Start your cmd prompt with elevated privileges.
C:\Windows\system32>
ipconfig
Windows IP Configuration
Wireless LAN adapter Wireless Network Connection:
Connection-specific DNS Suffix . :
IPv4 Address. . . . . . . . . . . : 10.1.1.62
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 10.1.1.1
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
IPv4 Address. . . . . . . . . . . : 10.1.1.54
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 10.1.1.1
Check your current route metric. "
route print"
You can see my wired connection metric is 10 where my wireless connection is 25 in the "route print" command below. You can also see my USB wireless card i put in for this test is index number 24.
C:\Windows\system32>route print
===========================================================================
Interface List
24...00 08 10 77 a3 f7 ......802.11 USB Wireless LAN Card
10...bc 5f f4 10 1f 42 ......Realtek PCIe GBE Family Controller
13...08 00 27 00 ec 15 ......VirtualBox Host-Only Ethernet Adapter
1...........................Software Loopback Interface 1
15...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter
11...00 00 00 00 00 00 00 e0 Teredo Tunneling Pseudo-Interface
16...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #2
29...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #3
===========================================================================
IPv4 Route Table
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 10.1.1.1 10.1.1.54 10
0.0.0.0 0.0.0.0 10.1.1.1 10.1.1.62 25
10.1.1.0 255.255.255.0 On-link 10.1.1.54 266
10.1.1.0 255.255.255.0 On-link 10.1.1.62 281
10.1.1.54 255.255.255.255 On-link 10.1.1.54 266
10.1.1.62 255.255.255.255 On-link 10.1.1.62 281
10.1.1.255 255.255.255.255 On-link 10.1.1.54 266
10.1.1.255 255.255.255.255 On-link 10.1.1.62 281
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
192.168.56.0 255.255.255.0 On-link 192.168.56.1 276
192.168.56.1 255.255.255.255 On-link 192.168.56.1 276
192.168.56.255 255.255.255.255 On-link 192.168.56.1 276
224.0.0.0 240.0.0.0 On-link 127.0.0.1 306
224.0.0.0 240.0.0.0 On-link 192.168.56.1 276
224.0.0.0 240.0.0.0 On-link 10.1.1.54 266
224.0.0.0 240.0.0.0 On-link 10.1.1.62 281
255.255.255.255 255.255.255.255 On-link 127.0.0.1 306
255.255.255.255 255.255.255.255 On-link 192.168.56.1 276
255.255.255.255 255.255.255.255 On-link 10.1.1.54 266
255.255.255.255 255.255.255.255 On-link 10.1.1.62 281
===========================================================================
Persistent Routes:
None
Add a route using the interface switch to your NAS.
http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/sag_tcpip_pro_addstaticroute.mspx?mfr=true
In my case the "IF" number is 24 for my "Wireless Network Connection" so the route would look like this. The /P will make the route persistent.
In this example my printer IP is 10.1.1.4. Make sure to use the 255.255.255.255 mask to show it is a host address. I would also make your NAS a static IP if you haven't already.
C:\Windows\system32>
route add 10.1.1.4 mask 255.255.255.255 10.1.1.1 metric 2 IF 24 /P
OK!
Show the routes again.
C:\Windows\system32>route print
===========================================================================
Interface List
24...00 08 10 77 a3 f7 ......802.11 USB Wireless LAN Card
10...bc 5f f4 10 1f 42 ......Realtek PCIe GBE Family Controller
13...08 00 27 00 ec 15 ......VirtualBox Host-Only Ethernet Adapter
1...........................Software Loopback Interface 1
15...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter
11...00 00 00 00 00 00 00 e0 Teredo Tunneling Pseudo-Interface
16...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #2
29...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #3
===========================================================================
IPv4 Route Table
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 10.1.1.1 10.1.1.54 10
0.0.0.0 0.0.0.0 10.1.1.1 10.1.1.62 25
10.1.1.0 255.255.255.0 On-link 10.1.1.54 266
10.1.1.0 255.255.255.0 On-link 10.1.1.62 281
10.1.1.4 255.255.255.255 10.1.1.1 10.1.1.62 27
10.1.1.54 255.255.255.255 On-link 10.1.1.54 266
10.1.1.62 255.255.255.255 On-link 10.1.1.62 281
10.1.1.255 255.255.255.255 On-link 10.1.1.54 266
10.1.1.255 255.255.255.255 On-link 10.1.1.62 281
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
192.168.56.0 255.255.255.0 On-link 192.168.56.1 276
192.168.56.1 255.255.255.255 On-link 192.168.56.1 276
192.168.56.255 255.255.255.255 On-link 192.168.56.1 276
224.0.0.0 240.0.0.0 On-link 127.0.0.1 306
224.0.0.0 240.0.0.0 On-link 192.168.56.1 276
224.0.0.0 240.0.0.0 On-link 10.1.1.54 266
224.0.0.0 240.0.0.0 On-link 10.1.1.62 281
255.255.255.255 255.255.255.255 On-link 127.0.0.1 306
255.255.255.255 255.255.255.255 On-link 192.168.56.1 276
255.255.255.255 255.255.255.255 On-link 10.1.1.54 266
255.255.255.255 255.255.255.255 On-link 10.1.1.62 281
===========================================================================
Persistent Routes:
Network Address Netmask Gateway Address Metric
10.1.1.4 255.255.255.255 10.1.1.1 25
===========================================================================
The traffic for 10.1.1.4 is now going out the 10.1.1.62 interface.
To get rid of the route run this using the ip address of the NAS:
route delete 10.1.1.4 mask 255.255.255.255