[SOLVED] Weird LAN/Wifi issue - must read

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Nov 2, 2019
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Hello,
In my house I am using a LAN as shown on this simplified drawing.
The primary router 192.168.0.1 is a Netgear D7000 VDSL router with the latest original firmware and the secondary 192.168.0.250 is a TP-Link TL-WR0146ND with DD-WRT v24SP2 (DHCP disabled) – connected via cable and used to improve WiFi coverage upstairs in my house. The switch is an unmanaged Netgear ProSafe 24 port gigabit switch.

When connecting using different wireless devices with both iOS and Android I have the following issue:
If the devices connect via WiFi A on my primary router, they can access the SAT receiver and the NAS without any issues.
When I connect them using WiFi B on my secondary router, both devices can access the SAT receiver and the NAS without any issues.

However, when I now switch back to WiFi A, neither device can access the SAT receiver and the NAS.
They don‘t see the devices on the network and cannot even ping them.
This situation lasts for some 8 minutes and 30 seconds after which the SAT and NAS become pingable and visible from my iOS and Android devices (this applies to all wired devices connected to my switch – all become visible after the said 8 minutes 30 seconds).

If I repeat this process – Wifi A – WiFi B – WiFi A the result is always the same and it takes 8.5 minutes till the SAT receiver and the NAS are visible on WiFi A again.

I have absolutely no idea what can be causing this. There are no other issues with the network, all wired and wireless devices are working properly, the speeds are good, the VDSL connection works fine. The issue now exists over 2 years and in that time the Netgear received several firmware updates, but nothing has changed.
Any advice appreciated.
Marcel
 
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Solution
Re-categorized problem to "Roaming wireless delays".

Reason (full disclosure) could not think of anything else.

Some googling along those lines brought up a number of potential causes - Switches being one of them....

I found the following Cisco page:

https://documentation.meraki.com/MR/WiFi_Basics_and_Best_Practices/Roaming_Technologies

And a Deju Va link:

https://community.netgear.com/t5/Orbi/Random-ARP-Problems-w-WiFi-nodes/td-p/1799406


Then I came across Roaming aggressiveness:

https://www.versatek.com/blog/how-t...reception-by-boosting-roaming-aggressiveness/

A wireless device being at some threshold location and bouncing back and forth with every other device trying to keep up - what...

LWFG001

Commendable
Apr 12, 2017
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On the new network diagram the Chromecast and Router B have the same IP (192.168.0.202).

Chromecast as "MAC Reserved" and Router B as "Static.

Router B not appearing as a wired device.

I see that too but the way Chromecast setup works is that it connects to the network via DHCP over wireless on Router B and so Chromecast is not actually using the same IP address as Router B but rather pulling a DHCP IP address over Router B's WiFi.

Furthermore, when two computers or devices use the same IP address on the same local area network it renders either one or both of them unusable on the network. Meaning that if Router B is working and Chromecast is also working, then they are not actually both using the same IP address.

Plus, the Chromecast would issue an error message.

Bottom line: The Chromecast is getting it's IP address from Router B but they are not actually using the same IP address even though the network diagram he posted shows it as such.
 
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Nov 2, 2019
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They don't. The operating systems in computers and other networkable devices are designed to prevent that from happening in the way I previously explained in post #42.
They don't. The operating systems in computers and other networkable devices are designed to prevent that from happening in the way I previously explained in post #42.
Well, I was asking because on the linked website Netgear lists this as one of the possible causes of network loops.
One more question: how much more insight into the network issues would a managed switch give us, say this one: NETGEAR ProSAFE 16-Port Gigabit Smart Switch, GS716Tv3?
Or, please recommend a good 16-port gigabit smart switch that costs around 100 dollars/euros.
 

LWFG001

Commendable
Apr 12, 2017
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I think you should obtain an inexpensive unmanaged 10/100/1000 switch from a local store with a no questions asked refund policy and swap out your existing switch. If it resolves the problem, that was the problem. If it does not, take the switch back for a full refund and keep using your existing switch because the switch will NOT be the problem.
 
Nov 2, 2019
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On the new network diagram the Chromecast and Router B have the same IP (192.168.0.202).

Chromecast as "MAC Reserved" and Router B as "Static.

Router B not appearing as a wired device.

Sorry about that - that is a copy/paste mistake - Router B should be 192.168.0.250.
I modified the diagram accordingly.
 

