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:
- 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.
- 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.
- 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!
You must log in or # to comment.
I use a vlan for certain isolated devices that only certain personal devices have access to via their IP static addresses set in my firewall. That VLAN has no WAN access either. Sure the devices could technically talk to each other, but that doesn’t seem like a big deal since they can’t go external and only my phone and laptop and a few other trusted devices can even connect into the VLAN.
I’d just shove it on the IoT network and then set up a device based rule to block WAN. That feels the easiest for me but I’m an amateur, someone in here knows more for sure.
You’re overthinking this with 2 & 3. All you need is to block all Brother Internet traffic.
Set up a static DHCP IP for the printer in Openwrt and create firewall rules to drop all WAN packets to/from that IP.
If you want to see evidence those packets are being dropped in real time use tcpdump. When watching LAN traffic you will see the printer sending packets to the WAN interface but will never see a response directed back to the printer.
I have a Brother printer (plus cameras & TVs) and an Openwrt router set up that way and have had zero issues.
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I’ve seen in this thread:
Fewer Letters More Letters AP WiFi Access Point DHCP Dynamic Host Configuration Protocol, automates assignment of IPs when connecting to a network IoT Internet of Things for device controllers Unifi Ubiquiti WiFi hardware brand VPN Virtual Private Network
5 acronyms in this thread; the most compressed thread commented on today has 9 acronyms.
[Thread #163 for this comm, first seen 9th Nov 2026, 20:10] [FAQ] [Full list] [Contact] [Source code]
DMZ.
A DMZ is the opposite of what is needed here
No
FWIW, I have a networked Brother laser printer hard-wired to my LAN. To prevent it from calling home or pulling unfriendly firmware “upgrades”, I just configured it with a static LAN IP & subnet, but no gateway address. Been running that way for years now. So far so good…
Put it on its own VLAN or guest SSID in OpenWRT, then add a firewall rule that only lets your client subnet reach it on 631 and 9100. Block WAN for that zone completely. AirPrint discovery needs mDNS across zones, so you’ll want umdns or avahi as a reflector, and that’s the part that usually breaks. I’m building a home box that does this by default for IoT stuff. Would you want it to just work, or would you rather see the rules?
I wouldn’t recommend isolating it as it will make it a pain to print.
You don’t need their proprietary app. Brother printers support driverless printing so it will work on all major platforms
If the point of connecting it to WiFi is to make it easier to print then why would you isolate it only to make it harder to print?
If you want 100% no sneaky stuff connect it to some PC and set up a cups server on it.
I do 1.
I have DHCP but everything static gets a static IP. I need my home assistant to be able to reach both the internet and my IoT device, no idea how I’d put it in both VLANs.In a similar situation, my theory is that I can eventually configure ACLs specifically to accept connections sourced to my IOT static IP assigned devices with an implicit deny all that prevents everything else.
Though, I may be planning this all wrong, since all connections occur after my firewall, I might need to eventually set up ACLs on my smart switch.
It’s a printer, it already hellishly refuses to print or to even install correctly anywhere, it should be safe.
Exactly; it’s a printer. You better put it in a metal cage and keep a shotgun close by.
Bother tends to be a lot better than other companies in this regard. I’ve owned the same printer for years and never had an issue.
HP WiFi network printer owner here. It sits on my main network, but I’ve assigned it a fixed network IP (based on its MAC) and cut off internet access in my router. That seemed enough for me. I’m open to comments why that isn’t true. ;)
This is just my story and how I have done/am considering looking at doing it. I to have a OpenWRT firewall, I to have lived in the Apple ecosystem my whole life, but I am slowly climbing out of it.
I have a Samsung laser printer of some sort, before I got into the whole home labbing and privacy thing I just had a raspberry pi of some sort (it rotated a few times because I was attempting the adblocking with pihole off and on). When I decided privacy was the better option and I had my pihole figured out I installed CUPS on a pi zero 2, I so rarely used the thing that it was not a thought for me to look up and install SANE I just used the app and the wifi from the printer. A day came a long when I had to do the wifi suffle to do the scanning when I thought there must be a better way and installed SANE. Fun side note; I have a perimant disability and see a physio, the insurance I have wants some paper work (that so rarely changes) every three months so I just have a script that looks at my calendar so the day of my physio treatments and counts the number of times I have seen them and prints out the documents if it is time to send them! So number 2 is my suggestion for sure if you are just beginning.
I have a vLAN (10.0.69.0/24) that my homelab sits on so my printer is attached to it that way with the pi I am using for CUPS and SANE, my HAOS pi is also on that vLAN and I see HA has something it can do with the printer I have considered looking at that once or twice. Now that you have mentioned this I may just read up on it because I have issues with SANE, not sure if it is configured correctly or my printer just really does not like it but if HA can do the things I may set it up and attach it to my IoT wifi vLAN (10.66.6.0/24) which does not access the outside world but HA and my 2 personal vLANs (10.42.0.0/24 for wifi and 10.4.20.0/24 for my VPN) can do things in it. I got into numbering my vLANs with fun combos when one day I was out and about when I could not connect to my VPN because it used the same IP range or something like that.
I use static IPs for everything within their own vLAN but I do not think it would be worth my time to set up firewall rules just for it when I have other options. If it does not need to phone home for anything other than data harvasting it is either not attached to the internet like my “smartTV” or it goes onto my IoT wifi that HA can do the stuff with.
Long term, 2 is best, but 1 is a great immediate fix. Also, you should be able to assign a static IP based on the printers MAC address, which will keep the IP stable.
CUPS and USB. Dead simple, no messing with network stuff or trying to get proprietary apps working with vlans or firewalls.
It basically depends on whether you want to rely on mdns, like printing from your phone.
The standard lock down by making a vlan and subnet and then adding filtering works fine if you can reach the printer reliably by IPP or jetdirect.
Once you need to connect two disparate broadcast domains, things get weird. It was the same story for Chromecast devices for me, their functionality and convenience are based on a relatively flat network and a single broadcast domain.
