Interference between two wireless cards in one PC?

If you're on different non-overlapping channels, there will be little interference. The three non-overlapping channels are 1, 6, and 11. However, Ch 3 overlaps onto Ch 1. Therefore, I suggest you move your Ad-Hoc network to Ch 6.

The mostly likely culprit is that your route changes when connected to whatever wireless access point appears and is probably the remote gateway for the VPN. Assuming you're running some Windoze mutation, from an MSDOS window, run: route print to dump routeing table. Try to figure out where you packets are really going. If you're not sure, try running: tracert ip_address where IP_address is some address on the internet. It might show the route packets take to get through the VPN, to the internet, etc.

Also, I once threw together a wireless repeater crafted from a pair of DWL-520 PCI cards in one machine. The antennas were about 2" apart. The radios were on Ch 1 and Ch 11 for isolation. There was no obvious RF interference problems with this arrangement, although I didn't do much testing beyone moving the antennas around and using the site survey tool to check for S/N deterioration.

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Jeff Liebermann
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I am using the following configuration:

Two desktop computers communicating trough a wireless network (ad-hock) (Cards: Gigabyte GN-WPKG).

In one of the computers it is also installed another wireless card (D-link g520+) with an external antenna. This card is connecting me to the Internet (distant accesspoint)


The ad-hock (peer-to-peer) communication between my two computers seems to work fine when my Internet connection is disabled. However, when I connect to Internet trough the D-link, the ad-hock communication fails. The ad-hock is WEP encrypted on channal 3, while the external communication is trough VPN on channal 1 or 11 (depends on link quality...).

Any suggestion on wath I can do to run both networks at the same time?


Reply to
Terje Midtbø

Thank you for your answer. This evening I have done some more research, and it sems like my local peer-to-peer network goes down the moment my VPN connection is established. When close down the VPN my local network is OK again. I have tried to generate some network activity without the VPN, and it does'nt seme to influence on my local network.

Any suggestion on what I can do?


Jeff Liebermann wrote:

Reply to
Terje Midtbø

Several possibilities.

  1. Your routes change when you connect to the VPN. Run: route print before and after connecting to the VPN. See where your local packets are going. Post both results and we can help. While you're at it, kindly disclose what operating system you're using, what version, what VPN client, what version, what wireless service you're using, IP address assignments, and anything else that might seem useful.

  1. You configured your ad-hoc network to be the same as the VPN IP block. If your VPN delivers an IP address as from its IP address pool, then you should NOT use for the ad-hoc network. The is fine, but don't re-use Depending on the client and/or OS, your routing will be a mess. Run: ipconfig /all | more to see what IP addresses are assigned to which interfaces.

  1. Isolating the VPN traffic from the rest of the network is a security feature of many VPN clients. For example, the Boigo wireless client disconnects the user from anything outside the VPN address space. This is normally a good thing as it protects against client to client hacking and worm distribution. In a host spot environment, there's also no reason to connect to other nearby clients.

Methinks #3 is the most likely, especially if you're using Boingo.

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