Administrator Guide

The following figure shows how the core/aggregation port density in the Layer 2 topology is increased using
mVLT. For inter-VLAN routing and other Layer 3 routing, a separate Layer 3 router is required.
Figure 121. Multi-Domain VLT Example
VLT Terminology
The following are key VLT terms.
• Virtual link trunk (VLT) — The combined port channel between an attached device and the VLT peer
switches.
• VLT backup link — The backup link monitors the vitality of VLT peer switches. The backup link sends
configurable, periodic keep alive messages between the VLT peer switches.
• VLT interconnect (VLTi) — The link used to synchronize states between the VLT peer switches. Both
ends must be on 10G or 40G interfaces.
• VLT domain — This domain includes both the VLT peer devices, VLT interconnect, and all of the port
channels in the VLT connected to the attached devices. It is also associated to the configuration mode
that you must use to assign VLT global parameters.
• VLT peer device — One of a pair of devices that are connected with the special port channel known as
the VLT interconnect (VLTi).
Virtual Link Trunking (VLT) 953