Main-Interface that is bound to the physical interfaces. For the WLC 5520, the “management” interface lies on the installed 10 Gbit Ports “Port 1” and “Port 2”. When you activate the LAG function, all physical ports (except the yellow copper ports) will be bound to one LAG. Enabling or disabling the LAG option is only possible while your WLC is not configured with “Redundancy SSO” / High Availability. In an HA-Environment, the configured IP address is a virtual IP address which are shared by both WLCs. If the primary WLC fails, the secondary WLC is taking over the management IP. The management IP is the target for all your access points.
Beside the Redundancy-Port, another Interface for Heartbeats. This interface delivers a SSH access. Every HA-Node / WLC has its own IP address. For example, in a case of a broken HA situation, you can access the standby-controller directly to make debugs, troubleshooting and rebooting the system (it’s the “reset system” command ^^). This interface automatically configures the same VLAN tag as the “management” interface.
Serial line / COM port (IOIOI)
This is the serial port of the WLC. Access is possible via 9600 Baud. Initial-configuration is done at this interface. If a WLC has no configuration (factory default) an automatic-install process starts after 60 seconds. You can abort this by answering the question with “n” or “no”.
The service port is an additional port for accessing the devices via SSH or webinterface. If the device is configured for High Availability, the service port only accept SSH login. There is no possibility to configure a VLAN tag or a gateway, so you need to come from the same net or connecting from a different network via source natting. The IP address must be different to the “management”-interface.
The redundancy-port is for configuration-sync and for the keep-alive UDP packets (heartbeat). The default-timer for heartbeats is 100 milliseconds. The IP address will be automatically configured by activating “Redundancy SSO” / High Availability. The first two octets of the IP address will configured to 169.254 and the last ones will be assumed from the “redundancy-management” interface. The physical ports can be connected directly via copper or transported via VLANs. The RP has no VLAN tag configuration so the directly connected switch-port needs to be an access-port with the untagged VLAN.