Trouble configuring OpenWRT as a "dumb" AP

Installing and Using OpenWrt
1

I'm new to OpenWRT and have been trying to follow along with the wiki article "Wi-Fi Extender/Repeater with Bridged AP over Ethernet", but I'm not able to get this to work correctly.

I'm running OpenWrt 24.10.1 and I've had to reset my TP-Link Archer C7 v5 about a dozen times already trying to get this working. I have searched around the web and around this forum to try to find other posts that would be helpful, but have not found what I am seeking yet.

I want to configure this OpenWRT device to replace my deprecated other "dumb" AP where the upstream router handles DHCP leases for WiFi clients connecting on the specified subnet that the AP is on.

Here is my network config file I have seen others share in other topics here. The OpenWRT device is getting a DHCP lease from the upstream router, which is why WAN is set to dhcp.

config interface 'loopback'
	option device 'lo'
	option proto 'static'
	option ipaddr '127.0.0.1'
	option netmask '255.0.0.0'

config globals 'globals'
	option ula_prefix 'fdee:5858:ba2a::/48'

config device
	option name 'br-lan'
	option type 'bridge'
	list ports 'eth0.1'

config interface 'lan'
	option device 'br-lan'
	option proto 'static'
	option ipaddr '192.168.1.1'
	option netmask '255.255.255.0'
	option ip6assign '60'

config device
	option name 'eth0.2'
	option macaddr '54:af:97:4c:8b:f6'

config interface 'wan'
	option device 'eth0.2'
	option proto 'dhcp'

config interface 'wan6'
	option device 'eth0.2'
	option proto 'dhcpv6'

config switch
	option name 'switch0'
	option reset '1'
	option enable_vlan '1'

config switch_vlan
	option device 'switch0'
	option vlan '1'
	option ports '2 3 4 5 0t'

config switch_vlan
	option device 'switch0'
	option vlan '2'
	option ports '1 0t'

I have the OpenWRT firewall disabled as the upstream firewall will be used.

Before I reset this another dozen times, I'm hoping someone here can help me out. What should I try next?

2

firewall file would be relevant too.

config interface 'lan'
	option device 'br-lan'
	option proto 'dhcp'

change lan interface config as above, move uplink cable to LAN port and stop plus disable dnsmasq.

if it still isn't working, reset, and redo the change above.

1 Like
3

As frollic says. The best way to think about it is that it's already a dumb AP, with extras you don't need.

Ignore the WAN port, plug the LAN bridge into your network, set it to get a DHCP address and you're done with the wired network part. Disabling dnsmasq is essential because it provides a DHCP server and you definitely don't want two of those on your network.

(Later if you feel like messing with it, you can turn off other stuff you don't need and maybe even add the physical WAN port to the LAN bridge, if you need it to also be a switch lots of ports. But doing the above is enough to get you going.)

Edit: you might prefer a static address, so that it's accessible when not connected to your router, for maintenance purposes or whatever. In this case, just make sure to give it an address that's on the same network as your router, but not in the range of DHCP addresses that it gives out.

4

I got some great tips here

Note I'm using a DSA capable unit , so your vlan config might be different

5

Some of the advice here is not necessary if you follow the guide carefully. You don't have to disable dnsmasq, the guide covers how to turn off the DHCP server instance for the LAN bridge interface.

It sounds like the key issue so far is that you've been trying to do this from the WAN port. As mentioned, you can eventually bridge that to the LAN so it can be used as the backhaul or a generic switch port, but to start with, stick with the guide's recommendation of using a LAN port.

It's really easy to block yourself out (or at least make it seem like you have) with small mistakes in this process, so on your first attempt, really try to take the guide word for word.

(I just went through a couple rounds of this myself because I was trying to get a little fancy, i.e. making it a dumb AP for a guest wifi and also a managed switch for several VLANs, and it was so easy to not quite think changes through and then lose access.)

Also remember failsafe mode for easily fixing most access problems. I had forgotten about that and spent way too much time re-flashing when I screwed up.

6

indeed, but it's easier to do it for a newcomer, than disabling the DHCP, and it'll free up additional RAM (not that you really need it on an AP).

7

Actually, I would argue that disabling DHCP explicitly in the config is more important for newcomers. The reason is that the disabled services (dnsmasq in particular) are often re-enabled after a sysupgrade. A new user may not realize that has happened and it can (and will) cause major problems on the network that are difficult to debug for those not already aware of the issue and symptoms.

4 Likes
8

Thank you everyone for your help. I was able to get it all working following the wiki page carefully.