Simple Wifi question - for an expert!

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TonyS

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I have a PICMCIA card with no aerial socket which is no use in the cabin in a marina. After reading posts on this forum I now have a Netgear ME 101 wireless ethernet bridge (RJ45) connected to a Patch A0004 Poynting 8 dBi aerial.
I cannot really try it until I am on the boat for a cruise at the weekend. However I have tried the setup on the laptop in the lounge and in one direction get a strong 49% signal - so all appears to be working. All the LEDs do the right thing.
If I try then to open IE, I get "server not found". Am I right in assuming that the signal I have found in protected and the system will work OK on free internet services in marinas, such as St Peter Port, or do I have any more "setting up" to do with IP addresses etc. (which I know nothing about). Secondly is there any way of powering the bridge from the laptop.
 
Not sure that I am an expert but am responsible for a few of these things around the country..

1 you need to get an IP address from somewhere. If you have a free service in the marina and it is a router set up to serve IP addreses then when you connect to it then it will give you an IP address. If not then you will need to find out it's address before you can use it effectively. Usually they come set with addresses in the 192.168.n.n range where both n's can be variable. I would try it and see what happens first. If you end up with an address starting with 169.254 the this is the default address given to you by the operating system because it can't find an address server on the network and then you need to do some detective work. When you say free do you mean available and unsecure ??

2 I don't think there is anyway of powering your bridge from your laptop.
 
When I say free I mean that when you connect with the laptop there is an interface form from the marina and they ask for an access code. This code is given free when you pay for your stay - if you ask for it! The connection worked at 54Mbits/sec but only if I sat in the freezing cockpit on a berth close to the aerial. Hense the need for a more powerful aerial.
 
Not too familiar with your bridge but I expect you have two devices on the IP network, the marina will give you an addres via DHCP which you will have to use in order to connect to their network, so you need another IP number for your PC that you make up your self (192.168 etc). I expect your bridge will have support NAT (network address translation) in order for you to use a seperate IP network (even if it is just one PC)

I could be wrong though and I'm not an expert on WiFi. I have to stick the PC on the coach roof to get a signal, hence I use the GPRS on my phone.
 
I have checked out the manual for your device and there is a part of the setup process which allows you to enter an IP address if required. However I would suggest that you go with the standard settings (obtain an IP address automatically) to start with and see how it goes the service should issue you with an IP as part of the connection process.
 
I am afraid that bridges do not do network address translation (NAT) they simply pass IP traffic through hence all the network devices need to be on the same subnet.

Routers do NAT and "route" traffic across different subnets.

This can get a little tricky but it is all eminently solvable once the network topology is understood hence the suggestion to try it and see first.
 
""The bridge has an ethernet cable which plugs directly into the laptop""

In which case it should not be a problem and the bridge should pass your DHCP request through to the server and it should all be OK..

You need to turn on the bridge first and ensure it lights up as per the manual and then plug your laptop into it and it will then pass through the DHCP request.
 
Having given it a little more thought, I doubt you will be able to bridge someone elses network, you'd need to be able to put the log on name and password in to your bridge.

There must be a company somewhere that make an PD adapter with an aerial as I expect it is a very common problem.
 
Yeah - the trouble is lots of the terminolgy is now blurred and what we think of as a "classic" bridge often does NAT etc. too.

FWIW, I found a wifi bridge (in the true, "transparent" sense) worked very well in St Peters Port as even though we were on the first pontoon as you enter Victoria marina and could see the WiFi aerial just across the entrace, we had very poor coverage and the built-in WiFi receiver in my mac couldn't reliably get a signal. The WiFi bridge worked 100% all the time (though I could tell that the upstream link from the marina's wifi device dropped out on the odd occasion).

Rick
 
I new I shouldn't have got into this.

I am going to sound a bit pedantic here bit the blurring of names does not come from the professionals.

A bridge is a bridge and a router is a router. Bridges do not do NAT.

I have read the manual of the device in question and whilst it does have an IP address assigned it will not route (and therefore translate) between 2 subnets.
Therefore I think that if it (the bridge) is the first device onto the network it will get an IP address and then the DHCP broadcast from the laptop will get a response through the bridge. Routers do not allow broadcast messages through as they are intended for the local subnet only. This is one of these things that could take hours to explain and about 2 minutes to get working if on site.
 
Is my setup the same as a "Smartbridges airbridge" but a lot cheaper. Or have I missed something. Are you saying it should work or what do I need to do please?
 
I am saying it ought to work. It will depend to some degree on the the service and the topology of the network as supplied by your marina.

When you connect directly with them from your laptop in the cockpit do you have to give them a password or anything to get access ?? If this is usually done through an Internet Explorer screen then I think you should be OK.
 
Thanks for the reply. Yes, you have to input the password given when you pay for the berth on the IE screen and then you are connected to the WWW.
There is no service here as far as I know, so I cannot test it. I believe it is also possible to connect in the same way in East Cowes marina. My son says take it in the car to an industrial estate and I will soon find if it works as most networks are open! By the way the external aerial rather than the stub aerial provided makes a huge difference.
 
Having thought about your post I may have solved my WiFi signal.

Gonna get a wireless dongle from eBay for £25 stick on a USB extention lead or hub and pop it out of the hatch, may work for you.
 
I don't know about more setting up of IP addressing but it sounds as if, despite getting a decent signal strength that you are not being allocated an IP address from the service provider that you are trying to link to. A quick test of to see if this is the case is to open up a command box, by typing the word "command" in the run box reachable from the start menu. When the box opens, type the following command:
ipconfig
You'll then get a load of data including the IP address presently being used. Of you have got a 169.n.n.n then no IP address has been allocated as this is the default IP address that the operating system will use if it can't get one using dhcp. You should have a 196.168.n.n or 81.n.n.n. If you haven't got one then you'll need to check whether you're IP stack has been set up to receive one automaticaly.
 
I doubt that a marina with WiFi access will give everyone routable public IP address - far more likely to be in the private, non-routable range .... usually 192.168.n.n ...
If you do as suggested - ipconfig from the command line and get 0.0.0.0 or 169.n.n.n then type "ipconfig /renew" as this will try and get your adapter to renew its ip address - if it takes a while it is likely to come back with an error.

Your problem is really going to be addressing the WiFi bridge (usually via a local webpage) without first getting IP addresses, that cannot be done without first conneting the bridge to the network, that cannot be done without putting in the passcode in the webpage ... that cannot (hang on - going round in circles here!!) ....

Some bridges can be connected via USB for configuration though... very handy!
 
I get exactly the same thing as you whe I use the wireless card and I have the solution.

Run the network setup wizard and follow instructions. All will work after that.

If you wish to use a mobile phone or SIM card or dial-up internet then you will need to run the network setup wizard again and then again if you want to use the wireless network.

Hope this helps


Mark
 
Guys, maybe I'm missing something important here, but in my practical experience, all you have to do is run the software that came with the wireless card you have installed in your computer. It will check out available connections, give signal strengths, connectivity etc etc.

If you have to run the network wizard each time you want to make a connection, then it's not set up correctly in the first place

If you want to chop and change between different types of connections, no need to run the wizard, just click on the connection you want, which will already be set up if you've used them before (if you haven't got desktop links, just go to 'start' 'network connections' or similar for your operating system.)

The whole point of wizard is to set up these connections, and then use them, not to re-create them everytime.
 
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