WLC Interface
The Cisco Wireless Controller provides the necessary connectivity through an internal logical interface. These interfaces must be configured with an IP address, subnet mask, default gateway, and Dynamic Host Configuration Protocol (DHCP) server. Each interface is then assigned a physical port and VLAN ID.
WLC PORTS (Physical Interfaces):
Some ports may or may not be present, depending on the WLC model. All WLCs have a console port and a distribution system port.
1. Redundancy Port: This port is used for deployment architectures that support High Availability (HA) when two WLCs are available. In this configuration, the Redundant Port acts as a physical connection between the two WLCs via an Ethernet cable. Role negotiation between primary and secondary controllers is done through redundant ports that are also used to synchronize configuration and operational data. Redundancy Port checks peer availability by sending a UDP keepalive message from the standby hot WLC to the active WLC every 100ms days. Finally, the redundant port IP address is always 169.254.xxx.xxx, which is the first two bytes.
2. Service Port: In the event of a network failure, the service port is used for system recovery and maintenance and for out-of-band management of the controller. Note that service ports do not support VLAN trunking or VLAN tagging and should be connected to access ports on the switch. Additionally, this may prevent the administrator from accessing the controller’s management interface (more on this later), so it is not recommended to connect the service port to his VLAN, which is the same as the wired client’s network.
3. SFP/Ethernet Distribution System Ports: The WLC’s most important port is the distribution system port. This is to connect internal logical interfaces (explained later) and wireless client traffic to the rest of the network. High-end WLCs, such as his WLC 5500 series mentioned earlier, are equipped with multiple of his SFP-based distribution system ports that allow an engineer to connect his WLC to his network, his backbone in a variety of ways. By using the right SFP, you can connect your fiber optic or ethernet copper interface to its SFP port. Low-end WLCs such as the WLC2504 and the older WLC2100 series only offer Ethernet ports as only a few access points are supported. For example, the WLC2125 has up to 8 FastEthernet ports and supports up to 25 access points, while the WLC2504 offers up to 4 Gigabit Ethernet ports and can support up to 75 access points.
Physical Infrastructure Connections of WLAN Components
The IETF Control and Provisioning of Wireless Access Points Protocol (CAPWAP) standard are used by Lightweight Cisco Access Points for the purpose of communicating with wireless controllers and other lightweight access points on your network.