Does not switch backup dhcp with wifi from WLC 5508

[Electronic20]

Hi Community,

I have a WLC 5508, it has a WIFI defined on vlan 19, and it has a vlan 19 interface with IP on the same controller:

DHCP principal with IP 10.51.0.200 if it works.
But when we switch the secondary DHCP 10.51.132.200, it does not assign DHCP at the WIFI level, operational secondary DCHP is validated.

It is observed in the WLC that has this option enabled:

In addition, the user who connects via Wi-Fi and with the main DHCP active, appears as DHCP Server 1.1.1.1 and not 10.51.0.200

Would it have something to do with enabling the DHCP proxy, so that the DHCP secondary does not operate or is not assigning IP?

[Flavio Miranda]

Hi @Electronic20 

 The 1.1.1.1 is the WLC´s Virtual interface and it is the expected behavior as the DHCP proxy is enabled.  When proxy is enable, the WLC is the client for DHCP and the WLC will be the DHCP server for wireless. 

 You need to make sure you have the IP add  10.51.132.200 added to the helper-address on your core and if the WLC is able to reach this IP address from management interfafce.

[Electronic20]

Hi @Flavio Miranda 

In the sw

itch core, if you have configured the ip helper 10.51.0.200 (DHCP Principal) and 10.51.132.200 (DHCP Backup) for vlan 19 and if you have connectivity (ping) from the WLC to the 2 DHCPs

These are the interfaces that the WLC has

Another detail is that when the DHCP principal 10.51.0.200 is turned off and the backup DHCP is turned on, 10.51.132.200 does not assign IP to the Wi-Fi network but does assign IP to the wired network.

Could the proxy enabled on the WLC have something to do with it? since 2 DHCP servers are being managed, on the vlan 19 interface of the WLC.