Question Weird LAN/Wifi issue - must read

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
 
Last edited by a moderator:

kanewolf

Titan
Moderator
Do "WIFI A" and "WIFI B" have unique SSID?
Does internet access drop or only local device access?
What happens if you turn off WIFI after connecting to "B" but before connecting to "A" ?
If you had an app to ping from the phone, can you ping the NAS ?

There is probably an ARP cache on the switch that is causing the problems, but with unmanaged devices you don't have any insight.
 

LWFG001

Commendable
Apr 12, 2017
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Since you are using the TP-Link TL-WR0146ND (WiFi B) as a wireless access point, check to see if you've configured that router as a wireless access point correctly by reading this:

https://www.tp-link.com/ae/support/faq/417/

^ Carefully follow all of the directions in each of the seven steps. In my experience, setting up the non-primary router as a dedicated wireless access point correctly, solves the problem you're sharing.
 
Nov 2, 2019
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Since you are using the TP-Link TL-WR0146ND (WiFi B) as a wireless access point, check to see if you've configured that router as a wireless access point correctly by reading this:

https://www.tp-link.com/ae/support/faq/417/

^ Carefully follow all of the directions in each of the seven steps. In my experience, setting up the non-primary router as a dedicated wireless access point correctly, solves the problem you're sharing.
Hi,
everything is set correctly (according to the linked manual), but the issue persists
Marcel
 

LWFG001

Commendable
Apr 12, 2017
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SSID doesn't matter if the non-primary router is configured as a wireless access point for the main router. The non-primary wireless access point router can use the same SSID as the main router.

The ProSafe 24 Port Gigabit Switch switch is unmanaged and doesn't store routing protocol information. It only stores MAC addresses and port info. Unplugging it and plugging it back in should refresh the MAC address table in the switch's RAM buffer. https://www.downloads.netgear.com/files/JGS524F_IGprt_9Jan12.pdf


Do "WIFI A" and "WIFI B" have unique SSID?
Does internet access drop or only local device access?
What happens if you turn off WIFI after connecting to "B" but before connecting to "A" ?
If you had an app to ping from the phone, can you ping the NAS ?

There is probably an ARP cache on the switch that is causing the problems, but with unmanaged devices you don't have any insight.
 
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Nov 2, 2019
37
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Do "WIFI A" and "WIFI B" have unique SSID?
Does internet access drop or only local device access?
What happens if you turn off WIFI after connecting to "B" but before connecting to "A" ?
If you had an app to ping from the phone, can you ping the NAS ?

There is probably an ARP cache on the switch that is causing the problems, but with unmanaged devices you don't have any insight.
To answer your questions:
Yes, wifi A and B have unique SSIDs.

Only access to local devices drops - only those that are connected using wired
connection - my SAT receiver goes to the Switch first then to the Router and my NAS goes directly to the Router - neither is accessible within the said 8 minute window.

If I turn off wifi in between, nothing happens - result is the same - no access.

I had apps to ping from my phone and my tablet - ping does not work either - not before the 8 minutes elapse.

Is there something I can do to clear the ARP cache? Not sure what that is :)
Marcel.
 

LWFG001

Commendable
Apr 12, 2017
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He's saying the routing ARP table stored in flash memory on your unmanaged switch should be flushed and allowed to rebuild but an unmanaged switch doesn't process or store that kind of layer 3 router protocol information. It only works with layer 2 device MAC addresses.

So just unplug and replug in your switch to rebuild the MAC address table. It doesn't hurt to do that and it's easy so unplug it and replug it back in. Then move on to the below.

OK, to me it looks like your devices might be losing their IP addresses when you switch from WiFi B to WiFi A and have to wait for DHCP to issue them new ones. Try this:

1. Connect your wireless device to the WIFI A router. Now Log into the WIFI A router from a computer and look at "connected devices" screen in that router to verify the wireless device is connected to the WIFI A router. Write down the IP address the WIFI A router assigned to the wireless device.

2. Now, connect the same wireless device to the WiFi B router. Look on the computer and see if the device disappears from "connected devices" on the WiFi A router. Did it disappear?

