Link Aggregation Control Protocol. LACP is part of the IEEE 802.3ad and automatically configures multiple aggregated links between switches.


Link aggregation group. A LAG is the logical high-bandwidth link that results from grouping multiple network links in link aggregation (or load sharing). You can configure static LAGs or dynamic LAGs (using the LACP).

Layer 2

Layer 2 is the second, or data link, layer of the OSI model, or the MAC layer. This layer is responsible for transmitting frames across the physical link by reading the hardware, or MAC, source and destination addresses.

Layer 3

Layer 3 is the third layer of the OSI model. Also known as the network layer, Layer 3 is responsible for routing packets to different LANs by reading the network address.


Light-emitting diode. LEDs are on the device and provide information on various states of the device‘s operation. See your hardware documentation for a complete explanation of the LEDs on devices running ExtremeXOS.

legacy certificate

The certificates that shipped with Extreme Management Center and NAC 4.0.0 and earlier.


Link Fault Signal. LFS, which conforms to IEEE standard 802.3ae-2002, monitors 10 Gbps ports and indicates either remote faults or local faults.


ExtremeXOS version 11.1 introduces a licensing feature to the ExtremeXOS software. You must have a license, which you obtain from Extreme Networks, to apply the full functionality of some features.

link aggregation

Link aggregation, also known as trunking or load sharing, conforms to IEEE 802.3ad. This feature is the grouping of multiple network links into one logical high-bandwidth link.

link type

In OSPF, there are four link types that you can configure: auto, broadcast, point-to-point, and passive.


Link Layer Discovery Protocol. LLDP conforms to IEEE 802.1ab and is a neighbor discovery protocol. Each LLDP-enabled device transmits information to its neighbors, including chassis and port identification, system name and description, VLAN names, and other selected networking information. The protocol also specifies timing intervals in order to ensure current information is being transmitted and received.

load sharing

Load sharing, also known as trunking or link aggregation, conforms to IEEE 802.3ad. This feature is the grouping of multiple network links into one logical high-bandwidth link. For example, by grouping four 100 Mbps of full-duplex bandwidth into one logical link, you can create up to 800 Mbps of bandwidth. Thus, you increase bandwidth and availability by using a group of ports to carry traffic in parallel between switches.

loop detection

In ELRP, loop detection is the process used to detect a loop in the network. The switch sending the ELRP PDU waits to receive its original PDU back. If the switch received this original PDU, there is a loop in the network.


Link state advertisement. An LSA is a broadcast packet used by link state protocols, such as OSPF. The LSA contains information about neighbors and path costs and is used by the receiving router to maintain a routing table.


Link state database. In OSPF, LSDB is a database of information about the link state of the network. Two neighboring routers consider themselves to be adjacent only if their LSDBs are synchronized. All routing information is exchanged only between adjacent routers.