Table 9-6 Troubleshooting Tools for Wired and Wireless Networks
Tool | How Used |
Cable tester | Tests network cables for proper wiring and operation |
Loopback plug | Tests network port or cable connected to network port |
Punch-down tool | Attaches TP cables to an RJ-45 jack |
Toner probe (also known as tone | Tests individual wire pair; more widely used with |
and probe) | phone lines than network cables |
Wire stripper | Removes outer jacket from TP cables |
Crimper (also known as “crimping | Attaches RJ-11 or RJ-45 plug to paired TP cables; |
tool”) | different crimping dies are needed for RJ-11 and |
RJ-45 plugs | |
Ping* | Tests connectivity with another host on your network |
or a remote IP address or website | |
IPConfig* | Displays IP address, subnet mask, gateway, DNS |
servers, releases and renews IP address, depending | |
upon options used with program | |
Tracert* | Traces route from your system to the specified IP |
address or website; checks up to 30 hops by default | |
Netstat* | Displays TCP connections in use; can also display |
UDP connections and Ethernet stats, depending upon | |
selected options | |
Nbtstat* | Displays services running on your computer or a |
remote computer | |
Net* | Displays and uses network resources |
Wireless locator | Detects wireless networks |
*Windows command-line program; open command prompt to use this program
Use Table 9-7 to look up typical symptoms, problems, and solutions for wired and wireless net-work issues.
Chapter 9: Troubleshooting 183 | |||
Table 9-7 Network Symptoms, Problems, and Solutions | |||
Symptom | Possible | Items to Check | Typical Solution |
Cause | |||
No connectivity | Wireless: Not | Check the wireless | Turn on the wireless network |
connected to | connection. | adapter (laptop) or remove/ | |
network. | reinstall the adapter with | ||
Device Manager (laptop/ | |||
desktop). | |||
Open the wireless connection | |||
manager and provide creden- | |||
tials as requested to connect. | |||
Wired: | Check the Ethernet | Replace the cable if defective. | |
Disconnected or | cable. | ||
defective net- | |||
work cable. | |||
No valid IP | Check the IP | Run IPConfig to check IP | |
address. | address. | address. If IP address shows | |
as 0.0.0.0, use IPConfig / | |||
releaseandIPConfig /renew | |||
to get new address from the | |||
DHCP server. | |||
If you cannot renew the IP | |||
address, reset the router. | |||
Router may be | Check the router. | Reset the Internet access | |
out of service. | device, and then reset the | ||
router. | |||
APIPA address | Can’t connect to | Check router. | Reset the Internet access |
DHCP server. | device, and then reset the | ||
router. | |||
Limited con- | DNS server | Check the DNS | If the DNS server has the |
nectivity | may be out of | server in use with | same address as the gateway, |
service. | IPConfig. | reset the Internet access | |
device, and then the reset | |||
router. | |||
Local connec- | Router may be | Check the IP | If the device has IP address in |
tivity | out of service. | address with | 169.254.x.x range, local con- |
IPConfig. | nectivity only is possible. |
Reset the Internet access device, then reset the router.
184 CompTIA A+ Quick Reference
Table 9-7 Continued