Ytdyklly

Context: I am trying to set up a WiFi hotspot on a Raspberry Pi by bridging my ethernet connection.

Question: How do I disable AP isolation or client isolation?

Pre-work: Here is what I have done yet.

1. 
   

   Install the following modules.

   
   
   

   apt-get install hostapd bridge-utils
   
   

   
   


2. 
   

   Stop hostapd service.

   
   
   

   systemctl stop hostapd
   
   

   
   


3. 
   

   Prevent eth0/wlan0 ports from being allocated by DHCP.

   
   
   

   vi /etc/dhcpcd.conf
   
   

   
   


4. 
   

   Add the following lines towards the end of the file, but above any interface blocks.

   
   
   

   denyinterfaces wlan0
   
   denyinterfaces eth0
   
   

   
   


5. 
   

   Add the bridge.

   
   
   

   brctl addbr br0
   
   

   
   


6. 
   

   Connect eth0 to br0.

   
   
   

   brctl addif br0 eth0
   
   

   
   


7. 
   

   Add to interfaces.

   
   
   

   vi /etc/network/interfaces
   
   auto br0
   
   iface br0 inet manual
   
   bridge_ports eth0 wlan0
   
   

   
   


8. 
   

   Configure access point.

   
   
   

   vi /etc/hostapd/hostapd.conf
   
   interface=wlan0
   
   ssid=wifi-ssid
   
   hw_mode=g
   
   channel=7
   
   wmm_enabled=0
   
   macaddr_acl=0
   
   auth_algs=1
   
   ignore_broadcast_ssid=0
   
   wpa=2
   
   wpa_passphrase=passphrase
   
   wpa_key_mgmt=WPA-PSK
   
   wpa_pairwise=TKIP
   
   rsn_pairwise=CCMP
   
   

   
   


9. 
   

   Point system to use this file.

   
   
   

   vi /etc/default/hostapd
   
   DAEMON_CONF="/etc/hostapd/hostapd.conf"
   
   

   
   


10. 
    

    Reboot

    
    
    

    systemctl start hostapd
    
    reboot
    
    

    
    

Looking at hostapd.conf, it says

# Client isolation can be used to prevent low-level bridging of frames between

# associated stations in the BSS. By default, this bridging is allowed.

#ap_isolate=1

So client isolation (WLAN clients on the same AP can talk to each other) is disabled by default. Unless your built of hostapd has it enabled by default, clients should be able to talk to each other. If that is the case, enable it in the config file.

How did you determine that WLAN clients can't talk to each other, and client isolation is enabled? Have two WLAN clients ping each other?

In case your question is not about client isolation, but about the bridge between eth0 and wlan0 not working: Again, how did you test that it doesn't work? Have a host on LAN and a host on WLAN ping each other? Did you check the IP configuration on each of those hosts? How do the hosts get their IP addresses (from which DHCP server? Or static?) Did you check routes? You can debug with tcpdump -ni interface_name in a terminal window for each important interface, and see where your packets get stuck.

To actually isolate LAN from WLAN one usually uses ebtables rules, and it's unlikely you accidentally inserted the correct ones... So pretty sure something in your setup is just not working.