I need a solution for the problem for the project work. We have devices, servers and clients working where each device shall have two ethernet cards installed in them. While communicating all the devices should send the data packets through the two interfaces providing the 200% data rate. If one of the card connection fails we can get 100% data rate. So I made the lab setup for testing before jumping into the project work. We have kept two servers and two clients in the network, eth0 of all the systems are going to switch1 and eth1 of all systems are going to switch2. There is no physical connection between the two switches. So while sending can I think I can use iptables to send the any data from the application layer to both the interfaces(Please correct me if Im wrong) But at the recieving end, we may or maynot get the duplicate data from the same host. I dont think at the recieving end we cant use iptables because the packet will have different ipaddress in their packets. Do we have anyother method to overcome this one. Please help me it is very urgent I need to give some solution.


3 Answers 3


What you need to do is BOND your interfaces to a single switch.. Or use a routing protocol such as STP (spanning tree protocol)

Most decent switches support this..

I would attempt to play with LACP (Link Aggregation) IEEE 802.3ad

Here is a wiki to explain


  • Thnks for the reply, I have used the bonding, but I should keep both the interfaces to two different switches. and there should not be any physical and virtual connection between the two switches. Any more ideas on this??? Nov 10, 2010 at 10:15
  • The problem you have is that you want the best of both worlds.. Speed and redundancy.. Speed = Bonding/Multiplexing Redundancy = 2 switches that arent connected.(Need STP) STP basically will shut down a link by looking at the routing tables to ensure redundancy and no loops. You cant Bond to separate switches without some serious hardware changes. I would suggest you use gigabit ethernet and STP for redundancy.. If your flooding a link through a redundant switch, buy a new NIC to bond those seperate links.. :D Depending on your type of traffic, maximising a gigabit will take some effort
    – Arenstar
    Nov 10, 2010 at 19:59

I have a similar setup for the purpose of redundancy. The simplest way to achieve this is to just bridge the two physical interfaces. Then, if one of the cables get cut, it will continue to work. Just remember to include STP even if there is no possibility of a loopback. How you do the bridging depends on the distribution that you are using.


But in your case, if both are active u r using only one and if failed u r taking another active one.. so anytime u r using only one interface but my case I have to use both the interfaces while sending the data.. Can you please correct if I can use the same briding concept.. with iptables stuff..

  • 1
    Either edit your original question, or add information as a comment next time. Nov 10, 2010 at 7:30

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