But.. What if you want to bridge the ethernet and wifi interfaces and let your existing router handle DHCP and routing?
Well here's my solution taken from a few sources.
Update stuff.
sudo apt-get update && sudo apt-get upgrade -y && sudo apt-get dist-upgrade && sudo reboot now
Set the wifi locale
sudo raspi-config
Install hostapd for the access point
sudo apt-get install hostapd bridge-utils
sudo systemctl stop hostapd
Create a config file for the access point
#sudo nano /etc/hostapd/hostapd.conf interface=wlan0 bridge=br0 driver=nl80211 ssid=ras hw_mode=g channel=1 wmm_enabled=0 macaddr_acl=0 auth_algs=1 ignore_broadcast_ssid=0 wpa=2 wpa_passphrase=changeme wpa_key_mgmt=WPA-PSK wpa_pairwise=TKIP rsn_pairwise=CCMP
Have a test
sudo /usr/sbin/hostapd /etc/hostapd/hostapd.conf
Tell hostapd which config file to user
#sudo nano /etc/default/hostapd DAEMON_CONF="/etc/hostapd/hostapd.conf"
Enable the service
sudo systemctl unmask hostapd sudo systemctl enable hostapd sudo systemctl start hostapd
Stop dhcp from allocating eth0 and wlan0 IP addresses
#sudo nano /etc/dhcpcd.conf denyinterfaces eth0 wlan0
Add the bridge between the interfaces and let it have a dhcp address
#sudo nano /etc/network/interfaces auto br0 iface br0 inet dhcp bridge_ports eth0 wlan0
Add a bridge
sudo brctl addbr br0
Reboot -
sudo reboot
You should have br0 on dhcp now
Extras
Add these lines to the /boot/config.txt to disable the onboard hardware
dtoverlay=disable-wifi dtoverlay=disable-bt
Refs
https://github.com/billz/raspap-webgui/blob/master/includes/hostapd.php
https://www.raspberrypi.org/forums/viewtopic.php?t=193770 http://www.d3noob.org/2018/12/raspberry-pi-setup-as-bridged-wifi.html?m=1 https://davidtavarez.github.io/2018/re4son_kernel_raspberry_pi/
https://elinux.org/RPI-Wireless-Hotspot
https://github.com/raspberrypi/linux/issues/2619
https://github.com/igorpecovnik/hostapd/issues/1
https://github.com/gnab/rtl8812au/issues/6
https://github.com/aircrack-ng/rtl8812au/issues/408
5G config
ssid=raspi wpa_passphrase=changeme bridge=br0 country_code=US interface=wlan0 driver=nl80211 wpa=2 wpa_key_mgmt=WPA-PSK rsn_pairwise=CCMP macaddr_acl=0 logger_syslog=0 logger_syslog_level=4 logger_stdout=-1 logger_stdout_level=0 hw_mode=a wmm_enabled=1 # N ieee80211n=1 require_ht=1 ht_capab=[MAX-AMSDU-3839][HT40+][SHORT-GI-20][SHORT-GI-40][DSSS_CCK-40] # AC ieee80211ac=1 require_vht=1 ieee80211d=0 ieee80211h=0 vht_capab=[MAX-AMSDU-3839][SHORT-GI-80] vht_oper_chwidth=1 channel=36 vht_oper_centr_freq_seg0_idx=42
