Hi all, I’ve gotten a Brother machine (DCP series) that can do wifi printing/scanning over their proprietary app. However, I’d like to lock it down from my network, because having it on the same LAN as my other devices and the ability to phone out to the internet seem like room for mischievious activities.

For context, I have OpenWRT on my router, and my clients can access the Brother using their iPrint&Scan app and AirPrint on wifi, as well as the traditional USB port. But I’m not good in networking. In my research, I drafted out the following solutions:

  1. Create a firewall rule to block the printer itself from making outbound requests. Seems simple, but I’m not sure if this can persist after IP changes or not.
  2. Create a VLAN for “IoT devices” that cannot send outbound requests to my normal VLAN nor the internet. Inspiration from this video, I’d need to manage a new SSID but it may come in handy for more IoT devices later.
  3. Hook the Brother up to a Raspberry Pi via USB, and install CUPS + SANE on the Pi. Assuming the Pi cannot “phone home” on behalf of the printer, this makes it a local-only “print+scan service” on my normal network and doesn’t require an extra VLAN.

I’d like to ask: which solution above is best for “neutering” the Brother? Or are there any alternatives/details I might’ve missed? I’m not sure if blocking outbound requests this way is enough of a security hardening for an untrusted device, and if there are any usability issues I’ve overlooked so far.

Thanks for any advice, and please share any printer/scanner setup you have in your networks as well. So hopefully I can get more inspiration!

  • rearview@lemmy.zipOPEnglish
    1·
    21 hours ago

    Hi all, thanks for all your comments and suggestions, here’s a late update:

    I went with option 2 and configured the second VLAN + Wifi with the printer on it. The process was smooth except for half a day troubleshooting why DHCP was not possible (turns out I have to manually tell dnsmasq to listen on the new interface as well…). I set up a static IP address for the printer though. Adding the machine from my other devices involve manually typing out its IP, something I hope to resolve with an avahi daemon on the router later on.

    For Android specifically, printing can be configured through its “Default Print Service” which can be found in Settings. Scanning requires a separate app, and I found ScanBridge to be exactly what I need and also FOSS. The address to type in is http://$PRINTER_IP_ADDRESS/eSCL/ (note the trailing slash). There’s also Mopria Scan, which is proprietary.

    If you use a VPN on the Android, remember to exempt the print service and scan app from the tunnel.