There is a table in the networking software called the ROUTE table. When you get the first TCP connection
(let's assume its the wired connection), an entry is made into it so transmissions from the PC go to your ISP - - this is called the DEFAULT route. Using your Ethernet adapter Local Area Connection data
Code:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Atheros AR8152 PCI-E Fast Ethernet Controller
Physical Address. . . . . . . . . : B8-AC-6F-78-C9-B0
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::fc83:b89d:b3aa:e73f%11(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.0.3(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : Sunday, November 18, 2012 5:16:30 PM
Lease Expires . . . . . . . . . . : Sunday, November 18, 2012 6:50:20 PM
[B]Default Gateway . . . . . . . . . : 192.168.0.1[/B]
your route table would then look like
Code:
Active Routes:
Network Destination Netmask Gateway Interface Metric
=>Default=> 0.0.0.0 0.0.0.0 192.168.0.1 192.168.0.3 20
127.0.0.0 255.0.0.0 On-link 127.0.0.1 306
127.0.0.1 255.255.255.255 On-link 127.0.0.1 306
127.255.255.255 255.255.255.255 On-link 127.0.0.1 306
192.168.0.0 255.255.255.0 On-link 192.168.0.3 276
192.168.0.3 255.255.255.255 On-link 192.168.0.3 276
192.168.0.255 255.255.255.255 On-link 192.168.0.3 276
The Gateway is always the upstream router and to send anything to it, the NIC address of the PC is used (192.168.0.3). The Destination/Masks of 0.0.0.0 is what makes line one the default and the TCP software acts
as if "if I don't know where it goes, send it to the default".
Now if you get another connection (like trying to a the WiFi even though the LAN is already connected),
you ONLY add one line to the existing table, like
Code:
192.168.1.117 255.255.255.0 onlink 192.168.1.117
The WiFi connection will not send any requests outbound but the DEFAULT route will still manage all TCP traffic though the Lan connection.
CONCLUSION: Don't connect both wired and wireless at the same time - - One or the Other, NEVER BOTH