Dell Force10 S4820T FTOS Command Reference Guide - Page 1519

57 Virtual Link Trunking (VLT) Overview Virtual Link Trunking (VLT) is supported on the and platforms. Virtual link trunking (VLT) allows physical links between two chassis to appear as a single virtual link to the network core or other switches such as Edge, Access or ToR. VLT reduces the role of Spanning Tree protocols by allowing LAG terminations on two separate distribution or core switches, and by supporting a loop free topology. (A Spanning Tree protocol is still needed to prevent the initial loop that may occur prior to VLT being established. After VLT is established, RTSP may be used to prevent loops from forming with new links that are incorrectly connected and outside the VLT domain.) VLT provides Layer 2 multipathing, creating redundancy through increased bandwidth, enabling multiple parallel paths between nodes and load-balancing traffic where alternative paths exist. Prerequisites: Before you configure VLT, make sure that both VLT peer switches are running the same FTOS version and are configured for RSTP as described in the Virtual Link Trunking (VLT) chapter in the FTOS Configuration Guide. Caution: Dell Force10 recommends not enabling Stacking and VLT simultaneously. If both are enabled at the same time, unexpected behavior will occur. Commands • back-up • back-up destination • clear vlt statistics • delay-restore • lacp ungroup member-independent • peer-link • peer-link port-channel • primary-priority • show vlt • show vlt backup-link Virtual Link Trunking (VLT) | 1519