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Cisco Wireless LAN Controller Configuration Guide
OL-8335-02
Chapter 3 Configuring Ports and Interfaces
Overview of Ports and Interfaces
unused gateway IP address, such as 1.1.1.1. The virtual interface IP address is not pingable and should
not exist in any routing table in your network. In addition, the virtual interface cannot be mapped to a
backup port.
Note All controllers within a mobility group must be configured with the same virtual interface IP address.
Otherwise, inter-controller roaming may appear to work, but the hand-off does not complete, and the
client loses connectivity for a period of time.
Service-Port InterfaceThe service-port interface controls communications through and is statically mapped by the system to
the service port. It must have an IP address on a different subnet from the management, AP-manager,
and any dynamic interfaces, and it cannot be mapped to a backup port. This configuration enables you
to manage the controller directly or through a dedicated operating system network, such as 10.1.2.x,
which can ensure service access during network downtime.
The service port can obtain an IP address using DHCP, or it can be assigned a static IP address, but a
default gateway cannot be assigned to the service-port interface. Static routes can be defined through the
controller for remote network access to the service port.
Note Only Cisco 4100 and 4400 series controllers have a service-port interface.
Note You must configure an IP address on the service-port interface of both Cisco WiSM controllers.
Otherwise, the neighbor switch is unable to check the status of each controller.
Dynamic InterfaceDynamic 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 VLAN 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 Tagged VLANs must be used for dynamic interfaces.