Dell Force10 Z9000 FTOS Configuration Guide for Z9000 System - Page 916

www.dell.com | support.dell.com Figure 48-1. Virtual Link Trunking S4810 Out-of-Band Management Network Backup Link VLT Domain Backup Link S4810 Chassis Chassis Interconnect Trunk Virtual Link Trunk Switch or Server that supports LACP (802.1ad) VLT peer devices have independent management planes. A chassis interconnect trunk between the VLT chassis maintains synchronization of L2/L3 control planes across the two VLT peers. The chassis interconnect trunk uses 10GE or 40GE user ports on the chassis. A separate backup link maintains heartbeat messages across an out-of-band management network. The backup link ensures that node failure conditions are correctly detected and are not confused with failures of the chassis interconnect trunk. VLT ensures that local traffic on a chassis does not traverse the chassis interconnect trunk and takes the shortest path to the destination via directly attached links. Virtual link trunking offers the following benefits: • Allows a single device to use a LAG across two upstream devices • Provides a loop-free topology • Uses all available uplink bandwidth • Provides fast convergence if either the link or a device fails • Optimized forwarding with VRRP • Provides link-level resiliency • Assures high availability 916 | Virtual Link Trunking (VLT)