For a school project I'm trying to figure out how to create a safe network for IoT devices using a rpi.
To achieve that I want to use basic things that are available on raspbian like iptables and avahi. I did look into things like firewall on a bridge within the same subnet, but that didn't work out. I do think I have something possible over here but I just can't figure it out...
Here is a scheme from my current setup: https://prnt.sc/26i3vnt
Right now I have set up a raspberry-pi 3 with a bridge from wlan0 (which is connected to my home network 192.168.1.0/24) to eth0 which has it's own IoT subnet (10.1.1.0/24). Then I did connect an access point to be able to connect a chromecast to the IoT subnet.
To create that bridge I used the script from option 2: https://willhaley.com/blog/raspberry-pi-wifi-ethernet-bridge/
Now I'm able to connect devices to the IoT subnet, on which I receive DHCP and am able to surf the interwebs from.
What I did next is avahi, an mDNS service to be able to detect the Chromecast from the 192.168.1.0/24 network, it should be as simple as setting "enable-reflector" to "yes" in the file
But that isn't working for me.
An important detail; Right now I'm not able to ping from 192.168.1.0/24 to 10.1.1.0/24 or vice versa.
Been looking at this for hours and hours, any help, tips, opinions or ideas are welcome!