Not accessible after disabling DHCP

Hi all,

i've bought a used TP-LINK Archer C5 V1.2
Upgrade to OpenWRT with latest version of LEDE went fine, all options are working.

The router should be used as an access point on 2nd floor connected via LAN cable to my router in basement.
For this i wanted to have the device configured without DHCP, the router below is already one and should deliver the IP-Adresses.

So i changed the setting of the interfaces, but now the configuration page is not accessible any longer.
Once it's connected to the LAN cable via WAN interface, i do not have internet access.

After plugging the cable from the below router to LAN1, i have full internet access via LAN and both WLAN interfaces (2.4G, 5G), but the TP-LINK is still inaccessible.

The device seem to be working in general, but i cannot access the interface. Tried it via Telnet/SSH, no success.
Even going to failsafe brings the device to the mode where i can ping (after manually set my computer to the required network setting)
But Telnet is not working, it always say "Connection refused".
Both (Ping and not working Telnet) are independent from the WAN/LAN switch i am using.

As the device is new, i'm looking for a different option to run a factory reset. The normal procedure provided by TP-LINK does not work any longer (i assume because no TP-LINK firmware is installed any longer).

Any highligting ideas to this issue are much appreciated.

EDIT: I've tried running an Nmap on the IP-Adress of the router.
Result: All 100 scanned ports on are closed (that's the IP of the router getting from the other one).
But it's still pingable.

EDIT2: I have connected a NAS device to one of the LAN ports. Also not reachable. It only works if i switch the connector from WAN to any available LAN port.

So the result is that is's working like a simple switch (including WLAN) but it's not configurable any more.

I have to report a first success.

After trying the failsafe mode two times i found out the problem.
The router is not listening on port 23 for telnet, but 22 for SSH
After a port scan while in failsafe it showed port 22 open

And bam!, i was able to login with root using SSH command.
Firstboot resetted the router and all is working.

I only have one problem:
I can access the web interface only while connected to the router WLAN/LAN. If i am connected to my basement router and try to access the IP-Adress of the TP-Link, it does not work. Both routers are connected via LAN.

Once i connect to the WLAN of the TP-Link, beside full internet access also the web interface works.

Any ideas about that? Would it help to disable the firewall on TP-Link? I do not need it because my basement router has it enabled already.

Thanks in advance

If you are using this as a dumb AP, you don't want to be using the WAN port. Instead, try following this guide.

Alternatively, you can simply change the IP address of your LEDE/OpenWRT router to an available address (i.e. not the same as your main router or any other static IP on your network and outside the DHCP range set by your main router). Then turn off the DHCP server on your LEDE/OpenWRT router, and connect a cable between a LAN port on your main router and a LAN port on your LEDE/OpenWRT router. You should be good to go.

EDIT: revising link

I will give it a try, thanks.

Maybe i found the initial error from my first posting. Potentially i added a static IP adress to the TP-Link which is in the DHCP-Range of my primary DSL router.

Now that failsafe works, i will check these options.


Just to complement the previous advice: remember to also set the gateway and DNS address on the new dumb AP. Otherwise the router itself will be unable to access internet (although clients connected via it will be, as they use DHCP to get address from the main router.)

Old advice written by me:

If you connect the two routers using a fixed connection between LAN ports, the whole thing is ridiculously easy, as you can dumb down the APs. (The key to making things really easy is to NOT use the WAN port in the slave APs at all.)

Basically you need to adjust these in router2:

  • set the hostname to be different than the main router has
  • set router2’s LAN interface to match the subnet of router1, but to have a different fixed IP address. I use
  • set that router’s DNS and gateway info to point into router1 ( in my case)
  • config the DHCP server in router2 to ignore requests from local LAN interface. I do that config to prevent mishaps with the service starting accidentally, although I also disable the service itself (dnsmasq).
  • disable the DHCP/DNS service (dnsmasq) in router2
  • config the Wifi normally. At least change the wifi channel to prevent signal overlap.

i will check this advice also.

That's what i set up earlier, but for whatever reason, something went wrong and the error described in my initial post.

I have another question, not sure if i need to open a new thread or if it's answered already:

I want to have the WiFi Interfaces disabled during night time, while the router should remain online for the LAN attached NAS.
I know about the WLAN switch on it's back, but i want to have it set more comfortable.
Does a cron job helps here?

What about the syntax? Some suggested to add "root" in front of the command, others say it's works straight forward.
And which interfaces do i need to disable to switch it off? wlan(0/1) or radio(0/1)?

crontab would likely be

0 23 * * * wifi down
0 7 * * * wifi up

read also

This will do the job only once a year... Day 0 in week 0 in month 0.

He would mean:

0 23 * * * wifi down 
0 7 * * * wifi up
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yep. my bad.
thanks for correcting

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Many thanks,

Meanwhile i played around with the statistics app available.
Did exactly what you suggested, but a little more comfortable for me as a Windows user :rofl::joy::rofl:

If your problem is solved, please consider marking this topic as [Solved].

The problem itself is not yet fully resolved.

I've followed the suggestion and connected the OpenWRT-Router via LAN cable (on first LAN socket) to the router downstairs. I've iven it a static IP adress ( which matches to the ADSL router downstairs ( This IP is also outside the DHCP-Router of the ADSL device ( and upwards).

For whatever reason i am not able to connect to the OpenWRT router any longer by using his IP-Adress. Any attempt failed.
A port scan to this router shows "all ports closed".

Any idea what i did wrong and how to solve it?


@hnyman, I have got to this exact point. Followed the Dumb AP advice (disabled the 3 services AFAIK) but am not able to access the OpenWrt interface.

Any device connected to the router's Wi-Fi works fine and can access the internet. The allocated static IP shows up on my main router, but it seems all ports are closed.

I'll obviously have to start again, but how to I ensure I can access the Interface?


RTFM - Hard restart solved the problem.

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