Whether or not it disappeared as a connected device on the WIFI A router, check the IP address on the wireless device and see if is present and the same IP address the WIFI A router originally assigned to the wireless device before you connected it to the WIFI B router. Is the IP address present and the same?
 
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Nov 2, 2019
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He's saying the routing ARP table stored in flash memory on your unmanaged switch should be flushed and allowed to rebuild. Just unplug and replug in your switch. I don't believe that's the problem though. But doesn't hurt to do it and it's easy so unplug it and replug it back in. Then move on to the below.

OK, to me it looks like your devices are losing their IP addresses when you switch from WiFi B to WiFi A and have to wait for DHCP to issue them new ones. Try this:

1. Connect your wireless device to the WIFI A router. Now Log into the WIFI A router from a computer and look at "connected devices" screen in that router to verify the wireless device is connected to the WIFI A router. Write down the IP address the WIFI A router assigned to the wireless device.

2. Now, connect the same wireless device to the WiFi B router. Look on the computer and see if the device disappears from "connected devices" on the WiFi A router. Did it disappear?

Whether or not it disappeared as a connected device on the WIFI A router, check the IP address on the wireless device and see if is present and the same IP address the WIFI A router originally assigned to the wireless device before you connected it to the WIFI B router. Is the IP address present and the same?
Well, I did a quick test:
Connected to WIFI A - TV works
Then connect to WIFI B - TV works
Connect back to WIFI A - TV does not work
Unplug switch for 5 seconds, plug it back in - TV works immediately - no waiting for 8 minutes.
Repeated 3 times to be sure.
Now what?


As for the other procedure you suggested:
When connected to wifi A my tablet was listed with IP 192.168.0.7 among wireless devices.
After connecting to wifi B it was listed with IP 192.168.0.7 among wired devices.
After connecting back to wifi A it moved back to the list of wireless devices with the same IP 192.168.0.7.
Also, when I check on the tablet, the IP remains the same all the time.
 
Nov 2, 2019
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I have noticed the secondary router (TP LINK wifi B) offers several Wireless Mode options - on mine the currently selected option is AP
other available options are:

Client
Client Bridge (Routed)
Ad Hoc
WDS Station
WDS AP

Which option should I use?
Like I said, the TP LINK has a wired connection to the primary router, all I need from the TP LINK is to provide WiFi coverage upstairs.
 

kanewolf

Titan
Moderator
I have noticed the secondary router (TP LINK wifi B) offers several Wireless Mode options - on mine the currently selected option is AP
other available options are:

Client
Client Bridge (Routed)
Ad Hoc
WDS Station
WDS AP

Which option should I use?
Like I said, the TP LINK has a wired connection to the primary router, all I need from the TP LINK is to provide WiFi coverage upstairs.
Access point is the correct mode for a wired link back to your primary router.
 
Nov 2, 2019
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After you reset power to the switch, is the 8.5 minute wait still present with further tests? Or does it eventually come back?
The wait is still present - immediately. I did the tests back to back and the wait was there every time - until I reset the power - then it was gone.
I presume that time limit is the cycle time of the switch doing something to reset routing data or something else.
Is there a way to force it to do that? Or force either router do do something that will cause the reset?
 

LWFG001

Commendable
Apr 12, 2017
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1. If you know how to check each router's firmware to make sure it's up-to-date, and update the firmware correctly if it is not up-to-date, then go ahead. If you do not know how to update your router firmware, then skip it and move to step 2.

2. Check the radio setting on each router. Go into each router's wireless settings and see what channel numbers each router is using. Whether they are set to Auto or a specific number, read this: https://www.lifewire.com/choose-the-best-wifi-channel-for-your-router-2378202 then change the channel number on each router as needed.

Note that the channel number is especially important for 2.4 GHz channels and dual band routers (these use both 2.4Ghz and 5Ghz). Try using a different channel than the default listed for each 2.4Ghz and 5Ghz, per the article. Each channel number on your network should be unique. Do not use the “auto” setting. Channels 1, 6, and 11 are preferred for 2.4Ghz and a higher channel for 5Ghz. It’s very possible that there are enough networks in your immediate area on the same channel that they’re conflicting with each other, thus one of the routers is dropping the connection when you move between them.

