is giving out wrong default gateway address. Properly configure DHCP server’s scope to provide correct default gateway router IP address.
D. Router is on a different switch/hub, and that switch/hub is down or locked-up. Power-on or reset switch/hub.
Problem Solved?
Document Your Solution
FINISHED

Click here for a graphical version of this flowchart.