Users Guide

Table Of Contents
Virtual Link Trunking
Virtual Link Trunking (VLT) is a Layer 2 aggregation protocol used between an end device such as a server and two or more connected
network devices. VLT helps to aggregate ports terminating on multiple switches. OS10 currently supports VLT port channel terminations on
two dierent switches.
VLT:
Provides node-level redundancy by using the same port channel terminating on multiple upstream nodes.
Provides a loop-free topology
Eliminates STP-blocked ports
Optimizes bandwidth utilization by using all available uplink bandwidth
Guarantees fast convergence if either a link or device fails
Enhances optimized forwarding with Virtual Router Redundancy Protocol (VRRP)
Optimizes routing with VLT peer routing for Layer-3 VLANs
Provides link-level resiliency
Assures high availability
VLT presents a single logical L2 domain from the perspective of attached devices that have a virtual link trunk terminating on separate
nodes in the VLT domain. The two VLT nodes are independent Layer2/ Layer3 (L2/L3) switches for devices in the upstream network.
L2/L3 control plane protocols and system management features function normally in both the VLT nodes.
External switches or servers supporting LACP see the two VLT switches as a single virtual switch. Hence, VLT congurations must be
identical on both the switches in the VLT domain.
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