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