LWFG001

Commendable
Apr 12, 2017
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Network diagram updated, got it.

And I messaged you back with the right switch to buy. For the price, it's the best one out there.

Are you getting everything on the same cable type?
 

LWFG001

Commendable
Apr 12, 2017
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Don't forget to replace that old CAT 5e cable on Router B with a nice new CAT 6a cable when you replace ALL non-CAT 6a cables on your network.

Also carefully check the cables connecting Router A to the switch and the NAS to Router A. Those are most important. If they are CAT 6 or some other cable type which is not CAT 6a, or they are old, then you should replace them.

I honestly don't care what others say about different cables being all supposed to work together because I've seen the problem too many times in networks with mixed CAT types of cabling. I hope you ordered enough CAT 6a cables. CAT 6a on everything.
 
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Nov 2, 2019
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Don't forget to replace that old CAT 5e cable on Router B with a nice new CAT 6a cable when you replace ALL non-CAT 6a cables on your network.

Also carefully check the cables connecting Router A to the switch and the NAS to Router A. Those are most important. If they are CAT 6 or some other cable type which is not CAT 6a, or they are old, then you should replace them.

I honestly don't care what other say about them all supposed to work together because I've seen the problem too many times in networks with mixed cabling. I hope you ordered enough CAT 6a cables. CAT 6a on everything.

I counted all my devices and ordered enough plus two spare ones. As for the other cables, those are all in the walls, but I'm positive those are all cat6a (I personally bought a 300 meter roll and supervised the routing). Also, all the connectors and wall sockets are all cat6a.
 

LWFG001

Commendable
Apr 12, 2017
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Hoping that the switch arrives soon...

He ordered a good one that's easy to setup and use. It's the TP-Link 16-port smart Gigabit Easy Smart Switch (TL-SG1016DE).

If I remember correctly, the switch can be easily put in an unmanaged switch state and simply used as an unmanaged switch until the owner is ready to make configuration changes; however, TP-Link technical support can provide further information on switch setup and use:

Toll Free: 1-866-225-8139
Service Time: 24 hours a day, 7 days a week
 
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Nov 2, 2019
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He ordered a good one that's easy to setup and use. It's the TP-Link 16-port smart Gigabit Easy Smart Switch (TL-SG1016DE).

If I remember correctly, the switch can be easily put in an unmanaged switch state and simply used as an unmanaged switch until the owner is ready to make configuration changes; however, TP-Link technical support can provide further information on switch setup and use:

Toll Free: 1-866-225-8139
Service Time: 24 hours a day, 7 days a week

Just a quick update - I have modified my order to also include a cable tester, unfortunately everything will not be delivered before Monday next week. I will update then.
At least I will have time to study how to configure a managed switch :)
 

LWFG001

Commendable
Apr 12, 2017
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Just a quick update - I have modified my order to also include a cable tester, unfortunately everything will not be delivered before Monday next week. I will update then.
At least I will have time to study how to configure a managed switch :)

No problem. And TP-Link tech support is great at setup and configuration of these easy to use switches.
 
Nov 2, 2019
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Ok, here is the current situation:
Today I have received all the new equipment.
As a first step, I have used a tester to check all the cables in my house and I have discovered there are NO FAULTY WIRES, however, there are two different types of wiring (no idea why, as it was done by the same person):
All my wall sockets on the ground floor test as follows:
1 2 3 4 5 6 7 8 G
3 6 1 4 5 2 7 8 G
All my wall sockets on the first floor test as follows:
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
There is NO SIGNAL for GROUND on the first floor in any of the sockets.

Do you think this can be causing some issues?

I tried to connect Router B downstairs to see if anything changes when I do the WiFi A-B-A switch- the issue is still there - my iPad doesn't see any wired devices - not before the 8 minutes elapse.

Step two will be replacing all non CAT6a patch cords with new CAT6a patch cords. Update soon.
 

Ralston18

Titan
Moderator
Nov 2, 2019
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What tester did you use?

On ground floor are any wall sockets or their respective cables labeled "crossover"?

What labeling is on the cables: e.g., 568A or 568B?

