Datacenter Design IV ( VPC , MEC, Fabric Extenders )

What is a vPC (virtual Port Channel)

• Nexus series Network Virtualisation Technology.
• “Lightweight” VSS – Combine ports, not switches.
• Links on different switches to appear as the same device.
• Downstream device can be anything supoprting 802.3ad (LACP).
• Commonly called Multi Chassis Etherchannel ( MEC ).

Multi Chassis Etherchannel

• https://en.wikipedia.org/wiki/MC-LAG
• Multi chassis etherchannel ( MEC / MC-LAG ) allows two switches to appear as a single switch.
• Technology used to form a virtual switch ( VSS / vPC ) are not standard.
• MEC Provides load balancing and High Availability ( HA ).
• 16-port Etherchannel possibilities.

Fabric Extenders

• FEX: Top of Rack ( TOR ) concept with end of rack ( EOR ) benefits.
• Nexus 2000 series , seperate yet controlled from the parent switch.
• vPC on EOR switches feeds redundant FEXS for MEC capabilities.
• no STP, no L3 convergence – HA Ability of MEC.
• Aggregation switch is the brain, no local switching.