B-2: Tcp/Ip Settings Problems - SMC Networks 2585W-G User Manual

B-2: TCP/IP Settings Problems

IEEE 802.11b/g
Stage A
Client
Computer
Fig. 58. Communication stages for a client to reach its correspondent host.
For a wireless client computer to communicate with a correspondent 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, then the AP relays this re-
quest 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 further
packets to this IP address.
As illustrated in Fig. 58, the communication path could be broken at some of the stages. The
OS-provided network diagnostic tool, ping.exe, can be employed to find out 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 com-
mand-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:
My SMC2585W-G does not respond to ping from the client computer.
Are two or more NICs installed on the client computer?
Use Windows-provided Device Manager to disable unnecessary NICs.
Is the underlying link (Ethernet or IEEE 802.11g) established?
Make sure the Ethernet link is OK.
Make sure the wireless settings of the wireless client computer and of the
Ethernet LAN
State B
AP
43
Correspondent
Internet
Stage D
Default Gateway DNS Server
of Client Computer of Client Computer
Host