NWA210AX MAC randomly changes

kevindd992002

I have DHCP reservation setup for my Zyxel AP's. Yesterday, 3 out of my 9 AP's changed IP for some reason and when I checked the DHCP server, the MAC address shown by 3 of the AP's are different (no manufacturer OUI identifiable) which is the reason why the DHCP server gave out an IP from its pool. I can still access the AP through its IP and Nebula shows them as online but this breaks things like RADIUS authentication because the client (AP) changes IP. Here's a sample MAC that the DHCP server sees in the DORA process from one the AP's:

da:28:e5:9d:09:20

Why is this happening? @Zyxel_Kay

kevindd992002

Here are all the bogus MAC's that are on the DHCP lease logs:

Restarting the AP's fixes the problem. I don't know how to recreate the issue but the only thing I did earlier before this manifested is that I restarted the DHCP server.

Zyxel_Kay

Hi @kevindd992002

To prevent the issue with DHCP reservations and MAC address changes, we recommend setting a static IP directly on each AP through Nebula Control Center (NCC). You can configure this by navigating to Site-wide > Devices > Access Points > [Select AP] > Status and assigning a static IP for each access point.

If you've already configured a static IP via NCC and are still encountering this issue, please enable Zyxel Support access and provide your Nebula organization and site name so we can investigate further.

kevindd992002

https://community.zyxel.com/en/discussion/comment/70672#Comment_70672

Sorry, but that is not a solution. That is a workaround. I don't want to set a static IP. DHCP reservation should work just fine and MAC addresses should NOT change whatsoever. This is the first time I saw access points changing MAC addresses. I always use DHCP reservations in any network deployment that I have since they are easier for me. So what is our next step?

Zyxel_Kay

Hi @kevindd992002

Could you please enable Zyxel Support access and provide your Nebula organization and site name? We would like to review the system logs of the affected APs.

kevindd992002

Done.

Organization: Kevin's Infrastructure

Site Name: Casa MF

Zyxel_Kay

Hi @kevindd992002

After reviewing your site and device logs, we found that your APs experienced an uplink connectivity issue, which caused them to switch to repeater mode. Under normal circumstances, the AP will use its physical MAC address to request DHCP. However, when it enters repeater mode due to a loss of uplink connection, it will use the WDS interface MAC to request a DHCP IP.

We noticed that your APs are mostly connected via Ethernet. If Smart Mesh is not required in your environment, we recommend disabling it on the site to prevent this issue from recurring.

kevindd992002

https://community.zyxel.com/en/discussion/comment/70845#Comment_70845

I see. If I reboot my DHCP server, then that will really result into an uplink connectivity issue on the AP's, correct? What does Smart Mesh do and where is it used for?

Zyxel_Kay

Hi @kevindd992002

Yes, based on the logs, rebooting your DHCP server can indeed result in an uplink connectivity issue for the APs.

The Smart Mesh feature is typically used to extend WiFi coverage in areas where it’s difficult to run an Ethernet cable. You can refer to this article for more information on Smart Mesh use cases:
What are the use cases of Smart Mesh Network in various scenarios?

Since your APs are consistently connected via Ethernet, Smart Mesh may not be necessary in your setup. We recommend disabling it to prevent the issue from recurring.

kevindd992002

https://community.zyxel.com/en/discussion/comment/70852#Comment_70852

Ok. I just disabled Smart Mesh. How about Etherner Failover, should I enable that or not?

Zyxel_Kay

Hi @kevindd992002

The Ethernet Failover feature controls how the AP changes roles based on connectivity. Here's the design mechanism:

• When enabled, a wired AP will automatically switch from root AP to repeater mode if it cannot reach the site's gateway.
• When disabled, the AP will only switch to repeater mode if its uplink Ethernet cable is physically disconnected.

For your setup, I recommend keeping it disabled.