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Is it possible that one computer talks to several devices with the same IP address. I would like to realize this with the following setup:

  1. one GNU/Linux box with several virtual interfaces, each is assigned a different IP address and VLAN
  2. switch where every port is in different VLAN, except port that is connected to the computer (if I remember correctly that is called a trunk port?)
  3. somehow configure my application (e.g. ping) to use the interface I want

Is my way of thinking in the right direction? Did I miss something or write totally incorrect/impossible stuff?

I cannot change the IP addresses of the devices that my computer connects to (they come from the store with this IP address and I have to configure them)

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Why cant you configure each device with a different IP? – VBwhatnow Jul 25 '12 at 10:35
Because they come preconfigured with the same IP address, and I have to configure them (IP address and some other things). So I want to make process faster for me. – v_m Jul 26 '12 at 8:47
I think your only option is to configure each device one by one. – VBwhatnow Jul 26 '12 at 8:51
It's 2012. What kind of backwards devices don't do IPv4 link-local (or IPv6 link-local) by now? – Spiff Jul 26 '12 at 9:10
Good point, I will check if the devices support autoIP, hadn't thought of that one. – v_m Jul 26 '12 at 10:33

Is it possible that one computer talks to several devices with the same IP address.


One way I can think of is to have one NAT router for each device. Then your computer talks to different IP-addresses, the NAT routers allow the traffic to reach devices with a common IP-address.

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But would not VLANs separate the network on layer 2, so I do not hved problem with routing? – v_m Jul 26 '12 at 8:07
@v_m: The difficulty is that IP intend you to use IP-addresses (not interfaces) to address other devices. I don't know how to force a specific instance of an application to use only a specific "virtual interface". Choice of network interface for outbound data is a routing question - usually handled centrally by the O/S. – RedGrittyBrick Jul 26 '12 at 9:00

"Is it possible that one computer talks to several devices with the same IP address"

Yes, it's called a multicast address. Try pinging If you are on a corporate network, chances are that multicast address is filtered. However, at home (for instance) you should receive a response from multiple devices.

Regarding the comment on link-local addresses: it would not be a good idea for your device to only be configured with a link-local address. They will not be able to talk to computers on the rest of the Internet. That is, they can only talk to things behind your router. A link-local address is a last ditch effort to establish basic communication.

I have a feeling you may know this already, but for future reference I feel it is worth making some clarification.

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