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I have 2 interfaces - Wlan0 and Eth0, and both of them have separate internet lines - X & Y ISP. I want some applications to use WLAN and some to use ETH to send/receive traffic. Where can I bind different applications on different networks? I can set priority or can define 2 proxy and then bind applications on different proxy. Any scripts, apps or network configuration solutions available? And, this is not related to Source Port, Destination Port, Protocol. Let me know if there is anything specific to Application binding.

Operating Systems: Ubuntu/RedHat/*nix Application Requirements: I have Pen Test Apps like hping, nmap, nessus etc. which I want to utilize ISP X, and my normal browsing needs like Mozilla, Evolution Email Client, IM should be on ISP Y. More Information: This surely is not possible at router levels, or even through routing commands, IPchains, IPtables as I don't think they utilize the network applications in scope. At the max, they can work with Protocols but that will not help me here. Example: I am browsing my mails on yahoo/gmail etc. on Firefox/Lynx/Links via ISP Y, and it is HTTP, port 80 traffic. On the other hand, I am sending some SYN packets with hping on port 80 to for testing, which is also HTTP traffic but I want it to use ISP X. Summary: Suggest me something that can utilize application names, something intermediate to application and network layer. Or in worst cases, I will have to write a script for that, or run multiple proxy, and map applications on different proxy servers. Source port will not work, because of the randomization involved. Let me know if you need further information. Thanks

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What Operating System? What specific applications? This sort of thing can be done, but we need details or we can't help. – Chris S Jun 30 '10 at 13:16

You've given us very little information to work with here so I have to say that it depends on your setup - but typically you'd do this with via static entries in your routing table.

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I have added more information as per request. – user47178 Jul 1 '10 at 7:36

From what you are saying you can only do this from the machine itself and not say for example your router. So it needs to be the machine itself that has both the wlan and eth connections. This is because you are saying there is no network information to base the choice off of (ie source ip and source port combination). You didn't mention what operating systems or applications, but if the application is able to do this it will have an option to bind to a specific IP on the machine and that is what you need to look for.

A possibility is that you can add secondary IPs to the host and then bind to those secondary IPs via the application. Then you will have a unique source IP for that application. Then if it is the router that is multihomed you can do policy based routing and route based on the source IP.

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I have added more information as per request. – user47178 Jul 1 '10 at 7:37

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