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More dynamic interfaces in the same VLAN



I would like to add another interface to my WLC and add it to the group interface to extend my subnets for guest users in anchor controller. Unfortunately when I tried to add another interface in different subnet but in the same VLAN, controller refuse me to create such interface. (warning windows pop up: This VLAN ID has been set on some other interface. Please try again.)


Is there any possibility to do this? Do I really have to add interface in the different VLAN?






To expand the vlan you will need to make the original interface on the WLC bigger or add additional vlans and tie them into a interface group. 

"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
Cisco Employee

Dynamic Interface

Dynamic interfaces, also known as VLAN interfaces, are created by users and designed to be analogous to VLANs for wireless LAN clients. A controller can support up to 512 dynamic interfaces (VLANs). Each dynamic interface is individually configured and allows separate communication streams to exist on any or all of a controller’s distribution system ports. Each dynamic interface controls VLANs and other communications between controllers and all other network devices, and each acts as a DHCP relay for wireless clients associated to WLANs mapped to the interface. You can assign dynamic interfaces to distribution system ports, WLANs, the Layer 2 management interface, and the Layer 3 AP-manager interface, and you can map the dynamic interface to a backup port.

You can configure zero, one, or multiple dynamic interfaces on a distribution system port. However, all dynamic interfaces must be on a different VLAN or IP subnet from all other interfaces configured on the port. If the port is untagged, all dynamic interfaces must be on a different IP subnet from any other interface configured on the port.

Note A controller’s WLAN dynamic interface and all wireless clients in the WLAN that are local to the controller must have IP addresses in the same subnet.

Sandeep Choudhary
VIP Mentor

HI Gunter,

There are only 2 option:

1. Change the subnet mask to /23 to extends it.

2. Create a seperate dynamic interface in different vlan and then add old and new interface to Interface group.

then assign this interface group to your guest wlan.



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