Bridged Access Point

In some cases you want to use your OpenWRT router as wireless access point only, without any routing, firewall and DNS or DHCP functionality.

This might be the case, when you already have a capable router device, but it has no adequate Wireless capability or you want improve your wireless connectivity by deploying additional access points in a larger area.

Ethernet Ports

Don’t use the WAN port!

Use any of the available LAN ports to connect your device to the LAN.

Network Configuration

The LAN network for an OpenWRT Access Point is nearly the same as for a Router. Some things to look out for:

  1. Make sure not to use the same LAN IP address as the router.

  2. Disable DHCP on all interfaces.

  3. Don’t configure the WAN interface.

  4. Set up static default routes pointing to your router.

/etc/config/network:

config interface 'lan'
    option type 'bridge'
    option ifname 'eth0'
    option _orig_ifname 'eth0 wlan0 wlan1'
    option _orig_bridge 'true'
    option proto 'static'
    option ipaddr '192.0.2.2'
    option netmask '255.255.255.0'
    option gateway '192.0.2.1'
    option broadcast '192.0.2.255'
    option dns '192.0.2.2 192.0.2.1'
    option ip6gw 'fe80::4e5e:cff:fe40:11a5'
    option ip6addr '2001:db8:c0de:10:2cb0:5dff:fe7f:2dba/64'

config interface 'wan'
    option ifname 'eth1'
    option proto 'dhcp'
    option auto '0'

config interface 'wan6'
    option ifname 'eth1'
    option proto 'dhcpv6'
    option auto '0'
    option reqaddress 'try'
    option reqprefix 'auto'

config route
    option interface 'lan'
    option target '0.0.0.0'
    option netmask '0.0.0.0'
    option gateway '192.0.2.1'

config route6
    option interface 'lan'
    option target '::/0'
    option gateway 'fe80::4e5e:cff:fe40:11aa'
    option metric '1024'

/etc/config/dhcp:

config dhcp 'lan'
    option interface 'lan'
    option ignore '1'

Wireless Network

Setup Wireless as usual.

If you have multiple access points …

  1. Use the same SSID (wireless network name) and PSK (Wi-Fi password) on all access points and the router in your network. Clients will automatically select the nearby station with the best connection quality.

  2. Use different radio channels or set them up to auto-select channels, to minimize radio interference between the stations.

Disable unused Services

Many services are not needed on device used only as access point.

Disable at least the following services, as they might interfere with your router and network:

  • Firewall

  • Dnsmasq, DHCP and DNS service

  • odhcp, IPv6 DHCP server

router$ /etc/init.d/firewall disable
router$ /etc/init.d/firewall stop

router$ /etc/init.d/dnsmasq disable
router$ /etc/init.d/dnsmasq stop

router$ /etc/init.d/odhcp disable
router$ /etc/init.d/odhcp stop

Depending on the desired setup, the OpenWRT device can still be of use for other services as fail-over or load-balancing. For exampleits common to have multiple DNS resolvers in a network.

References