Assistance Needed: Configuring VLANs, DHCP Relay, and Port Modes on Cisco and ZD1200 Devices

[Awais]

Please guide me on the following case: I have configured RADIUS on 172.16.10.31, and users will receive dynamic VLANs from it—for IT, VLAN 11 and for Finance, VLAN 14. Currently, my DHCP server is configured on 172.16.10.29, and I have configured the relay on the ZD1200 accordingly. My AP R510 is connected to a Cisco 2960 access switch, and the ZD1200 wireless controller is also connected to the same switch. When I configure the port of the Cisco 2960 in switchport mode access for controller, the connectivity between the AP and controller is established. However, when set to trunk, they lose communication with each other. AP connected to switch with port mode trunk is working fine.

Similarly, when I keep the Cisco switchport mode in access for controller, users authenticate via the AAA RADIUS server correctly but cannot find the DHCP server. The DHCP server is behind a firewall and traffic to it passes through a core switch where the IP helper command is already defined for DHCP.

What should I do? What should be the port mode for connectivity between the Cisco switch and ZD1200, and between the Cisco switch and AP R510? What should the Ethernet port settings be within the ZD1200 and AP R510? Keep in mind that users should get dynamic IPs from their respective pools (11 for IT and 14 for Finance) using the single SSID name "ZDTEST".

[bruno_andrade · Accepted solution]

Hi Awais,

Are your WLANs configured in tunnel mode? The ZD DHCP relay option only functions with tunneled WLANs. If you are tunneling traffic, ensure that the switch ZD interface is in trunk mode to allow all user VLANs, while keeping the native VLAN configuration in the VLAN used by the ZD for management.

If you are not using tunneling, you may leave the ZD in access mode and set the APs to trunk mode, allowing all user VLANs. Make sure to set the native VLAN for the AP management network.

[Awais]

Hi Bruno,

It worked. Thank you for the solution. I opted for the second option; I removed the DHCP relay as I was not using tunnel WLANS. The APs are connected to a trunk port to carry multiple VLANs that are assigned dynamically. The ZD is on an access port, and I set the management VLAN for AP management.

PS: I configured the management VLAN in standalone mode before joining to ZD. Thankfully, it worked for the above scenario.