Question Wifi IP error when daisy chain

Oct 4, 2022
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Hello everyone

I wonder if you can explain why I am having this issue.

Firstly I'm in South Africa, so we have load shedding (rolling blackouts) due to the incompetent ANC.
This means I need battery backup for wifi / fibre internet which I have and which works.
But it needs to be energy efficient so I only use 12 volt routers.
All of mine are routers either WAN or WAN DSL 4G types from different manufacturers.

The LAN layout I have is all connected via LAN:
Router 1 attaches to fibre and only this one offers DHCP.
Router 2 connects to router 1
CCTV DVR connects to Router 2
Router 3 connects to router 2
Switch connects to Router 2
VoIP and Router 4 connect to Router 2

Router 2 could have a switch in there which solves the problem, but then it means finding a 12v one and it will use more power.

Fibre plus Router 1 2 3 all run on battery backup. The rest doesn't


Now the problem I'm having is with Router 2 as a daisy chain.
Everything on LAN works and everything on wifi works on other routers except if you move into range of Router 2 it will say "Failed to obtain IP address" often. Not always.

I can use a TPLink VR400 or a DLink DSL-G2562DG and both give the error.
BUT NOT IF THEY ARE USED WITH A SWITCH AND ONLY ONE LAN CABLE TO THEM. Then it never has the error.
Now if I use my old TPLINK 3420 V1 as Router 2 it also has no issues being in a daisy chain.

So why do I have this "failed to obtain IP" error on wifi with this setup? It's not at DHCP negotiation time either - it's each time.
Static IP doesn't seem to help either strangely enough.
I've tried switching off certain settings including firewall but no change.

I'd like to keep the daisy chain without having to get another switch involved if possible.
 
When I was doing something similar with some low power device I used dc-dc converters to get the voltage correct. They make them in any size but for stuff that is low power you can use stuff like this. I did not use these exact ones but they were similar, they are pretty cheap
https://www.amazon.com/Valefod-Efficiency-Voltage-Regulator-Converter/dp/B076H3XHXP

It is somewhat confusing how you have things hooked up. Do you use the wan or the lan ports on the other routers. You need to use the LAN ports if they devices do not have AP mode.

Not sure if it is your problem but when you have multiple routers you must
  1. disable the DHCP in all but the main router.
  2. Change the IP address of the other devices so it does not conflict with the main router and it outside the DHCP range used by the main router. So if they main router uses 192.168.1.1 you would change the other devices to say 192.168.1.250
 

Ralston18

Titan
Moderator
This:

"except if you move into range of Router 2 it will say "Failed to obtain IP address" often. Not always. "

What range of DHCP IP addresses is being allowed to Router 1? Or is there some limit on the number of allowed DHCP nework devices on Router 1?

Or (after re-reading) do you mean "move" within wireless range of Router 2?

= = = =

Are you able to provide a simple sketch of the daisy chained network and post the sketch via imgur (www.imgur.com)?

Show each router, switch, and device including WAN and LAN port connections.

If not then, as I understand the daisy chain (free free to edit and correct the following line diagram):


Router 1, DHCP [ LAN1] ----> [LAN 1] Router 2----> [LAN 2] ---> CCTV DVR
[LAN 3]---->[LAN1]Router 3
[LAN 4] ---->[LAN1] Router 4
[LAN 5] --->[LAN1] Switch 1
[LAN 6] ---> VOIP


There should be no loops.

FYI:

https://kb.netgear.com/000060475/What-is-a-network-loop
 
Oct 4, 2022
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Thank you for the reply
Sorry yes I mean move into coverage range of Router 2.
The DHCP is only covered by Router 1 with a WAN connection to the fibre.
Every other router is connected via LAN ports to the network. No DHCP offered on any of those.

I forgot to mention the Wifi SSID is identical on all routers with same password and WPA2 security. Channels are 1 6 11 as needed with Router 1 and 4 on same channel. All 20MHz. No wifi speed issues anywhere, so it's not a congestion problem.


Topology

FIBRE [LAN 1} ==> Router 1 [WAN]
Router 1 [LAN 1] == Router 2 [LAN 1]

Router 2 [LAN 2] ==> Router 3 [LAN1]
Router 2 [LAN 3] ==> 5 port switch
Router 2 [LAN 4} == Hikvision CCTV DVR

5 port switch ==> Router 4
5 port switch ==> Gradstream 802 VoIP ATA
5 port switch has two additional cables currently not in use and one spare port.

Router 3 and 4 are end of line.

