Strange behavior of MESH system?

[Ola Malmstrom]

One of my neighbors has an ASUS mesh system that interferes with my ASUS router.

I can see his client SSID using the tool analiti - the MAC address is 24:4B:FE.xx.xx.D4

I can also see his backhaul band, but the SSID's are hidden. The MAC addresses are 24:4B:FE.xx.xx.D7 and 24:4B:FE.xx.xx.D8.

He seems to be using the 5 GHz band with control canal 116(80) as backhaul.

This interferes with me. So I changed my 5 GHz channel to 100(80). The result was that his hidden SSIDs followed me - 100(80).

I tried again and went back to 116(80). So did his system.

Does anyone know why his mesh system seems to change control channel at exactly the same time as I? If I set my control channel to Auto, the same thing happens. We are on the same channels and bandwidths.

Another strange thing is that he seems to have the same signal strength as I have - -57dBm. Which is very strange since there are two brick walls between us as well as about 40 meters (roughly 120 feet). Is there a bug in the analiti tool?

 

[Ola Malmstrom]

One of my neighbors has an ASUS mesh system that interferes with my ASUS router.

I can see his client SSID using the tool analiti - the MAC address is 24:4B:FE.xx.xx.D4

I can also see his backhaul band, but the SSID's are hidden. The MAC addresses are 24:4B:FE.xx.xx.D7 and 24:4B:FE.xx.xx.D8.

He seems to be using the 5 GHz band with control canal 116(80) as backhaul.

This interferes with me. So I changed my 5 GHz channel to 100(80). The result was that his hidden SSIDs followed me - 100(80).

I tried again and went back to 116(80). So did his system.

Does anyone know why his mesh system seems to change control channel at exactly the same time as I? If I set my control channel to Auto, the same thing happens. We are on the same channels and bandwidths.

Another strange thing is that he seems to have the same signal strength as I have - -57dBm. Which is very strange since there are two brick walls between us as well as about 40 meters (roughly 120 feet). Is there a bug in the analiti tool?

Does anyone have an idea or two what's going on?

Maybe I should provide some more details: I am testing a Zenwifi Pro XT12 as a router and another Zenwifi Pro XT12 as an AP with wired backhaul (not 2.5 mbit/s yet but maybe later). I would like to try the 5-2 band for clients instead of the 5-1 band to make use of the extra transmit power available there (1000mW as opposed to 200 mW) as well as less interference from neighbors.

However it seems like there are issues (or maybe "features"?) with the 5-2 band that creates interference somehow.

Today I tried again. Changed my control channel to 140 on a PC connected through wire. Checked the result on a portable PC connected through wifi. The second my router started transmitting on channel 140, the neighbors stations switched to the same channel. I changed back to channel 36, and as soon as that was up again, the neighbors stations were back at channel 116.

What is going on?

 

[L&LD]

Auto Channel. Works great. Has never given me the best performance.

Wireless routers are at their best when sharing bandwidth by being on the same wireless channel as all others in the same vicinity. The reason is because they need to communicate with the other routers to take turns (share) the time slices most effectively. But this behaviour doesn't give specific environments the best performance.

That is why you can try to extend your testing to 24 hrs +. His router may switch away from your settings.

Or, ask your neighbour to use a manual Control Channel (nicely).

 

[sfx2000]

Another strange thing is that he seems to have the same signal strength as I have - -57dBm. Which is very strange since there are two brick walls between us as well as about 40 meters (roughly 120 feet). Is there a bug in the analiti tool?

Hmmm.. wonder if there is a bug in the scanner tool - sounds like you're chasing yourself across the channels..

 

[tgl]

Hmmm.. wonder if there is a bug in the scanner tool - sounds like you're chasing yourself across the channels..

Indeed. Occam's razor says that those hidden SSIDs are yours not your neighbor's. The non-global MAC addresses can make this a bit hard to diagnose, especially if the other router is sharing most of the MAC prefix bits with yours. Try turning off your router altogether, or at least turn off its wireless backhaul support, and see if those hidden SSIDs go away.

 

[Ola Malmstrom]

Hi all,

thank you for your comments. I have done as you suggested. I turned off the router and AP for a couple of days and went to a Bruce Springsteen concert about 6 hours away for a couple of days ;-).

There is no change - the neighbors hidden network is still there - now on channel 100(80). His stations are there there all the time, no matter if my router and AP are switched off or not.

