Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have multiple 3G data Cards as well as a wired connection to the Internet. I can connect each of them separately and access the internet. Is there any way i can aggregate the bandwidth of these cards to enjoy the combined speed? What i mean is simultaneously plugging in all the cards and getting the sum total of the bandwidth.

share|improve this question
up vote 5 down vote accepted

You could do this. Network Manager can do one connection per device just fine. But even with network-manager connected to multiple things, outbound traffic will only chose one gateway. You need to bridge these gateways into a virtual tunnel and use that as the gateway.

The problem is all the machinery is there (iptables, ipchains, iproute2, etc) is somewhat lower-level than network manager. You can try and follow a guide showing example configuration to split traffic over multiple gateways but network-manager might end up getting in the way.

It might not. It might work out just fine. You won't know until you've poked it ;)

share|improve this answer
imho network-manager will only get in the way when the network interfaces bounce if he uses the load balancing method from your link. my understanding of nm breaking things is the route table mangling it does when links bounce. if it doesn't remove the multiroute component when an interface goes down, you'll just get proportional packet loss. one additional note: he might want to change the weight values to map to available bandwidth more correctly. if he switched to wicd postup and postdown scripts could be added to fix the multiroute. – RobotHumans Nov 18 '10 at 13:43
+1 - this is the right solution. it just requires some tweaking – RobotHumans Nov 18 '10 at 13:44

No, you can't aggregate multiple data cards out-of-the-box.

You need to buy a device that does link aggregation(802.3ad protocol).

share|improve this answer
Link aggregation is not the right subject for this problem. LA is binding two cables going both going from A to B in order to handle more bandwidth. This problem is binding A's separate links to B and C together. – Oli Nov 18 '10 at 13:41

In my opinion you cant.Because you can not make your network manager connect to multiple lines at the same time..

share|improve this answer
I have two wireless and a wired adapter plugged in now. I can connect to three different networks just fine in network-manager. – Oli Nov 18 '10 at 13:32
ohh is it..You should get 3 ips in that case isnt it ?? – karthick87 Nov 18 '10 at 13:40
Yeah you would. – Oli Nov 18 '10 at 13:43
If my understanding of the subject is correct, i will get three separate IP's on the three interfaces ( provided i have 2 wireless and 1 wired ) but only one outbound gateway will be chosen and hence there will be no bandwidth aggregation. Am i right? so is there a consensus that i need to bridge that into a tunnel and use that as gateway. – tinhed Nov 18 '10 at 16:01

You need to "bridge" multiple connections into one. While I've never done it on Ubuntu myself, the following guides seem to have directions for it:

share|improve this answer

You can configure Linux routing to use more than one gateway easily. The more problematic part is that if one of the gateways is down, you want your machine to stop using it and start again once it's up. I have once written a script that does it (only for wireless connections). You can see torrent working and utilizing 3 different wifi internet connections here:

enter image description here

If you want to see the script to understand what commands I used see:

The first versions have just the configuration commands, the later versions stop using a connection if the gateway of that connection cannot be reached and retry after some time.

Expect newbie coding quality., I was just studying bash at that time.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.