help with Wifi Roaming bug in archer c6

[abhijithas]

My current setup is as follows: I have a bsnl(my ISP) broadband over DSL connecting to an Iball ibaton 150M wireless-n adsl2+modem router (@192.168.1.1) in bridge mode, and an archer c6(@192.168.0.1) in router mode setup in PPPoE. the archer c6 covers the first floor of my home. I have run a cat 6 cable from the archer c6 to another Iball modem/router(@192.168.0.2) (same model as the main modem in bridge mode) on the ground floor which is in AP mode (DHCP disabled).
I have configured both the archer c6 and the iball in AP mode with the same SSID, password, and security protocols(WPA2-PSK, AES) to have a seamless handoff when I move around while using my phone. I'm using a Oneplus 7 pro.

Wifi hand off works perfectly. when I'm connected to the archer c6 when I'm in the same room as the router, it connects to the 5 GHz band. when I leave the room, it will switch to 2.4 GHz. and when I go downstairs, the phone switches to the AP downstairs seamlessly. Now, if I come back upstairs, the phone switches to the 2.4 GHz and then to the 5 GHz as I enter the room without any hurdles too. The problem is that after the phone switches to archer c6, i lose proper connectivity. I have some connectivity as in I can send/receive texts or browse the web, but it's like something is messing up the bandwidth. youtube doesn't load, cannot make video calls and a speed test at this point gives me 0.07-0.1 Mbps in place of 8.2 - 8.3 Mbps download speed I should get. I have to wait around a couple of minutes before I get proper connectivity. I don't know exactly how much time i have to wait before the connection is okay again. But if I go downstairs again during this time and the phone switches to downstairs AP, the network is fine. There isn't any problem If i setup the router downstairs as a universal repeater without the ethernet. But then  i'd lose half the bandwidth. I have tested using two phones oneplus 7 pro and a redmi K20 pro and the issue is consistent.

[Alex Atkin UK]

I'm impressed that roaming works at all, its not something that WiFi does well.  I always leave my SSIDs different so I can manually force which one I'm using for that reason.

[abhijithas]

18 hours ago, Alex Atkin UK said:

I'm impressed that roaming works at all, its not something that WiFi does well.  I always leave my SSIDs different so I can manually force which one I'm using for that reason.

it's always worked fine for me. using the same protocol and encryption on all APs does the trick.

[Donut417]

3 hours ago, abhijithas said:

it's always worked fine for me. using the same protocol and encryption on all APs does the trick.

Not exactly. Roaming consists of 3 standards last I heard. Not all routers/Access points, support every standard. You got lucky, that’s all. 

[abhijithas]

1 hour ago, Donut417 said:

Not exactly. Roaming consists of 3 standards last I heard. Not all routers/Access points, support every standard. You got lucky, that’s all. 

i guess i did get lucky that all of my APs has a wifi roaming standard baked in.. but still,i think it would also need the same security protocols and encryption on all APs. (at least from my experience it is so.)

[Donut417]

38 minutes ago, abhijithas said:

i guess i did get lucky that all of my APs has a wifi roaming standard baked in.. but still,i think it would also need the same security protocols and encryption on all APs. (at least from my experience it is so.)

It does, but the roaming standards do more than make a device move to a new AP. The devices IP info had to be handed off to the next AP. Theoretically without the device disconnecting. 

[Alex Atkin UK]

6 hours ago, abhijithas said:

i guess i did get lucky that all of my APs has a wifi roaming standard baked in.. but still,i think it would also need the same security protocols and encryption on all APs. (at least from my experience it is so.)

I'd certainly question if its actually roaming, or your walls are just so dense that its dropping WiFi consistently enough to feel like it is.

The key with roaming is that all APs talk to each other so that if you move into range of a different AP that would get a stronger signal, you're automatically switched over.  Whereas with normal WiFi your device will cling onto the signal until its too weak to function, even if you are sat next to a different AP with the same SSID.

[abhijithas]

11 hours ago, Alex Atkin UK said:

I'd certainly question if its actually roaming, or your walls are just so dense that its dropping WiFi consistently enough to feel like it is.

The key with roaming is that all APs talk to each other so that if you move into range of a different AP that would get a stronger signal, you're automatically switched over.  Whereas with normal WiFi your device will cling onto the signal until its too weak to function, even if you are sat next to a different AP with the same SSID.

nah that isn't the case because the second AP(downstairs) is at a place where i get 80 percent signal strength of the main router.

and it's seamless that i rarely drop a frame when i'm on a video call and the AP switches as i go downstairs.

The only issue here is finding out why the connectivity gets messed up for a few minutes when the AP is switched to the main router again. I changed my ISP yesterday to a fiber with 20Mbps and now when the connection is glitchy after an AP switch, i'm getting about 1Mbps for few minutes before back to normal. i checked the router's system log and did not find anything suspicious.

