F10-VIRTUAL-LINK-TRUNK-MIB

This MIB module provides information on Dual Brain Virtual Link Trunk(VLT) feature which is a control plane mechanism to provide Layer2 multipathing between access network devices (switches or servers) and the core network. VLT represents a single logical layer 2 domain from the view of downstream devices that have LAG bundles terminating on separate chassis in the virtual link trunk domain. However, the two VLT chassis are independent L2/L3 switches for devices in the upstream network. A sample of VLT scenario: --------------------------------------------------------------- | _______________ | | | Edge router | | | |_______________| | | / \ | | / \ | | VLT / \ | | ____________/_______________________\____________ . | | | _______/ Back Up Link \_______ | /|\| | | | |-------------------------| | | | | | | | | ------- | | | L3| | | | | S4810 |________| Inter |________| S4810 | |_____| | | | |________|Chassis|________| | | L2| | | | | | | Link | | | | | | | VLT port \_____\ ------- /____/VLT port\|/| | |_____\_____\_________________________/____/_____| . | | \ \ -----------------/ / | | \ \----/------------ / | | \ / \ / | | \ / \ / | |Lag(active)<--- \ / \ /--->Lag(active) | | ___\__/___________________\_/______ | | | _______ Stacking ______ | | | | | S60 |--------------| S60 | | | | | |__\____| |____/_| | | | |_____\______________________/______| | | \ /-->Nic teaming | | \__________________/ | | | Nic1 Nic2 | | | | Server | | | |____________________| | --------------------------------------------------------------- Benefits of VLT are as follows: > Allows a single device to use LAG across two upstream devices > Eliminates Spanning Tree Protocol (STP) blocked ports > Provides a loop-free topology > Uses all available uplink bandwidth > Provides fast convergence if either the link or a device fails > Provides link-level resiliency > Assures high availability GLOSSARY AND ABBREVIATIONS VLT - Virtual Link Trunk The combined port channel between the VLT peer devices and the downstream device. VLT Peer device One of a pair of devices that are connected with the special port channel known as the chassis interconnect trunk. VLT Chassis Interconnect Trunk The link used to synchronize states between the VLT peer devices. VLT domain This domain includes both VLT peer devices, the VLT chassis interconnect trunk, and all of the port channels in the VLT connected to the downstream devices. VLT Backup link The backup link monitors the vitality of a VLT peer device. The backup trunk sends configurable, periodic heart beat messages between VLT peer devices. ICL Abbreviation for Chassis InterConnect Link.