Layer 2

In this section:

  1. Link Aggregation Group
    Link aggregation allows you to bundle multiple physical Ethernet links to form a single logical trunk providing enhanced performance and redundancy. The aggregated trunk is referred to as a Link Aggregation Group (LAG). The LAG is viewed as a single logical link by connected devices, the Spanning Tree Protocol (STP), IEEE 802.1Q VLANs, and so on. When one physical link in the LAG fails, the other links stay up. A small drop in traffic is experienced when the link carrying the traffic fails. To configure links to form a LAG, the physical links must be of the same speed.
  2. VLAN
    A virtual LAN (VLAN) is used to partition a computer network at Layer 2 into a broadcast domain, which is uniquely identified by a VLAN ID. A VLAN helps to split a network that acts as a separate network, but is connected to a physical network. Using VLAN tagging, you can virtually group networks together even if they are not physically connected to the same network switch.
  3. Monitoring LLDP Neighbors
    Link Layer Discovery Protocol (LLDP) is a Layer 2 neighbor discovery protocol that allows devices to advertise device information to other devices on the network. LLDP enables a station attached to an IEEE 802 LAN or MAN to advertise its capabilities to, and to discover, other stations in the same IEEE 802 LAN segments. By default, the system capabilities are automatically advertised when LLDP is enabled on a global basis.