DHCP issue with wireless access points on VLAN

[niwmik]

I have the following network setup and everything besides the dhcp issue works as it should. I have 2 vlan's separated from each other with Internet access. All hardwired computers do not have any issues with DHCP. The issue I'm having is that some wifi clients going through either wireless access points are not able to get an IP from the DHCP server. Looking at the RT-AC68P log

Jul 25 17:03:45 dnsmasq-dhcp[8341]: DHCPDISCOVER(br0) 18:3a:2d:bd:da:70
Jul 25 17:03:45 dnsmasq-dhcp[8341]: DHCPOFFER(br0) 192.168.1.103 18:3a:2d:bd:da:70
Jul 25 17:03:48 dnsmasq-dhcp[8341]: DHCPDISCOVER(br0) 18:3a:2d:bd:da:70
Jul 25 17:03:48 dnsmasq-dhcp[8341]: DHCPOFFER(br0) 192.168.1.103 18:3a:2d:bd:da:70
Jul 25 17:03:56 dnsmasq-dhcp[8341]: DHCPDISCOVER(br0) 18:3a:2d:bd:da:70
Jul 25 17:03:56 dnsmasq-dhcp[8341]: DHCPOFFER(br0) 192.168.1.103 18:3a:2d:bd:da:70
Jul 25 17:04:11 dnsmasq-dhcp[8341]: DHCPDISCOVER(br0) 18:3a:2d:bd:da:70
Jul 25 17:04:11 dnsmasq-dhcp[8341]: DHCPOFFER(br0) 192.168.1.103 18:3a:2d:bd:da:70

I see that there is a DHCPDISCOVER, DHCPOFFER loop and the wifi client does not make DHCPREQUEST. This didn't happen before I included the smart switch. The odd part is that this seems to only happen to new wifi clients trying to get an IP. Any wifi clients that were on the network before the smart switch was added do not have this issue. My best guess is either the smart switch or wireless access points are not relaying the DHCPOFFER.

 

[ColinTaylor]

What make/model/firmware are the wireless access points running?

 

[niwmik]

The 1st wireless access point is a UniFi AP-AC-Pro with firmware 3.9.27.8537. I'm using UniFi Controller 5.6.39.

The 2nd wireless access point is a wireless router re-purposed as a wireless access point. It is a DIR-850L with firmware 1.12WW.

 

[coxhaus]

I can't tell how your network is setup. What are the IPs of your VLANs? How is your router setup. I guess it is the DHCP server. There is not enough key information to figure this out.

The only thing which comes to mind is when a PC requests an IP address it is a broadcast which is limited by a VLAN because the PC does not know where the DHCP server is. The purpose of a VLAN is to limit broadcast domains. Once a PC has an IP address it knows where the DHCP server is so it is directed traffic. Do you have a DHCP helper relay setting which directs the broadcast to the DHCP server not set?

PS

I assume the wireless devices are defined without VLAN tags. Otherwise since your wireless devices pass through an unmanaged switch there is a chance the unmanaged switch is deleting the tagged bits for VLANs if you have the VLANs defined to the wireless devices. Maybe move your wireless APs to the smart switch and define the tags to the wireless APs. I assume you are not using the wireless on the router.​

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[chadster766]

Did you configure the router with a DHCP Server for VLAN1 and VLAN2 with different IP Subnets?

Did you configure the ports that connects the router and the smart switch as truck ports with PVID as VLAN1 and tagged VLAN2?

Did you configure the smart switch switchports that connect to the unmanaged switches with one as an Access port with PVID VLAN1 and one as an Access port with PVID VLAN2?