[Falcon1986]

3 hours ago, abhijithas said:

-snip-

What are your LAN IP settings on the primary C6 router and the AP?

 

Also, what's your IP lease time and WiFi renewal key time set to on both devices?

[abhijithas]

56 minutes ago, Falcon1986 said:

What are your LAN IP settings on the primary C6 router and the AP?

 

Also, what's your IP lease time and WiFi renewal key time set to on both devices?

Archer c6 at 192.168.0.1 and AP at 192.168.0.2. DHCP (0.101-0.249 pool)on archer with lease time 120 minutes.

I'm sorry i don't know what wifi renewal key time is. I haven't seen such a field anywhere.

 

[Falcon1986]

2 hours ago, abhijithas said:

Archer c6 at 192.168.0.1 and AP at 192.168.0.2. DHCP (0.101-0.249 pool)on archer with lease time 120 minutes.

I’m assuming the subnet mask is the same in both cases: 255.255.255.0.

 

Since the AP has DHCP disabled, you shouldn’t need to specify IP ranges. What LAN IPs are set for DNS and gateway on the AP?

 

Set the IP renewal period to 86400 (1 day local IP lease) or actually assign static IPs to permanent devices bound to their MAC addresses. 

[Aditya Dighe]

On 9/17/2020 at 7:34 PM, Alex Atkin UK said:

I'm impressed that roaming works at all, its not something that WiFi does well.  I always leave my SSIDs different so I can manually force which one I'm using for that reason.

Yes, It also does depend upon manufacturers. Some Chinese manufacturers like Xiaomi, One Plus , and other smartphone manufacturers do seamless roaming. All of my family members have Samsung Devices and Samsung phones typically give uninterrupted connections. They don't do roaming most of the time.

 

How ever , I just tried something which isn't at all recommended ( Keeping both on same channels), I kept both my Routers on same channel, same SSID, same password, same bandwidth, same encryption. Now it does work 90% of time. It does switch to the one with better signal.  Yet only problem still I have, devices don't always connect to or switch to 5Ghz band even though it is in range or better range. 

 

Now only yesterday, I did change it and have same both 2.4G and 5G SSID . Now actually I am going to check over a next few days if it does work any better

[Aditya Dighe]

3 hours ago, abhijithas said:

Archer c6 at 192.168.0.1 and AP at 192.168.0.2. DHCP (0.101-0.249 pool)on archer with lease time 120 minutes.

I'm sorry i don't know what wifi renewal key time is. I haven't seen such a field anywhere.

 

As @Falcon1986 Suggested , do set the Lease time to 1day. Also would recommend you to use Short preamble , I guess you won't have much active devices which were manufactured prior to 2009, so you can go ahead with Short Preamble

[Falcon1986]

4 hours ago, Aditya Dighe said:

How ever , I just tried something which isn't at all recommended ( Keeping both on same channels), I kept both my Routers on same channel, same SSID, same password, same bandwidth, same encryption. Now it does work 90% of time.

It’s not recommended because you’re essentially shooting your own network in the foot, i.e. creating your own wireless interference/noise.

 

If you have free channels on a wireless survey, it would be better to utilize the free channels than to overlap broadcasts. The slowdown will come when each AP’s conected clients get active. Channel width, SSID, WiFi password, encryption, etc. can all be kept the same.

 

The only time this practice might be acceptable is when your wireless spectrum is already crowded (e.g. 2.4GHz), but you’re dealing with a difficult situation to start. In this scenario, it might help to reduce the wireless radio’s power output so that each AP’s signal only barely overlaps.

[Aditya Dighe]

11 hours ago, Falcon1986 said:

It’s not recommended because you’re essentially shooting your own network in the foot, i.e. creating your own wireless interference/noise.

 

If you have free channels on a wireless survey, it would be better to utilize the free channels than to overlap broadcasts. The slowdown will come when each AP’s conected clients get active. Channel width, SSID, WiFi password, encryption, etc. can all be kept the same.

 

The only time this practice might be acceptable is when your wireless spectrum is already crowded (e.g. 2.4GHz), but you’re dealing with a difficult situation to start. In this scenario, it might help to reduce the wireless radio’s power output so that each AP’s signal only barely overlaps.

I agree, this indeed can cause both constructive or destructive interference or both at different scenarios.

 

I just don't have much heavy users, and my PC is connected via Gigabit LAN, Other than that other devices (Around total 15 active) are smartphones and 2-3 smart devices no one usually streams anything. Just once in a while some Video Calls via Whatsapp or Google Duo or Meet. So I needed a seamless roaming.

