[Slate 7] WLAN devices lose connectivity to each other (Ping timeouts) - resolved by toggling Client Isolation

Routers
1

Hello.

I am using a GL-BE3600 "Slate 7" on the latest firmware (4.8.1 release8) in standard Router mode. I use it as a router for a small home network, so it’s running 24x7 with about 10-20 clients. All devices are using Wi-Fi, the LAN port currently goes unused.

I am experiencing a recurring issue where devices on the same wireless network eventually lose the ability to communicate with each other. For example, my laptop cannot ping my Apple TV, even though both are connected to the same Wi-Fi SSID and have valid IP addresses.

Symptoms:

  • Device-to-device communication (LAN) fails after some time (I have not identified a particular duration).

  • Pings between devices result in timeouts.

  • Internet connectivity on these devices remains functional; only local peer-to-peer communication is affected.

  • Pings from the router to both devices do work as expected (tested using SSH).

  • Rebooting the router in software does not consistently fix the issue.

Manual workaround found:
I have found that logging into the router web panel, enabling "Isolate Clients", applying it, and then immediately turning it back OFF resolves the issue instantly. This restores connectivity between my devices.

Question:
Has anyone else experienced this specific loss of local device connectivity? Is there a confirmed bug that is being tracked for a future firmware update, or is there a permanent configuration fix (like a specific firewall or bridge setting) that prevents this corruption from happening in the first place? Or has anyone found a workaround that can be automated to fix it?

Thank you in advance.

3

Hi,

This behavior is a bit unusual, and we have not encountered similar reports before.

When the issue occurs, please SSH into the router and run the following commands to help verify the status:

uci show | grep isolate
grep ap_isolate /var/run/hostapd*.conf
wifi status | grep  -v 'key\|macaddr'

In addition, please confirm the following:

  1. The client device is connected to the Main Wi-Fi network rather than the Guest Wi-Fi network.
  2. AP Isolation is disabled in GL UI → Network → LAN.
  3. No wireless-related settings have been added or modified via SSH or LuCI.
4

Thanks for responding. I will collect that info the next time it occurs, though it might be days to weeks until that happens.

In the meantime I can confirm:

  1. The devices are using the main wi-fi network (I don’t use the Guest network functionality and it is turned off).
  2. AP Isolation is turned off, except temporarily during the workaround I described.
  3. I am not aware of any settings added/modified in SSH or LuCI.
5

Thank you for the update.

If possible, please also share your device with us via GoodCloud by following the tutorial below, and let us know once the fault happen without using workaround to fix it. This will allow us to try to diagnose the issue and test potential fixes within a single occurrence, rather than waiting for the problem to reappear.
Technical Support via GoodCloud - GL.iNet Router Docs 4

Please send us the device’s MAC address and WebUI login password via private message so we can find and access the device.

image
image632×233 19.1 KB

6

The problem has reoccured today and I've noticed some further symptoms. Sorry, but I do not wish to provide remote access to the device.

I don't think client isolation is the direct problem anymore, but none the less here is the outputs of the commands mentioned before (I have redacted my SSID for privacy):

