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Ok, so I have a device that sends out UDP data stream to a Linux host. The host is connected by an ethernet cable directly to a device. Device and host have fixed pre-configured IPs

[device]<---(cable)--->[networking card in Linux host]

I would like to use a WI-FI access point and wi-fi card in Linux host as a "wireless cable extender":

[device]<---(cable)---->[wi-fi access point]<----(air)--->[wi-fi card in Linux host]

The question is, how do I set up access point and wi-fi interface in Linux for such a configuration? It seems pretty basic, but somewhat different from the typical usage scenario, so I am a bit at a loss. Can I accomplish this with standard configs on access point, or I will have to load some custom dd-wrt firmware onto access point?

Also, what sort of packet "jitter" the WI-FI bridge is likely to introduce? I.e., if the device sends a (not exceedingly large) packet every 2 milliseconds, and the signal is strong, will the host see a packet every 2ms, or there will be significant irregularity introduced by the wireless bridge?

Thanks.

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Seems off-topic for SO, but it sounds pretty straightforward.

  1. Setup the AP with DHCP.
  2. Connect the device to a LAN port (not WAN-side) and have it acquire an IP. (eg. 10.1.1.2)
  3. Connect your linux box to the AP and have it acquire an IP. (eg. 10.1.1.3)
  4. Use your linux box to communicate with the new ip (10.1.1.2).

Depending on your router and firmware, you may be able to set a static IP for a given MAC address, which might be necessary if your device doesn't support DHCP.

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  • The device has fixed IP, it can not acquire one via DHCP. Also, the Linux host must know the device's address in order to send commands to it
    – tristes_tigres
    Sep 7, 2012 at 22:30
  • The last sentence of your reply is really what I have been missing. Perhaps, delete the question as too basic?
    – tristes_tigres
    Sep 7, 2012 at 23:34
  • If it can't acquire an IP via DHCP, you'll want to setup a static IP based on the device's MAC address. You'll have to make sure that you allow the router to "give out" a range of address that includes your device's IP. If the address is not private, you'll also then need to tell your linux box that it should send queries to the device's IP to the AP as a gateway -- probably using arp.
    – jedwards
    Sep 8, 2012 at 2:05

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