For more information:

https://www.comparitech.com/net-admin/difference-between-straight-through-crossover-rollover-cables/

https://www.lifewire.com/crossover-cable-ethernet-817870

Are you able to determine if the color coded wires match the standards?
When we rebuilt our house I bought all the network components - they were all the same for all of the house. There was a single 300 meter roll of cable which is installed everywhere and there are the same CAT6a wall sockets everywhere. So the guy who was crimping the RJ45 connectors on one end and connecting the sockets on the other end must have done it differently on the ground floor and the first floor (due to building work, there was a time gap of about 1 month between installing the sockets on the ground floor and the first floor). So I basically know, why the connections are different. The question is whether it can negatively impact my network.
 

Ralston18

Titan
Moderator
Newer switches may detect the type of cable/connection and adjust between straight and crossover.

However, just the difference between the ground floor and first floor is problematic.

Is there a patch panel somewhere?

My view is that all of the wall outlets (ground floor and first floor) should be consistently wired.

Also, going back a bit, regarding No Signal for Ground: UTP does not require grounding and doing so may cause problems.

I believe that you may need a "do-over" with respect to the ground floor outlets.

There may be other thoughts and ideas.
 
Nov 2, 2019
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After step three - replacing the switch - still no change. After going from Wifi A to B and back to A my wireless devices don't see the wired ones for about 8 minutes and 30 seconds. Disconnecting the power on the new switch and connecting it back produces the same result as with the old switch - the problem disappears and I see all devices.
I will presumably keep the managed switch and sell the old one, as it's fine and I have a 2 year warranty on the new one.
Unfortunately this means we still don't have a solution. What now?
 
Nov 2, 2019
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Newer switches may detect the type of cable/connection and adjust between straight and crossover.

However, just the difference between the ground floor and first floor is problematic.

Is there a patch panel somewhere?

My view is that all of the wall outlets (ground floor and first floor) should be consistently wired.

Also, going back a bit, regarding No Signal for Ground: UTP does not require grounding and doing so may cause problems.

I believe that you may need a "do-over" with respect to the ground floor outlets.

There may be other thoughts and ideas.

No, there is no patch panel, the cables run straight to the wall sockets on one end and on the other end straight to the switch (RJ45 only).
Since the CAT6a cables have a ground wire, should not everything have ground rather than not have it? Even the CAT6a patch cords I bought test 1 2 3 4 5 6 7 8 G.
 

LWFG001

Commendable
Apr 12, 2017
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Unfortunately this means we still don't have a solution. What now?

Are all old cables replaced with new cables including those connected to both routers and the NAS?

^ I'll assume so unless told differently. So all cables and the switch were replaced. That's good, now you have a proper physical level infrastructure which a LAN should have.

Next, we look at the IP scheme. The diagram leaves many questions. Let's dig in. The following devices are outside of Router A's DHCP range but not marked as static on the diagram. So I'm going to ask:
  1. Is Router A on a static IP address?
  2. Is the NAS on a static IP address?
  3. Is PC1 on a static IP address?
  4. Is PC 2 on a static IP address
  5. Is Chromecast on a static IP address?
  6. Is the Printer on a static IP address?
Next, the only DHCP range (192.168.0.2 to 192.168.0.30) you have on your network diagram comes from Router A. You said Router B has DHCP disabled but would you recheck that? We must know for sure:

  1. Is Router B setup to issue IP addresses via DHCP?
  2. See HERE. Which version is Router B (TL-WR0146ND); is it V1, V2, or V3?
We are looking for possible IP address conflicts, whether or not a wireless device is being issued an IP address by router B which it has to drop and pick up a new IP address when it moves within range of Router A, etc..

Now watch the following video and then ensure Router B (TP-Link TL-WR0146ND) is correctly configured as a wireless access point (WAP) to Router A on a wired (not wireless) connection either in access point mode or manually configured.

You can reach out to the TL-Link community https://community.tp-link.com/us or contact TL-Link directly https://www.tp-link.com/us/support/contact-technical-support/ for further help configuring Router B (the TP-Link TL-WR0146ND) as a network access point.

View: https://youtu.be/Cg_gGECGLiY
 
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Nov 2, 2019
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What is the labeling on those CAT6a cables?

Ground floor and First floor?

Are they CAT6A U/UTP or CAT6A F/UTP or something else?

What connectors were used on the cable ends going into the Switch?

PS: What Tester did you use?
On all of the cables it says F/FTP CAT 6A EXTRAPOLATED TO 625MHZ,
As for the connectors, they are RJ45 CAT6A STP 8p8c shielded
The tester is this: DATACOM Cable Tester LED (RJ45,12,11) 4581
The patch cords I just purchased are S/FTP CAT 6A.