Hi, first post here, so apologies if i've popped this in the wrong place!
I need to set up a guest wifi connection for a cafe I am involved with, using my Linksys WRT1900AC(V2). I installed the LEDE firmware yesterday, which was remarkably easy, and then I followed the tutorial for OpenWRT for making a guest wlan with Luci (https://openwrt.org/docs/guide-user/network/wifi/guestwifi/guest-wlan-webinterface).
The only modification I made to this was adding a second radio on the 5GHz spectrum, so it is transmitting two identical SSIDs on different frequencies. I also went in via SSH and set the isolate option for each wireless interface, which I thought would ensure that different devices cannot talk to each other.
The networks are working fine, providing IPs in the 192.168.3.* subnet, and providing internet to clients. I cannot access the router from the wireless network, only the wired LAN, which I thought proved that the isolation worked. However, if I run "nmap 192.168.3.0/24" from my laptop on the wireless network, I can see two other devices, an iPhone and a Galaxy Tab. There are more than 2 devices connected to the network though, which are not showing up in my nmap scan.
Does anybody have any idea why this might be happening? My only current thought is that the isolation might be working between devices on each frequency, but maybe the two frequencies aren't isolated from each other?