HOWTO: Setup OpenWRT (LEDE) WiFi repeater (the right way)

openwrt_relayd_repeater.md

HOWTO: Setup OpenWRT (LEDE) WiFi repeater

First of all, you need to install relayd package:

opkg install relayd
/etc/init.d/relayd enable

Edit DHCP configuration

file: /etc/config/dhcp

Fully disable DHCP. Example:

...
config dhcp 'lan'
        option interface 'lan'
        option dhcpv6 'server'
        option ra 'server'
        option ignore '1'
        option ra_management '1'

config dhcp 'wan'
        option interface 'wan'
        option ignore '1'
...

Edit firewall configuration

file: /etc/config/firewall

Join LAN and WWAN interfances. Example:

...
config defaults
        option syn_flood '1'
        option input 'ACCEPT'
        option output 'ACCEPT'
        option forward 'REJECT'

config zone
        option name 'lan'
        option input 'ACCEPT'
        option output 'ACCEPT'
        option forward 'ACCEPT'
        option network 'lan wwan' # bridge

config zone
        option name 'wan'
        option input 'REJECT'
        option output 'ACCEPT'
        option forward 'REJECT'
        option masq '1'
        option mtu_fix '1'
        option network 'wan'

config forwarding
        option src 'lan'
        option dest 'wan'
...

Edit WiFi configuration

File: /etc/config/wireless

Setup client and AP interfaces. Example:

# Hardware config
config wifi-device 'radio1'
        option path 'pci0000:00/0000:00:00.0'
        option type 'mac80211'
        option htmode 'HT20'
        option country 'UA'   # Your country here
        option disabled '0'   # Enabled
        option channel 'auto' # Auto recommended (set chanel on main AP, if you need)
        option hwmode '11g'   # Wifi operation mode
        option txpower '17'   # Transmit power (it is recommended to leave default value)
        option macaddr 'f8:d1:11:43:8f:ef' # Mac (optional)

# Client config
config wifi-iface
        option device 'radio1'
        option network 'wwan'            # Wireless wan
        option mode 'sta'                # Client mode
        option ssid 'WEB'                # Main AP SSID
        option bssid '04:8d:38:d0:20:0a' # Main AP BSSID
        option key 'password'            # Wifi secret key
        option encryption 'psk2+ccmp'    # Main AP encryption type (WPA2-AES, recommended)

# Repeater AP
config wifi-iface
        option device 'radio1'
        option mode 'ap'              # AP mode
        option ssid 'DDWRT'           # AP name
        option encryption 'psk2+ccmp' # Encryption type (WPA2-AES, recommended)
        option key 'password'         # AP secret key
        option network 'lan'          # AP network

Edit network configuration

File: /etc/config/network

Join LAN and WWAN interfaces. Example:

# Local network config
config interface 'lan'
        option force_link '1'
        option type 'bridge'
        option proto 'static'
        option ipaddr '192.168.2.1' # Subnetwork
        option netmask '255.255.255.0'
        option gateway '192.168.1.1' # Main network
        option dns '192.168.1.1'
        option ip6assign '60'
        
        # Join WAN and LAN ports (remove WAN configuration!)
        option _orig_ifname 'eth0 wlan0-1'
        option _orig_bridge 'true'
        option ifname 'eth0 eth1' 

# WWAN (Wireless WAN) config
config interface 'wwan'
        option proto 'static'
        option ipaddr '192.168.1.2' # Repeater IP
        option netmask '255.255.255.0'
        option gateway '192.168.1.1' # Main network
        option dns '192.168.1.1'

# STA Bridge (relayd) config
config interface 'stabrige'
        option proto 'relay'
        option network 'lan wwan' # Join LAN and WWAN
        option ipaddr '192.168.1.2' # Repeater IP