Specific VAPs (one SSID on one radio) randomly stops bridging (some?) traffic

I’m getting ready to open a ticket (have to wait for problem to reoccur, then collect techsupport, etc.), but while I work on this, want to know if anyone else is experiencing a problem similar to this & whether it might be a well-known issue with known workarounds…

Has anybody ever run into an issue with e-series cnPilots (in this case, e410, but I’m guessing it’s not limited to these) where, seemingly at random, a single SSID on a single radio (so, essentially, a particular VAP) will simply stop forwarding broadcast traffic (which in turn completely breaks essential things like DHCP & ARP)?

When it happens, other SSIDs on the same radio are unaffected (can ask the same computer to connect to different SSID that’s on the same VLAN, and it works perfectly), as is that same SSID on the other radio if that SSID is configured to exist on both bands (so if it happens on 2.4GHz, 5GHz will be okay, or vice-versa). Rebooting the Pilot will correct the problem…for a while (few hours, few days, etc.).

Particular customer of ours (coffee shop) started experiencing this problem a couple of weeks ago, and it’s driving both me and them mad. They’re also a particularly loud customer, so it’s been extremely frustrating. I’m this close to ripping the Pilots out and replacing with something non-Cambium at this point, frankly.

The fact that it’s happening in a well-trafficked location like a coffee shop makes me think that the trigger to the bug might have something to do with either the number of absolute associations/disassociations, or the frequency of assoc/disassoc (which would also explain why it’s only affecting the SSID that their customers / the public use). But it’s odd that they haven’t had problems up until very recently, which makes me wonder if something in “the environment” changed, like perhaps there’s some badly-behaving WiFi client that’s doing something non-kosher that the Pilot is responding poorly to.

Enabling Unicast DHCP option on the SSID does not work around the problem, and clients still cannot receive a DHCP lease while Pilot is in this funky state even with that option enabled. I have updated them to with no change, but am hesitant to go beyond that to 6.x given some of the other known issues surrounding that branch that are being discussed in other threads.

Anyone? Bueller?

I have just opened support request #314116 FWIW.

In 4.x, I had devices on WLAN 2 stop passing traffic.

Updating to 6.x opened a different can of worms.

The new releases candidate… Addressed my Roku problems. But now people are bitching that wifi calling is failing. Images on websites are not loading. Etc.

Confirmed them here at my house.

Units are going back in the box again.


Not what I wanted to hear re: the current release candidate.

Symptoms again sound like AP is just trying to be too “smart” for its own good. Again I will state that there needs to be a way to definitively turn off having traffic flow through Linux kernel connection tracking.

After an email from Gary I decided to give it another shot.

I think my problems with connectivity maybe related to the SSID using EPSK.

Not sure yet… however… the problems I was seeing here, seemed to have stopped, when I moved everything off that SSID.

Hi Nathana,

Is it possible to provide remote access to your setup when the issue is happened. If yes, please share me the details on my email id : ashok.kumar@cambiumenetworks.com


Thank you. I have sent you e-mail, and also CC:d you on the active support ticket.

I have received the email. Thanks for sharing the remote setup details.

I want to publicly thank Ashok for his time today…he and a colleague spent a solid 2 hours on a Teams call with me trying to debug the issue. At this point, they have seen the problem happening for themselves, and have some packet captures that both they took from the AP & that I took from local clients on-site. So though still no clear answers on what is happening, or what is even the trigger, I am optimistic that this bug will eventually get found and addressed.


Good to hear on Ashok work

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My issue is specific too EPSK enabled SSID.

Support files sent.