 

The 2.4 Ghz isn't crowded with many APs but it is full, one of neighbour using Channel 7 , other 1 , & myself using Channel 1. 

 

I have set the channels apart on 5Ghz band. My neighbour is on channel 149 on 5G, another neighbour, their 5Ghz signal barely reach us sometimes (I don't remember their channel no.). So I am using Channel 36 & 56 for my routers at 80Mhz on 5G

 

But I still experience problems with roaming when I set channels apart on 2.4G.  In majority of cases the devices stick to same AP. I know this shall not be a channel issue with roaming, but somehow experienced it.

 

Another thing which I am not getting is the anti-interference feature in my main router. 

 

 

[abhijithas]

On 9/19/2020 at 8:35 PM, Falcon1986 said:

I’m assuming the subnet mask is the same in both cases: 255.255.255.0.

 

Since the AP has DHCP disabled, you shouldn’t need to specify IP ranges. What LAN IPs are set for DNS and gateway on the AP?

 

Set the IP renewal period to 86400 (1 day local IP lease) or actually assign static IPs to permanent devices bound to their MAC addresses. 

i didn't. i said DHCP is on the archer. AP doesn't have a DNS and gateway to be set.

 

i have already tried assigning static ip by binding to MAC. didn't help. 

[Aditya Dighe]

1 hour ago, abhijithas said:

i didn't. i said DHCP is on the archer. AP doesn't have a DNS and gateway to be set.

 

i have already tried assigning static ip by binding to MAC. didn't help. 

 

In DHCP Settings of your main Router, which is your TP link archer, Set an IP Range excluding the range . ( eg set range from 192.168.0.3 ~ 192.168.0.255 )

 

I am assuming that you have removed Iball ibaton 150M wireless-n adsl2+modem router (@192.168.1.1), of BSNL after getting fiber ? Because as per the first post, you had set it in bridge with Archer C6, and in that case Archer C6 won't need PPPOE, 

 

Also if you don't have old devices ( prior to 2009 ), if it is possible in settings , set all router's 2.4 Ghz to 802.11 n mode only. And for 5Ghz you have to see if all 5Ghz devices are compatible with 802.11ac then set it to ac, else to a/n/ac . Because I have an old smart TV from 2014 and it supports 5Ghz band too, but only 802.11a ( The old standard capped at 54mbps )

 

If there are no neighbouring APs , then use 40Mhz bandwidth for 2.4 , else don't because in that case , channels get more wider and interference increases .

 

For 5Ghz Set Channel bandwidth to 40 or 40/80 or 80 Mhz , Mostly you won't have much neighbouring APs on 5Ghz . If there are then 80mhz groups are as follows 36 - 48 channels for 80mhz, another is 52-64 , then 100-112 , 116-128, 132 -144 , 149 -161 . 

 

Further, it could be an issue with CAM Table update.

 

 

 

[Falcon1986]

5 hours ago, abhijithas said:

AP doesn't have a DNS and gateway to be set.

That's weird. How did you specify the static IP of the AP? If you did it on the AP itself, there should be a setting to specify the gateway and DNS server (in your case, it should be the static internal IP address of the Archer).

[Aditya Dighe]

5 hours ago, Falcon1986 said:

That's weird. How did you specify the static IP of the AP? If you did it on the AP itself, there should be a setting to specify the gateway and DNS server (in your case, it should be the static internal IP address of the Archer).

Some Routers have this issue, they need DHCP server to be enabled, and in DHCP server settings their DNS needs to be set to the main router.

Like here on my old router which I use just as a port switch, I keep it off, it works without it. 

 

 If set to None , there are no options

[abhijithas]

11 hours ago, Falcon1986 said:

That's weird. How did you specify the static IP of the AP? If you did it on the AP itself, there should be a setting to specify the gateway and DNS server (in your case, it should be the static internal IP address of the Archer).

DNS and gateway are set for a DHCP server, which is disabled. As Aditya here said it.

[abhijithas]

15 hours ago, Aditya Dighe said:

 

In DHCP Settings of your main Router, which is your TP link archer, Set an IP Range excluding the range . ( eg set range from 192.168.0.3 ~ 192.168.0.255 )

As i said in a previous reply, the range is 0.101-0.249 , which is pretty much the default except it was starting at 0.100 which i had to exclude as i have assigned 0.100 to my PC.

Quote

 

I am assuming that you have removed Iball ibaton 150M wireless-n adsl2+modem router (@192.168.1.1), of BSNL after getting fiber ? Because as per the first post, you had set it in bridge with Archer C6, and in that case Archer C6 won't need PPPOE, 

I'm still running ppoe in the archer. The new connection is using a single GE port Syrotech EPON onu without wifi, which doesn't have routing capabilities. a bridge mode only if you will.

