So are the two internet connections in the same house then?
When you connect to 2 networks at the same time, the one that is used for internet data is the one that the OS thinks is the "default gateway". In Windows at least, a lower metric is often given to the wired networks adapter than for the wireless adapter so the default gateway tends to be on the interface with the lower metric.
You can change the default gateway using the route command or you can try to override the metric on one or other adapter.
But it will be easier to disconnect from the BT router by disconnecting the ethernet cable at his PC.
Note that if your brother wants to be attached to both networks at the same time
(e.g. to access locally shared stuff) they need to be numbered differently so if they both use 192.168.x.* then the "x" needs to be different on the 2 networks by changing the settings on one or other router.
Example routing commands (you need to open Command Prompt as an administrator - can right click the item in the Start Menu) where you replace gateway-as-bebox
with the IP address of the BeBox:
route change 0.0.0.0 mask 0.0.0.0 gateway-as-bebox
If it doesn't let you change the default route this way, you can delete the default route then add the BeBox:
route delete 0.0.0.0 mask 0.0.0.0
route add 0.0.0.0 mask 0.0.0.0 gateway-as-bebox
if you want these to be persistent, instead of route ...
use route -p ...
Note that we made no reference to the wired or wireless adapter - this is intentional - the routing table determines which adapter to use by the IP addresses hence why the networks need to be numbered differently. This also means your brother could connect an ethernet cable to the BT box and wirelessly to the BeBox and the same route commands apply.
prompt $P - Invalid drive specification - Abort, Retry, Fail? $G
prlzx on n e w n e t: ADSL2+ / 21CN at 2.5Mbps / 800k
Edited by prlzx (Sun 13-May-12 18:14:15)