Wake On LAN

Wake On LAN (WoL) networking standard enables remotely powering-up a shutdown computer from a sleeping state. In this process, the computer is shutdown with power reserved for the network card. A packet known as Magic Packet is broadcast on the local LAN or subnet. The network card on, receiving the Magic Packet, verifies the information. If the information is valid, the network card powers-up the shutdown computer.

The WoL Magic Packet is a broadcast frame sent over a variety of connectionless protocols, such as UDP. The most commonly used connectionless protocol is UDP. The Magic Packet contains data that is a defined constant represented in hexadecimal as FF:FF:FF:FF:FF:FF, followed by 16 repetitions of the target computer MAC address and possibly by a four or six byte password.

If you implement enhanced network security using 802.1X, the transmission of Magic Packets to sleeping or unauthorized network devices is blocked. You can use an interface specific 802.1X feature known as traffic-control to address this requirement of supporting both WoL and 802.1X Authentication simultaneously. The default mode is in-out. This mode blocks both ingress and egress unauthenticated traffic on an 802.1X port. Configuring the traffic control mode to in enables the transmission of Magic Packets to sleeping or unauthenticated devices. This mode allows any network control traffic, such as a WoL Magic Packet, to be sent to a workstation irrespective of the authentication or sleep status.

Important

Important

If a PC client is assigned to a VLAN based on a previous RADIUS Assigned VLAN, when the client goes into sleep or hibernation mode it reverts to either the default port-based VLAN or Guest VLAN configured for that port. Therefore, the WoL Magic Packet must be sent to the default VLAN or Guest VLAN.