Distributed switches explained
A distributed switch functions as a single virtual switch accross all associated ESXi hosts and allows virtual machines to maintain consistent network configuration as they migrate across multiple hosts. Just like standard switches, distributed switches forward frames at layer 2, support VLANs, NIC teaming, outbound traffic shaping, etc. The biggest difference between these two types of virtual switches is that distributed switches are configured using a central unified management interface through vCenter Server, which greatly simplifies virtual machine network configuration and reduces complexity in clustered ESXi environments. Distributed switches also support some advanced networking features that standard switches don’t, such as network I/O Control, port mirroring, network health check, and support for protocols such as NetFlow, Private VLAN (PVLAN), Link Aggregation Control Protocol (LACP), Link Layer Discovery Protocol (LLDP), etc.
In vCenter Server 5.5, five versions of distributed switches are available:
- Distributed Switch 5.5.0 – compatible with vSphere 5.5 and newer. Supports Traffic Filtering and Marking.
- Distributed Switch 5.1.0 – compatible with vSphere 5.1 and newer. Supports Management Network Rollback and Recovery, Health Check, Enhanced Port Mirroring, and LACP.
- Distributed Switch 5.0.0 – compatible with vSphere 5.0 and newer. Supports user-defined network resource pools in Network I/O Control, NetFlow, and Port Mirroring.
- Distributed Switch 4.1.0 – compatible with vSphere 4.1 and newer. Supports load-based teaming and Network I/O Control.
- Distributed Switch 4.0 – compatible with vSphere 4.0 and newer. Doesn’t support many of the features supported by later versions of distributed switches.