root@GL-BE3600:~# uci show | grep isolate
gl-black_white_list.lan.ap_isolate='0'
gl-black_white_list.guest.ap_isolate='0'
gl-black_white_list.guest.wan_isolate='0'
network.@device[1].isolate='0'
network.lan.isolate='0'
network.guest.isolate='0'
wireless.wifi2g.isolate='0'
wireless.wifi5g.isolate='0'
wireless.guest2g.isolate='0'
wireless.wlanmld2g.isolate='0'
wireless.wlanmldguest2g.isolate='0'
wireless.guest5g.isolate='0'
wireless.wlanmld5g.isolate='0'
wireless.wlanmldguest5g.isolate='0'
root@GL-BE3600:~# grep ap_isolate /var/run/hostapd*.conf
/var/run/hostapd-wlan0.conf:ap_isolate=0
/var/run/hostapd-wlan02.conf:ap_isolate=0
/var/run/hostapd-wlan1.conf:ap_isolate=0
/var/run/hostapd-wlan12.conf:ap_isolate=0
root@GL-BE3600:~# wifi status | grep  -v 'key\|macaddr'
{
	"wifi0": {
		"up": true,
		"pending": false,
		"autostart": true,
		"disabled": false,
		"retry_setup_failed": false,
		"config": {
			"channel": "auto",
			"hwmode": "11beg",
			"country": "DE",
			"txpower": 30,
			"random_bssid": 0,
			"band": "2g",
			"htmode": "HT40",
			"legacy_rates": false,
			"noscan": "0",
			"noscan": false,
			"disabled": false
		},
		"interfaces": [
			{
				"section": "wifi2g",
				"config": {
					"device": "wifi0",
					"mode": "ap",
					"ssid": "REDACTED",
					"encryption": "psk2+ccmp",
					"wds": true,
					"isolate": false,
					"hidden": false,
					"ifname": "wlan0",
					"sae": true,
					"network": [
						"lan"
					],
					"mode": "ap",
					"isolate": false,
					"disabled": false
				},
				"vlans": [
					
				],
				"stations": [
					
				]
			}
		]
	},
	"wifi1": {
		"up": true,
		"pending": false,
		"autostart": true,
		"disabled": false,
		"retry_setup_failed": false,
		"config": {
			"channel": "auto",
			"hwmode": "11bea",
			"country": "DE",
			"txpower": 30,
			"random_bssid": 0,
			"band": "5g",
			"htmode": "HT160",
			"channels": [
				"36,40,44,48"
			],
			"require_mode": "ac",
			"disabled": false
		},
		"interfaces": [
			{
				"section": "wifi5g",
				"config": {
					"device": "wifi1",
					"mode": "ap",
					"ssid": "REDACTED 5G",
					"encryption": "ccmp",
					"wds": true,
					"isolate": false,
					"hidden": false,
					"ifname": "wlan1",
					"sae": true,
					"network": [
						"lan"
					],
					"mode": "ap",
					"isolate": false,
					"disabled": false
				},
				"vlans": [
					
				],
				"stations": [
					
				]
			}
		]
	}
}

The new symptoms I've found are that ARP requests aren't reaching their destination. I've used tcpdump on a source host to determine ARP requests are being sent, tcpdump on the router shows the ARP request is received on the router, but tcpdump on the destination host does not show it being received.

Manually adding ARP table entries on two hosts enables them to communicate with each other as would be normal.

I have a mix of Apple devices and linux hosts. Apple devices seem to be affected more often, but I've been able to produce the same problem between two linux hosts as well. However, at the same time some combination of hosts do not seem to be affected -- they can recover from me manually deleting entries from their operating system ARP table.

7

If the issue is ARP-related, it is commonly associated with client devices failing to properly wake from sleep and respond to broadcast or multicast traffic.

To troubleshoot, please try the following:

  1. In LuCI → Network → Wireless, click Edit next to the relevant SSID.

    image
    image1002×600 49.9 KB

  2. Confirm that WMM mode is enabled (this is required for many power-save and multicast-related features).

    image
    image901×784 36.4 KB

  3. If WMM is already enabled, open Advanced Settings and enable Multi To Unicast, which can improve compatibility with devices that do not reliably handle multicast traffic.

    image
    image902×611 30.8 KB

After applying the changes, please test again to see if the behavior improves.

8

Thank you for your response. I've just gotten around to trying this.

WMM mode was already enabled, and just now I've turned on "Multi To Unicast". I'll monitor over the next 1-2 weeks for whether the problem reoccurs.

9

Thanks for the update. Looking forward to your test results.

10

Hi again. I'm glad to say the problem hasn't reoccured to-date since enabling "Multi to Unicast" in my last post.

Thanks for your help, @will.qiu.

1 Like