Long Range LAN - WIFI - LAN link problems

Hi, i have an AIS receiver that has been plugged into LAN port of my ISP internet router for some time and it is working fine. The device itself just received VHF broadcasts and sent it online for processing in a group effort to extend marine traffic coverage.
As VHF is a line of site kind of thing i got the idea of getting the said device and antenna as high as possible.
Basically i have built a redundant battery power supply (both solar and wind) and a pair of Tplink CPE 220 V3 wifi AP for the communication both with OpenWRT 19.07.7. One CPE, said AIS device and VHF antenna together with the power supply is already 750m up the mountain.
I tried and tried but cant get the AIS device sending data online again and problem is my very low configuration skills.

ISP router for internet is at and Has DHCP

CPE A has a static mask and gateway
CPE A can go to internet and ping and another LAN computer connected to ISP LAN port
<CPE A connects as client to WIFI AP of CPE B with good signal 3of4 bars (54mbits/updown>
CPE B has static mask gateway
CPE B has bridged (same interface for LAN and WIFI AP)
CPE B can only ping CPE A and cant go online

AIS RECEIVER (showing offline even tho lan is flashing together with CPE B lan indicator.

I tried almost all combinations. even with relayd on one or on other CPE but no success. really frustrating.
Anyone willing to tackle this problem will be mentioned on the plaque that goes up the mountain as soon as config is ready.

WDS would work best here. Configure the AP on A as AP(WDS). Put the B STA(WDS) into its lan bridge. Then when you connect an Ethernet device to CPE B, it should get a DHCP IP all the way back from the main router and have a link to the Internet.

Make sure the DHCP server in both CPEs is disabled. They will be dumb bridges that only transfer packets at layer 2 all the way back to the main router, which does the DHCP and routing.

An alternative way is to make B a routed client. For that B's LAN is different from and it contiunes to run its local DHCP server, serving IPs like onto Ethernet devices like your receiver. CPE A remains a dumb AP on the main router's lan. Set up a wan network proto dhcp on B with its only physical device the client (non WDS) of A. The B wan should get an IP address in A's lan. This will also set up routing from lan devices of B masqueraded into the lan of A and then on to the Internet. An IoT type device will work fine with this configuration.

Note that to administer B from its wan side (which you'll certainly want to do when it's on a mountain), you need to open TCP ports 22 (ssh) and / or 80 (http) from wan in the firewall. Also if you want to log into the AIS receiver as a LAN user you'd need to forward ports to it through CPE B. Because of this additional complexity I'd favor the WDS approach.

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The factory firmware on these has a non-wifi time division multiplexing mode that acts like a "virtual wire" doesn't it? That might be a preferable mode for a point to point link like this.

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What is distance between Node A and B?


:bulb: Did you set Distance Optimization to this on both sides?


(Where's the plaque? :smiley: jk, just make sure this is not causing an intermittent issue.)

Took the #1 suggested approach. IT IS WORKING FINE. Tested on two different devices.
Config is as follows:
CPE A Interface static / GW ISP ROUTER (CPE A pingable / has internet)
CPE A has AP(WDS) and its LAN on same interface
CPE B has Client (WDS) and its LAN on same interface
CPE B Interface static / GW (CPE B pingable/has internet)
AIS device plugged in to one of CPE B LAN ports, has (internet/pingable)

all is as it should be!!

many thanks. for your suggestion. please state how would you like to be refered to on the plaque? your line will go "Special thanks to and OpenWRT community without whom proper operation of this station would not be possible"

Your suggestion is noted and inputted in configuration, OpenWRT sets it to auto, dont know will that work?
Distance Node A to node B is 1470m. calculated as a hypotenuse of 750m vertical and 1265m GPS retrieved horizontal distance.

small note, the plaque will be in Croatian / English

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It does, but i prefer OpenWRT as in the future i plan to put weather station / webcam up there so liberty of configuration and up to date security is essential. with another CPE i could share some internet to clients that are behind the mountain in both mobile/internet blind spot.

I've run WDS mode in my home. The problem with it was that it'd work fine for days and days and then just stop passing packets so that I had to go over and turn the power off and on again to get it to work again.... Having to helicopter up to a mountain peak and switch the power a couple times a month is probably sub optimal :wink:

It might be good to schedule a watchdog that pings something every 10 mins and reboots if it can't ping. Be careful about boot loops.there is an article in the wiki about scheduled reboots that shows how to avoid them

I have also had that problem with WDS on ath9k devices though I would hope that it has been sorted by now.

The watchcat package does exactly what you would want by rebooting on a failure to ping. I suggest setting it up to ping the other CPE rather than some place on the Internet, to avoid nuisance reboots if the ISP link is down. Also don't have the timing so tight that it doesn't have time to establish the link after booting before it decides to reboot again.

I'm running two Atheros CPEs with a BATMAN / 802.11s mesh link. This has been very stable and it can run VLANs on the link. The downside is that it isn't simple to remotely update the remote end since the link itself requires extra packages.

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