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Topic: Arduino Network causing severe battery drain on WiFi connected devices. (Read 3 times) previous topic - next topic

pylon

It's not the subnet that holds back the ARPs, it a different segment, so you need a router between the two segments. Depending on the router you're using for your WLAN you may have the possibility to separate the WLAN and LAN part of your network. For example if you're using OpenWRT on your WLAN router, this is possible.

vincentmckenzie

Thanks for the clarification - much appreciated. I was sort of naively hoping that putting it on another subnet would be enough as some broadcasts I see on Wire Shark are sent to 192.168.0.255 and I also hoped the router would segment the subnets itself given everything on the other subnet is all coming off one port on the router.

If this can't be fixed in the Ethernet code (or mine), then I'll look at getting an additional router. The one I have doesn't have an OpenWRT port (yet).

I'm hoping that when I have time to trawl through the network libraries I'll be able to find a place where I can add entries to an ARP table.

pylon

ARP isn't done on the Arduino processor but by the WizNet5100 itself, so you cannot change the Ethernet library to work around that.

Have you checked your routers configuration if there isn't an option to separate the wireless from the fixed network? Some of the routers (even without an Open Source firmware) offer such an option.

vincentmckenzie

I'll not check the Ethernet library then :) Thanks for saving me a lot of time there.

It's a shame there's no function to add an IP address with its MAC too so it never has to try and get that info from the network. Obviously on Windows or Linux you can manually add a static ARP entry with the arp command.

On my router I can "isolate" any of its WiFi networks, which means all devices using that SSID have no access to the LAN and can only access the internet. This does work and would be a good solution but I need to access my LAN from wireless devices (e.g. VNC/Remote Desktop from my phone to PC).

Unless there's some undocumented arp command, it looks like I'll need a cheap router. There's another device that is (optionally) connected to my network that does this every second (another embedded system) so that sweetens the situation a bit.

SurferTim

Just because I am curious (and use a lot of routers) what make/model router do you have now?

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