Multi-AP deployment managed by USG110, 2 out of 32 APs not giving DHCP for a single SSID

SINC

We have a 32 AP school network, managed by a USG110. There are two SSIDs, one for Staff and one for Students.

The Student SSID is mapped to a VLAN on the router, and we have the same VLANs set up on the Zyxel managed switches.

DHCP for both networks are handled by the USG110.

Out of all 32 APs, only 2 consistently fail to assign DHCP addresses for stations on the Student SSID, but assign addresses for the Staff network just fine.

If we move to any of the other 30 APs, we are able to get a DHCP address for the Student network.

The USG110 was on firmware 4.25, but we've updated it ot 4.32 with no change.

The APs are all on firmware 5.00(AAZY.5)

In the Log, the USG110 shows that it offers a DHCP address to the station, but never receives an ACK.

The APs are all NWA5123-ACs.

Zyxel_Joslyn

Hi @SINC

Here is the name which I will call in the later content.
2 Issued APs: issuedAP
30 worked APs: workedAP

Would you like to swap the switch ports of the issuedAP and workedAP and have a test?
Step:
Connect issuedAP to the switch port of workedAP, and connect workedAP to the switch port of issuedAP.
After Step. 
1. if the station cannot get IP address from the workedAP with SSID Student, please have a look for the switch setting.
2. If the stations can get IP address from the workedAP with SSID Student, but the station cannot get IP address from the issuedAP with SSID Student, please help to collect the diaginfo of the issuedAP and provide it for us to analyze.
Thanks.

Joslyn

RB_P5

Hi @SINC

Did you get anywhere with this issue? I'm having the exact same problem, however the firewall is a Cisco Meraki MX84.

Thanks

CrazyTacos

Which PVID are configured on the zyxel switch ports connecting to these two APs? The student VLAN or staff VALN?

Connect a device under the student SSID and check the mac address table of your switch. That should give you an idea on which settings may be incorrect.