LANsegment
LAN segment is a portion of a local area network that is treated as a single data-link layer segment for forwarding decisions. In traditional Ethernet networks that use a shared medium such as coax or hubs, a LAN segment corresponds to the physical section of cable on which devices contend for access and thus forms a single collision domain. When two devices transmit simultaneously on such a segment, a collision may occur, and protocols like CSMA/CD coordinate retransmission.
In modern switched Ethernet, switches break up collision domains. Each switch port generally represents a separate
Routers separate broadcast domains, while switches do not by default. VLANs enable administrators to partition a
See also: LAN, Ethernet, collision domain, broadcast domain, VLAN.