Quote

 

Also if you don't have old devices ( prior to 2009 ), if it is possible in settings , set all router's 2.4 Ghz to 802.11 n mode only. And for 5Ghz you have to see if all 5Ghz devices are compatible with 802.11ac then set it to ac, else to a/n/ac . Because I have an old smart TV from 2014 and it supports 5Ghz band too, but only 802.11a ( The old standard capped at 54mbps )

 

 

If there are no neighbouring APs , then use 40Mhz bandwidth for 2.4 , else don't because in that case , channels get more wider and interference increases .

i have played around with the channel bandwidth.. didn't help. but i will try changing to 802.11n on both APs and give it a try.

Update: didn't work either.

Quote

Further, it could be an issue with CAM Table update.

 

 

 

what's that and how does that affect wifi handoff.

[Aditya Dighe]

41 minutes ago, abhijithas said:

15 hours ago, Aditya Dighe said:

Further, it could be an issue with CAM Table update.

what's that and how does that affect wifi handoff.

This is a bit complicated to explain, but in short - When your device roams from one access point to another , the MAC address table ( CAM Table - Content Addressable Memory Table stores MAC addresses and IP addresses assigned ),  updates that the port / Access Point from which the client is connected is changed, this happens as a client sends a broadcast or unicast packet on the network.  

 

Because basically your cascaded router ( Iball one ) is a router working as a switch and an access point, It may not be updating its own table that the client is indeed disconnected, causing a conflict that the client is connected to both the routers. And After 2-3 minutes after the cam table updates and the problem gets resolved. 

 

Apparently, if this seems to be a problem, then the only thing you can do is try using another old/new firmware with both Iball and TP Link. Old firmware may have security issues though. .

 

I will try if I get anything other than that can be done. 

 

Here I found another user, who faced a similar issue. Although there is no solution there, you can for now, try updating the router firmware. 

 

[abhijithas]

9 hours ago, Aditya Dighe said:

This is a bit complicated to explain, but in short - When your device roams from one access point to another , the MAC address table ( CAM Table - Content Addressable Memory Table stores MAC addresses and IP addresses assigned ),  updates that the port / Access Point from which the client is connected is changed, this happens as a client sends a broadcast or unicast packet on the network.  

 

Because basically your cascaded router ( Iball one ) is a router working as a switch and an access point, It may not be updating its own table that the client is indeed disconnected, causing a conflict that the client is connected to both the routers. And After 2-3 minutes after the cam table updates and the problem gets resolved. 

 

Apparently, if this seems to be a problem, then the only thing you can do is try using another old/new firmware with both Iball and TP Link. Old firmware may have security issues though. .

 

I will try if I get anything other than that can be done. 

 

Here I found another user, who faced a similar issue. Although there is no solution there, you can for now, try updating the router firmware. 

 

Hmmm.. so it's an issue with the archer in router mode it seems. I have tried using a different AP (another modem/router i had lying around) to no help.

 

I want to but can't downgrade the firmware on the archer. it's on the latest version and they've supposedly disabled firmware downgrade with this latest update for whatever reasons. 

 

OpenWRT is the only thing left to try at this point. Maybe I'll give that a shot..

[Aditya Dighe]

Yes that's weird, at majority of times, clicking upgrade button and then giving an old firmware file would downgrade it but seems like they check with the old and new versions on firmware files. 

 

Or you can also install OpenWRT and then flash back the router firmware. Of course OpenWRT will be a better choice.

 

--------------------------------------------------Just for data Safety, ignore if not important ---------------------------------------------------------------------------------------------

 

Maybe, you can try one more thing, disable router's access to the tp-link website and servers using Open DNS. 

I disabled it.... Chinese Routers.... my Tenda router access the domain api.cloud.tenda.com.cn something about 1200 times a day as per Open DNS Reports, I disabled it via Cisco's Open DNS. While cloud.tenda.com.cn just 2 times in a day.

 

To Check which websites it accesses, before 12 o clock at night keep Open DNS Ready, and at night, turn off WIFI from your router interface, disconnect wired lan devices . And at morning ... as Open DNS shows logs upto 1 hr back.. check which websites it accesses in the morning.  You will also get which- are the ones which it uses for update purpose.

 

 

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[abhijithas]

21 hours ago, Aditya Dighe said:

 

 

Because basically your cascaded router ( Iball one ) is a router working as a switch and an access point, It may not be updating its own table that the client is indeed disconnected, causing a conflict that the client is connected to both the routers. And After 2-3 minutes after the cam table updates and the problem gets resolved. 

 

 

Also, i doubt this is the case because the problem persists even if i turn off or disconnect the AP from the archer right after a handoff. so it is definitely something to do with the archer.