Editing Wake-on-LAN (section)

===Magic packet===
The ''magic packet'' is a [[Ethernet frame|frame]] that is most often sent as a [[Broadcasting (networking)|broadcast]] and that contains anywhere within its payload 6 [[bytes]] of all 255 (FF FF FF FF FF FF in [[hexadecimal]]), followed by sixteen repetitions of the target computer's 48-bit MAC address, for a total of 102 bytes.

Since the magic packet is only scanned for the string above, and not actually parsed by a full protocol stack, it could be sent as payload of any network- and transport-layer protocol, although it is typically sent as a [[User Datagram Protocol|UDP]] [[datagram]] to [[TCP and UDP port|port]] 0 (reserved port number),<ref>{{cite web |url=https://forums.ivanti.com/s/article/Understanding-Wake-On-LAN |title=Understanding Wake On LAN |work=LANdesk.com |access-date=28 October 2015}}</ref> 7 ([[Echo Protocol]]) or 9 ([[Discard Protocol]]),<ref>{{cite web|url=https://docs.microsoft.com/en-us/mem/configmgr/core/clients/deploy/plan/plan-wake-up-clients|title=Plan how to wake up clients in Configuration Manager|date=2019-04-23|website=[[Microsoft Docs]]|access-date=2020-10-29|quote=...&nbsp;By default, traditional wake-up packets are transmitted by using UDP port 9...}}</ref> or directly over Ethernet using [[EtherType]] 0x0842.<ref>{{cite web |url=http://wiki.wireshark.org/WakeOnLAN |title=WakeOnLAN |website=Wireshark wiki |access-date=2023-09-27}}</ref> A [[connection-oriented]] transport-layer protocol like [[Transmission Control Protocol|TCP]] is less suited for this task as it requires establishing an active connection before sending user data.

A standard magic packet has the following basic limitations:
* Requires destination computer MAC address (also may require a ''SecureOn'' password)
* Does not provide a delivery confirmation
* May not work outside of the [[local area network]]
* Requires hardware support for Wake-on-LAN in the destination computer
* Most 802.11 wireless interfaces do not maintain a link in low-power states and cannot receive a magic packet

The Wake-on-LAN implementation is designed to be simple and to be quickly processed by the circuitry present on the network interface controller using minimal power. Because Wake-on-LAN operates below the IP protocol layer, IP addresses and DNS names are meaningless and so the MAC address is required.