National Instruments WAP-3711, WAP-3701 user manual TCP/IP Settings Problems

NI WAP-3701/3711 User’s Manual Troubleshooting

TCP/IP Settings Problems

IEEE 802.11g

Ethernet LAN

Stage A State B

Correspondent

Host

Internet

Stage D

	Client	AP	Default Gateway	DNS Server
	Computer		of Client Computer	of Client Computer
		Communication stages for a client to reach its correspondent host
	For a wireless client computer to communicate with a host on the Internet by the host’s domain
	name (e.g., http://www.wi-fi.com),it first sends a DNS request to a DNS server on the Internet.
	The DNS request travels first to the AP, and then the AP relays this request to the default gateway
	of the client computer. Finally, this request is forwarded by the gateway to the DNS server on the
	Internet. The DNS reply issued by the DNS server is transmitted back to the client computer
	following a reverse path. When the client computer receives the DNS reply, it knows the IP
	address of the correspondent host and sends additional packets to this IP address.
	As illustrated in the above figure, the communication path could be broken at some of the stages.
	The OS-provided network diagnostic tool, ping.exe, can be employed to determine TCP/IP-related
	communication problems.
NOTE	If two or more NICs are installed and operating on a client computer, TCP/IP may not work

properly due to incorrect entries in the routing table. Use the OS-provided command-line network tool, route.exe, to add or delete entries from the routing table. Or, use Windows-provided Device Manager to disable unnecessary NICs.

Solve the following problems in order:

The AP does not respond to ping from the client computer.

yAre two or more NICs installed on the client computer?

¾Use the OS-provided command-line network tool, route.exe, to modify the contents of the routing table.

¾Use Windows-provided Device Manager to disable unnecessary NICs.

yIs the underlying link (Ethernet or IEEE 802.11g) established?

¾Make sure the Ethernet link is OK.

B-2