Internet Connection "Sharing"

So err...

If for example someone has access to a wired cable modem (i.e their own 4mb line) and can see 2 other wireless unsecured networks within very close range.....would the addition of 2 wifi PCI cards to the machine increase the available bandwidth, thus make (for example) err...downloads....go faster? (assume the other 2 wifi LANs are on the internet too)

(yes, I know that connecting to an unsecured wireless network is not secure, and this is a major breach of probably a few laws, but lets just assume its not, for the moment)

The main question is, how does an OS choose which network interface to use for any given request, and can it use more than one, simultaneously, or will it just use one, full stop?



Thanks,

Mr Hypothetical.

No it doesn't work like that. With a standard OS, e.g. XP or Vista it will use a default network route.

At best you'll be able to get it to switch to another connection if the default isn't available.

Lets assume its not Windows (mainly cos thats just pants), and it is Linux.

How about you get another pc, and use your neighbours connections for downloading movies, music & (cough) whatever, and use your own for general web surfing!

you can have 2 connections to the same gateway, ie (2 wifi - one router) Or (LAN + Wifi - router)

no real point as the Lan is way faster than broadband, tho transferring large amounts of data on internal network can save a few minutes.

you can get some routers which allow you to bond 2 or more adsl lines together to get a higher speed single connection. The only problem with this is that they are really very expensive and only made by people like cisco.

As for trying to do this with a single machine that your running an os on its going to be pretty hard. I would imagine it might be possilbe to build a "router" out of an old pc and then run some softwear on it that would allow you to bond the connections then that may work but you would be basicly building a cisco box and then programming it yourself so its a matter of how much time you can be bothered to waste doing this.

Personally i wouldnt bother if its just to increase your download rate. You only need faster dl rates if your splitting your 4mb dl rate over a group of different downloads. This can be fixed by using different computers to dl the different files so instead of having 3 files on 1 pc splitting 4 mb between them you get 1 file on each of 3 pc which each have a 4mb connection.

Essentialy it is possible to do what your asking but frankly it is prohibitivly expensive/time consuming to make it work and it would be easier to just get another pc and use that to take advantage of the free unused bandwidth that just happens to be broadcast into your house.

With two potential routes the OS uses what's called a route metric to determine the best way out of the building. Actual routers will determine their routes by various ways dependent upon the discovery protocol in use but that's largely out of your hands.

So, route metrics, you can see the route preferred by typing "route print" at a DOS interface, the lower the metric the more preferred the route to that network. The one you'll be interested in is likely to be the one sat alongside the network destination of 0.0.0.0 (ie. everything else).

I can't check right now the defaults but I vaguely remember that a 54mbps wireless (ie. 802.11g) will have the same metric as a 10mbps ethernet, but a higher one than a 100mbps ethernet.

You can manually change metrics by using the route delete and route add commands. I'll dig more out when I've got time, but for the time being it's probably best to leave alone. It is possible to multiplex two connections to achieve a greater download but it would require some intermediate hardware and dependent upon said hardware may work with only certain protocols.

One way you could use it without hardware would be to assign a route metric to pipe a known network address out one route and leave the 0.0.0.0 (all other) routes going to a default. Peer to Peer traffic is effectively going to need the 0.0.0.0 route, if you played online games or something and new a range of IPs for the game servers you could give that network a metric to force it out another route. It's probably not worth bothering about

[SoulKiss]

Yes, using Linux and something like Zebra to aggregate it SHOULD be possible.

Personally I would try and route certain traffic down certain links rather than try and channel bond an ADSL and 2xADSL via WiFi as different latencies on the different connections could cause issues.

[timwilky]

You can only use mlppp bonding on ADSL circuits where the service provider supports MLPPP. so with your cable modem and 2 wireless connections. Bonding is not possible. although at a cost teaming could be done

Your only real method to use these "Available" connections would be to assign certain routes to them.

Additionally, if some numpty has left them insecure, I would also assume they are likely to still be on default networks more likely than not on the rfc1918 class "c" range of 192.168.1.0/24. So you may find that your computer doesn't like using both as they are seen to be the logical same network.

Originally Posted by fat_brstd

you can get some routers which allow you to bond 2 or more adsl lines together to get a higher speed single connection. The only problem with this is that they are really very expensive and only made by people like cisco.

I tried to change the firmware on my WRT54G to DD-WRT http://www.dd-wrt.com/dd-wrtv2/index.php but got a kick in the teeth when I found I have the only version of hardware that can't be modded.

Suspect I might ship it back and see if I can get rev 8


Anyway, lots to go on above - thanks, will get back to this post later.....