Editing IEEE 802.1Q (section)

{{short description|IEEE networking standard supporting VLANs}}

'''IEEE 802.1Q''', often referred to as '''Dot1q''', is the [[computer network|networking]] standard that supports [[virtual local area network]]ing (VLANs) on an [[IEEE 802.3]] [[Ethernet]] network. The standard defines a system of '''VLAN tagging''' for [[Ethernet frame]]s and the accompanying procedures to be used by [[Network bridge|bridges]] and [[Network switch|switches]] in handling such frames. The standard also contains provisions for a [[quality-of-service]] prioritization scheme commonly known as [[IEEE 802.1p]] and defines the [[Generic Attribute Registration Protocol]].

Portions of the network which are VLAN-aware (i.e., IEEE 802.1Q conformant) can include VLAN tags.  When a frame enters the VLAN-aware portion of the network, a tag is added to represent the VLAN membership.{{efn|VLAN membership is determined by the frame's port or the port/protocol combination, depending on whether port-based or port-and-protocol-based VLAN classification is being used.}}  Each frame must be distinguishable as being within exactly one VLAN.  A frame in the VLAN-aware portion of the network that does not contain a VLAN tag is assumed to be flowing on the '''native VLAN'''.

The standard was developed by [[IEEE 802.1]], a [[working group]] of the [[IEEE 802]] standards committee, and continues to be actively revised with notable amendments including [[IEEE 802.1ad]], [[IEEE 802.1ak]] and [[IEEE 802.1s]]. The 802.1Q-2014 revision incorporated the [[IEEE 802.1D-2004]] standard.<ref>[http://www.ieee802.org/1/pages/802.1Q-2014.html 802.1Q-2014 - Bridges and Bridged Networks]</ref>