Here is the layout on the house:

 
Although a rather complex setup it should all work fine. Router 2 basically should be running as a switch that has wifi ports.

Since it also fails when you use static IP that means it is unlikely a DHCP issue. Maybe check the LAN ip on router 2 and make sure it is not the same as the main router.
 
Oct 4, 2022
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IP addresses are fine.
Using 10.0.0.1 10.0.0.2 10.0.0.3 10.0.0.4 for the respective routers mentioned (all 255.255.255.0).

Everything works fine except when going into the coverage range of Router 2.
Then it may work or it may drop. A phone will display the wifi with ! or it hops to 4G.

But again as soon as I put a switch at Router 2 and Router 2 is fed off the switch, it NEVER shows this problem. What makes this difference?
 

Ralston18

Titan
Moderator
Regarding:

"But again as soon as I put a switch at Router 2 and Router 2 is fed off the switch, it NEVER shows this problem. What makes this difference?

Does Router 2 come before the switch or after the switch? In my mind the phrasing suggests the latter: Switch ===> Router 2

The photo diagram gives me the impression Router 2 ===> Switch.

Or has it been tried both ways?

= = = =

With or without the switch is there anything plugged into [WAN]Router 2?

Please list each Router (by number) and the Switch: what make and model? Number of ports? Any configurable ports (WAN/LAN)?

For example the TP-Link VR400:

https://www.tp-link.com/eg/home-networking/dsl-modem-router/archer-vr400/

Rightmost Port = LAN4/WAN

Is Router 2 the TP-Link VR400?

What might be making the difference is the specific ports being being used between routers and devices.

Some difference between the various ports with the switch and then without the switch.

Works if the switch in plugged into Router 2 LAN4/WAN but does not consistently work if Router3 or Router 4 is plugged into Router 2 LAN4/WAN.

Or something similar involving the other routers and/or a mis-configured LAN/WAN port.

Interesting.....
 
Oct 4, 2022
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The diagram is correct for how I want it to work.

But I'm talking about adding a switch in place of Router 2 and then Router 2 can plug into that switch.
No other changes made at all and suddenly it works perfectly for wifi on Router 2.
Why does this make a difference is what I don't understand.

Router 1 and Router 3 are Totolink N302R Plus
https://www.totolink.net/home/menu/newstpl/menu_newstpl/products/id/156.html

Router 2 is TPLink
VR400 https://www.tp-link.com/eg/home-networking/dsl-modem-router/archer-vr400/

Router 4 is DLink DG2562

Even if I put Router 4 in place of Router 2 it has exactly the same problem with the Wifi.


Router 3 can go where Router 2 is but then the VoIP doesn't work!
How is that for ridiculous.
 
You have some really strange problem with router 2.

These devices should not have any impact on the ip address when you run them as AP. Putting a extra switch in between should not really have any effect. Even if you wanted to you can not detect these small unmanged switches.

Unfortunately to do more you would have to be able to see the traffic between router 1 and router 2. Consumer equipment does not give this option and even if you inserted a switch that could monitor that might fix/hide the problem since a consumer switch makes it work.

Maybe check the firmware on the router and after that consider finding another older router to do this. These are the type of devices you can find for $5 at garage sales they sell for less than $50 new.
 

Ralston18

Titan
Moderator
Router 1 ------> Router 2 (etc.) = No Wifi.

Router 1 ------> Switch ----> Router 2 (etc.) = perfect Wifi.

Correct?

I do not understand why there is a difference either and agree that it is all very strange. The switch should be transparent.

What is not transparent are the actually physical connections between the routers and switch ports.

And adding in the switch does change ports.

Routers 1, 3, and 4 have a "dedicated" WAN port. Router 2 does not.

Router 2

TP-Link VR400 Router 2 has quite a number of configuration options.

LAN4/WAN port - how configured?

https://static.tp-link.com/res/down/doc/Archer_VR400(EU)_V1_UG.pdf

For example, reference Section 12.5 on physically numbered Page 76. (I have no way to explore or test those admin screens.)

If Router 2 is misconfigured in some manner with respect to LAN4/WAN then that misconfiguration could be involved. And likely so no matter where Router 2 may be physically placed in the network.

Look at the Router 2's LEDs (Page 4) with and without the switch. Likewise look at the switch and other Router's LEDs when the switch is installed.

What about auto-sensing or auto-negotiation? Not due to the switch per se but simply the end physical connections that result.

Take away being the need for a closer look at the port configurations. Especially Router 2 as I understand it all.
 

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