If problem persists after getting the channel numbers sorted properly on each router afterwards, try this:

3. Temporarily turn off extra security features, if they are enabled, like MAC address filtering or network isolation or Wi-Fi Protected Setup.

4. Try setting the wireless network mode to Mixed. Sometimes picking a higher mode can cause problems with older devices or even some of the newer android devices.

Did any of these solve the problem?
 
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Nov 2, 2019
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1. If you know how to check each router's firmware to make sure it's up-to-date, and update the firmware correctly if it is not up-to-date, then go ahead. If you do not know how to update your router firmware, then skip it and move to step 2.

2. Check the radio setting on each router while we're at it. Go to each router's wireless settings and see what channel number each router is using. Whether they are set to Auto or a specific number, read this: https://www.lifewire.com/choose-the-best-wifi-channel-for-your-router-2378202 then change the channel number on each router as needed.

This is especially important for 2.4 GHz channels and dual band routers (these use both 2.4Ghz and 5Ghz).

Try using a different channel than the default listed for each 2.4Ghz and 5Ghz, per the article. Each channel number on your network should be unique. Do not use the “auto” setting. Channels 1, 6, and 11 are preferred for 2.4Ghz and a higher channel for 5Ghz. It’s very possible that there are enough networks in your immediate area on the same channel that they’re conflicting with each other, thus one of the routers is dropping the connection when you move between them.

If problem persists after getting the channel numbers sorted properly on each routerwards, try this:

3. Temporarily turn off extra security features, if they are enabled, like MAC address filtering or network isolation or Wi-Fi Protected Setup.

4. Try setting the wireless network mode to Mixed. Sometimes picking a higher mode can cause problems with older devices or even some of the newer android devices.

Did any of these solve the problem?
Hi,
thanks for the suggestions, but those are all fine. We live in a family house and there are no other networks in range.
Did you see my posts regarding the switch? That seems to be the main issue.
Marcel.
 

LWFG001

Commendable
Apr 12, 2017
134
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Did you see my posts regarding the switch? That seems to be the main issue.
Marcel.
Yes but I didn't understand what you were posting. Were you saying that when you powered off the switch and turned it back on the 8.5 minute drop for wireless devices passing from WiFi B to WiFi A was temporarily gone but then resumed when you repeated the process passing back to WiFi B then to WiFi A a second time and every time thereafter?
 

Ketchup79

Notable
Aug 7, 2019
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This is only an "educated" guess, but :
  1. The MAC address tables on that switch don't like looking to another location for the same device, so it takes it a minute to adjust. We you power it off/on, it is ok with wherever it is when the device starts up.
  2. Is there any particular reason your SAT is plugged into your switch but your NAS is plugged into the router?
 

LWFG001

Commendable
Apr 12, 2017
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We're close to isolating the problem if it's related to the switch. I need a correct answer to my post #15.
 
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Nov 2, 2019
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Yes but I didn't understand what you were posting. Were you saying that when you powered off the switch and turned it back on the 8.5 minute drop for wireless devices passing from WiFi B to WiFi A was temporarily gone but then resumed when you repeated the process passing back to WiFi B then to WiFi A a second time and every time thereafter?
Yes, that is correct. Powering the switch off and on fixed the issue temporarily, but it reappears after each switch from wifi B to A.
 
Nov 2, 2019
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This is only an "educated" guess, but :
  1. The MAC address tables on that switch don't like looking to another location for the same device, so it takes it a minute to adjust. We you power it off/on, it is ok with wherever it is when the device starts up.
  2. Is there any particular reason your SAT is plugged into your switch but your NAS is plugged into the router?
I thought that connecting the NAS directly to the router will be better for all wireless devices which need data from it. They don't have to go through the switch. I cannot change the setup now as the cables are in the walls and the devices are in different parts of the house. I think the switch is at fault with my issue, but I have no idea how to resolve it.
 

LWFG001

Commendable
Apr 12, 2017
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Yes, that is correct. Powering the switch off and on fixed the issue temporarily, but it reappears after each switch from wifi B to A.
Acknowledged. Researching.

