Point-to-point wireless network link question...

[Mini-Me]

Hi all. :)

I want to use two wireless network cards to establish a link between an upstairs PC and a downstairs laptop.

There is no router or switch, just a point-to-point link.

Think of it like the network crossover cables you used to be able to buy, to link two machines together without using a switch or hub - this is what I want to do.

No Internet on either box, I just need it as a wireless link.

So, assume I have both machines wireless cards all setup, and static IP's assigned to each of them, I should just be able to ping one from the other and vise versa, correct?

I will put VNC server on the upstairs box, and VNC viewer on the downstairs laptop.

Do any of you see any major problems with that idea?

[PrntRhd]

It should work, called "ad hoc wireless"

[Mini-Me]

Lovely - cheers. :)

[PrntRhd]

Which OS on the PCs?

[Mini-Me]

Windows XP SP3 on both.

[PrntRhd]

Most articles talk about setting up ad hoc networks to do ICS but that is not necessary.
http://www.home-network-help.com/ad-hoc-wireless-network.html

[azzey]

Basically just create a new network and set the type to Ad-Hoc. You can enable security if you like, and then connect the other computer to it. It's pretty simple once you do it once.

[Mini-Me]

Cool - I will try that, and get back to you. The link indicates that you don't need to enable security. With an ad-hoc arrangement, can computers with wireless ability OUTSIDE the ad-hoc network, not connect or see an ad-hoc network?

Just want to clarify the security issue - i've never setup a wireless ad-hoc before, so the only thing now is if I need WEP or WPA keys etc...

[Paul Komski]

WiFi Ad Hoc networks like this, notably in Win XP do work just fine. One little possible glitch/gotcha is that both PCs much log on to the AdHoc Network in order to communicate and you should normally use Automatically Assigned IP addresses on the PCs involved. You can assign appropriate fixed IP addresses but be careful if you bridge through to a router that is running DHCP. In such a case you should assign the same IP addresses manually in the router, with the relevant PCs identified by MAC address. In such a case use the MAC address of the underlying wifi card and not the MAC address IP address of the bridge itself.

So, just for emphasis, both the client and then any host or hosts that want to access each other must log on to the AdHoc Network even though it may remain setup on the client after rebooting the client. This troubled me for a long time until I realised that the client must also log-on to the ad hoc network that it has itself, de facto, created.

Internet Access can be made via ICS as mentioned or by bridging the ad-hoc network and a cable connection to a broadband modem/router. The latter bridge (created in Network Connections) should remain intact through reboots. Never attempt to bridge a dial-up modem or WiFi Dongle to an ad hoc network because that is a huge security hole; only share such internet connections using ICS.

For completeness one can also connect to the internet normally by wifi from the Client to the router and then connect PCs using cables and a switch (or two PCs using DCC) and then bridge the wifi to the cable NIC on the client in order to "permanently" share the internet connection.

[Mini-Me]

Thanks for all that - useful info - I will read it a few times to get it clear in my head. :p BOTH the machines I want to link, have no internet access in any way, shape, or form - they are NOT connected to another DHCP-enabled and Internet connected network either wirelessly or hard-wired. I have the cards, and will install and setup this weekend. I will post back with results, good or bad. ;)

[Paul Komski]

Networking usually either works "out of the tin" or can be a real PITA.

A couple of other gotchas to be aware of:-

1. Not all wifi cards support ad hoc networking.
2. Firewalls can interfere.
3. Remember to enable MS File Sharing if that is how your 2 PC-LAN is going to be used.

Also if you run into problems the output of ipconfig /all from both PCs can often be very revealing.

[Mini-Me]

Cheers, thanks a lot for all your help and suggestions. :)

I am using a USB Wireless network adaptor thing, and it specifically says on the box that it supports Ad-Hoc mode, so HOPEFULLY there will be no issues there.

I will keep you all posted. :)

[Mini-Me]

I've been trying for days to get this working, but I cannot.

I CAN see the 2nd machine from the 1st one's wireless connections, and CAN connect to it "Computer-to-computer Ad-Hoc network", but I cannot ping it.

I must be doing something wrong... :(

1st box IP address is 192.168.1.100, 2nd box is 192.168.1.101.

I have much more luck with hard-wired networks - perhaps I will just run the freakin' cable...

[Paul Komski]

I would let Windows assign IP addresses.

Ensure both PCs are connected to the ad hoc network. The host cannot do this automatically unless the ad hoc network is the preferred network in any list of wifi connections and even then it may be necessary to manually connect (yes the host itself) to the ad hoc network.

I reiterate. First connect the host to the network it has created and then connect the client to the network being broadcast by the host.

[Mini-Me]

I came here to report torrese55, but it's already gone. :D My hat tips to the moderators here, who so actively police the forums, keeping all that guff out. I realize the mods act on reports, but if they did not, this forum would be full of junk posts like many other forums on the net, so thanks, guys! :)

Oh, and I still have not got this link going - I will have another go next week, and see if I have any more luck. I will let you know one way or the other...

Oh and Paul: I thought you needed a DHCP server in order for Windows to obtain an IP automatically? In other words, Windows cannot assign IP addresses, but it can request one from a DHCP server(such as an ADSL router) - I will look into this a bit more in Network settings.

[Paul Komski]

Oh and Paul: I thought you needed a DHCP server in order for Windows to obtain an IP automatically? In other words, Windows cannot assign IP addresses, but it can request one from a DHCP server(such as an ADSL router)
Windows can and will assign an IP address in the range 169.254.x.x with a subnet mask of 255.255.0.0. And with two PCs directly connected by cable or a wifi ad hoc network both PCs will ensure there is no conflict after they have "shaken hands".

The range can be altered in the registry (http://support.microsoft.com/kb/230148) but that is advanced stuff.

[Mini-Me]

Hokey pokey, thanks for that info. :)