So tried again - set my 5-2 channel on 128(80). Immediately one of his stations followed me and changed from 100(80) to 128(80). I'll leave it like this until tomorrow to see what happens.

Note: I have checked with different tools both on PC and android.

I am reluctant to speak to my neigbor since we have had some issues before and I don't want him to feel accused or anything like that.

My conclusion is that we are both using equipment from Asus that somehow tries to connect.

I guess the only way is to try to understand this strange behavior is to talk to him nicely and blame Asus for not having updated their FW.....

 

[Ola Malmstrom]

So 1.5 days later I'm at 116(20) this morning. So is my neighbor.......

Just occurred to me that these are DFS channels. Most likely both our routers have changed the channels due to airport or weather radar interference. There is an airport about 45 kms away (about 30 miles)......

 

[bbunge]

So 1.5 days later I'm at 116(20) this morning. So is my neighbor.......

Just occurred to me that these are DFS channels. Most likely both our routers have changed the channels due to airport or weather radar interference. There is an airport about 45 kms away (about 30 miles)......

If you were being hit by RADAR, you should be in the 36 to 48 channel range. You might try turning off the DFS channels and using the lower channels. I understand that in some locals the DFS allows for higher transmit power but that could work against you. Same with forcing 160MHz.

 

[Ola Malmstrom]

Good idea. Thanks! I'll reduce the transmit power to see what happens. Using the lower channels works fine, but I would like to see if there is any difference in range using the 5-2 band.

 

[bbunge]

I have tried many WIFI settings over the years working to avoid conflict with other WIFI routers. The assumption has always been to use a channel different from the neighbors.
Knowing that Ethernet uses Carrier Sense, Media Access, Collision Detection as compared to WIFI which uses Carrier Sense, Media Access, Collision Avoidance, using different WIFI channels seemed the prudent thing to do. I've not noticed that routers may choose to use the same channels as nearby routers until you mentioned it and I did a quick "test" this morning and put my 5 GHz on auto channel (no DFS). The 5 GHz started out on channel 36 @ 160 MHz but within a short time switched to channel 153 @ 80 MHz. Checking nearby routers I discovered the strongest neighbor signal was on channel 153. The neighbors router is a Netgear.
So, did the router switch tothe neighbors channel to better detect WIFI collisions? Maybe one of the engineers in the group has some insight into this...

 

[tgl]

Strength of the competing signal isn't all that much of a factor. What is a factor (given a well-designed router) is the total airtime usage in each channel across all visible SSIDs. Maybe you have a lot of neighbors using the 36-48 band and fewer-but-closer ones using 149-161? It could make sense then to switch to something in the high band, even if there is a stronger signal.

Some APs will report what they measure as the channel utilization percentage in their SSID beacon frames --- meaning you can see it even if not logged into that SSID. This is really useful information when you're trying to understand a situation like this. (Of the wifi scan apps I've used, WiFi Explorer and WiFi Scanner will report channel utilization, but NetSpot Pro doesn't seem to have an option for it :-( ...)

 

[bbunge]

Maybe you have a lot of neighbors using the 36-48 band and fewer-but-closer ones using 149-161? It could make sense then to switch to something in the high band, even if there is a stronger signal.

I only have two neighbors on channel 36-48 and they are lower than the closest neighbor.
Netgear ch 153 -68dBm
Netgear ch 48 -87 dBm

 

[Viktor Jaep]

Indeed. Occam's razor says that those hidden SSIDs are yours not your neighbor's...

@tgl -- I love Occam's Razor... it's like Confucius, but more logical... Just opened my big book of Confucius sayings, and found one that gives some real solid advice here:

Confucius says, "He who seeks true connectivity must first find his own wireless path. Like a hidden spring in a vast desert, let your SSID remain unseen, for it is the oasis of your digital realm. Do not covet your neighbor's WiFi, for true harmony lies in the virtuous pursuit of your own signal strength."

 

[tgl]

I only have two neighbors on channel 36-48 and they are lower than the closest neighbor.

Right, but how much traffic are those various neighbors generating? It's really hard to tell about this without that information.

 

[Ola Malmstrom]

So, finally....

Kept the control channel to 128(80) and reduced the transmit power from max to balanced (22 dbm). Initially, on Sunday, the neighbors channel was the same as mine. However, now on Wednesday, his has changed to 100(80) but my channel now reigns supreme on 128(80).

Reducing the power seems to have done the trick. Thanks all for your comments!