P.S. I do not see how connecting your network area storage (NAS) device directly to a router port rather than a switch port would be a problem; however, I always plug my NAS devices into the switch. But let's try it. Plug the NAS into the switch then unplug and replug in the switch and retest moving a wireless device from WIFI B to WIFI A twice to see if the problem remains afterwards while we research your switch specs and look for the problem.

P.P.S. Are you using different types of network cabling on your local area network (LAN)? These are the cables which connect wired devices (like your NAS) to the router or the switch. I have seen connectivity and performance problems arise from using different types of network cable on the same LAN many times which cleared up as soon as I standardized cabling to either all CAT 5e or all CAT 6 rather than cabling being mixed.

And I don't care that the router and switch manuals say you can mix cables because time-and-time again I've seen connectivity and performance problems (including affecting wireless connectivity and performance from the router) result as the wired/wireless router and the switch struggled to "thunk" the different traffic speeds over different network cables with different specifications on the same LAN. Those problems cleared up immediately after I put everything on CAT 5e or CAT 6.

I prefer CAT 6 or CAT 6a personally but CAT 5e will do. I've seen problems with CAT 7 and don't recommend it.
 
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Nov 2, 2019
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Acknowledged. Researching.

P.S. I do not see how connecting your network area storage (NAS) device directly to a router port rather than a switch port would be a problem; however, I always plug my NAS devices into the switch. You might want to try plugging it into the switch and retest while we research your switch specs and look for the problem.

P.P.S. Are you using different types of network cabling on your local area network (LAN)? These are the cables which connect wired devices (like your NAS) to the router or the switch. I have seen connectivity and performance problems arise from using different types of network cable on the same LAN many times which cleared up as soon as I standardized cabling to either all CAT 5e or all CAT 6 rather than cabling being mixed.

And I don't care that the router and switch manuals say you can mix cables because time-and-time again I've seen connectivity and performance problems (including affecting wireless connectivity and performance from the router) result as the wired/wireless router and the switch struggled to "thunk" the different traffic speeds over different network cables with different specifications on the same LAN. Those problems cleared up immediately after I put everything on CAT 5e or CAT 6.

I prefer CAT 6 personally but CAT 5e will do. I've seen problems with CAT 7 and don't recommend it.
Regarding the different nas and sat connection - I don't think it is the source of the problem I was just explaining why I did it this way, cause someone asked. I cannot connect the nas to the switch as I'd have to buy a really long patch cord.

As for the cabling - When we rebuilt our house 2 years ago, I wanted to future-proof the LAN, so I used CAT7 everywhere. Right now it's just 1 gigabit, but when 10 gig hardware gets cheaper... The only thing that is not cat7 are the patch cords going from the wall sockets to individual devices. Do you think I should unify those too? Cat7 as well?
 

Ralston18

Titan
Moderator
A little late here but I am curious about the IP addresses.

My understanding is:

- Router A (WIFI A) is the main router at 192.168.0.1 configured as the DHCP with the available IP DHCP IP address range being 192.168.0.2 to 192.168.0.199

- Router B (WIFI B) has been assigned a reserved static IP of 192.168.0.250 outside of Router's A available IP address range. DHCP disabled on Router B. ( Edit note: added underlined words to clarify.)

- SAT (being 192.168.0.200) and the NAS (being 192.168.0.201)

SAT and NAS using Static IP addresses and reserved by MAC on Router A or Router B? "Leftover"?

Where is the iPad's IP address of 192.168.0.205 coming from? Should be Router A (WIFI A) if I followed the preceding posts correctly. However, 192.168.0.205 is outside of the allowed DHCP IP address range.

Phone (Android) ?

May have missed something but I am still compelled to ask.
 
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LWFG001

Commendable
Apr 12, 2017
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If you're using CAT 7 everywhere, from the wall plugs which computer devices plug into through the walls to the switch and from the switch to the router, that part is standardized.

BUT you are using different cable types from the computer devices to the wall plugs. I would replace those cables with the same CAT 7 scheme. Everything on the same cable type.

Be back later with info on the switch.
 

LWFG001

Commendable
Apr 12, 2017
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I need to ask you for the unmanaged Netgear ProSafe 24 port gigabit switch MODEL NUMBER.

What is the MODEL NUMBER of the switch?

It might be JGS524v2 for example.
 

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