Another good reason to keep a POTS line and modem around:


http://lifehacker.com/5746046/how-to-foil-a-nationwide-internet-shutdown

Satellite phones and ham radio work, too.

So, does ad-hoc Wifi networks actually work in these cases? where there's ONE link to the outside and no infrastructure.

From my bedroom I can pick up (though not log on to) the WiFi network of seven neighbors. Would it be possible to set up a neighborhood-wide WiFi network using everyone's WiFi routers? We couldn't talk to the outside world but could we send messages and information between houses in this manner? That in it's own way would be a good safety net.

I can envision a local HAM posting news updates, a nurse or doctor being on call to respond to a medical emergency, someone passing files to people on treating water, etc...

-Blast

Yes Blast, you can set up a neighborhood wi-fi intranet.
Altho, from a security viewpoint this is not advisable.

And as stated, the only info you would have is what you already have on one of the computers. Still, would be quick and easy to pass info. Check on the web for info on how to do it, would be too long to post here, and I'm lazy.

If you want to be "really secure" see what the cost of running underground co-ax would be. I'm thinking probably not cost-effective in the long run, but a thought.

Chances are you wouldn't be able to set up an ad-hoc WiFi Intranet as most likely your neighbors are using completely different and incompatible router models, which probably don't have the facility to provide wireless bridging functionality.

http://compnetworking.about.com/cs/wirelessproducts/f/apbridgingmode.htm

Typically you would need to be using the same router manufacturer which have the a wireless bridging facility.

To bridge the individual networks wirelessly (assumming you can get the basic network working) requires some network design skills and agreements to cater for everyones requirements and to provide intranet communications requires some knowledge in setting up dedicated intranet email, webpage and DNS servers to share information on the local Intranet.

Typically a wireless bridge setup configuration is shown here;

http://www.draytek.com/user/SupportAppnotesDetail.php?ID=117

Then there is the issue of security.

There are two ways to do this: Create an ad-hoc network of end-nodes (not wireless APs or routers). This works out of the box with most laptops but isn't easy to do well on a neighborhood scale. The devices move and most of them have crummy antennas.

The better way is to set up "mesh" wireless via APs or routers. Unfortunately almost no consumer-grade gear is capable of doing this out of the box. Some consumer-grade gear can be modified in software to support mesh wireless, and this can work well. It requires compatible hardware and either a dedicated hobbyist or a professional to set up. It may also require an investment in antennas. You could conceivably set up IRLP or some other packets-over-HAM-radio technology to permit people to email health and welfare information to the outside world.



Setting up an FRS or CB radio watch is a lot easier, I'd think.

That's actually what we did during hurricane Ike. Rather than continue to hijack this thread I'm going to start another.

-Blast

Why? Can you be more specific?

You can use your old dial-up connections or ham radio like they are in Egypt. In Egypt they call out to other countries dial up numbers.....

MrEnergyCzar