Moxa Technologies Network Hardware AWK-1100 User Manual

 

 

Default Gateway 

of Client Computer 

AP 

Stage A 

State B 

Correspondent 

Host 

Stage D 

Client 

Computer 

DNS Server 

of Client Computer 

 

For a wireless client computer to communicate with a host on the Internet by the host’s domain 
name (e.g., 

), 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: 

y

  Are two or more NICs installed on the client computer? 

¾

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

the routing table. 

¾

  Use Windows-provided Device Manager to disable unnecessary NICs. 

y

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

¾

  Make sure the Ethernet link is OK. 

¾

  Make sure the wireless settings of the wireless client computer and of the AP match.