As we get into software defined networking the lines will blur more and more but at this point normal virtual switches have not changed much over the years.
What does a vSwitch do?
- Layer 2
- has MAC address tables
- forwards ethernet frames
- supports VLAN configurations
- able to trunk based on 802.1q VLAN tags
- can establish port channels
- Cannot support the following on layer 2
- Dynamic negotiation protocols (like DTP or PAgP)
- Cannot be connected to another vSwitch (making loops impossible and removing the need for STP)
- vSwitches are unique in that
- They authoritatively know the MAC addresses of all connected VM’s no need for learning
- Does not need to perform IGMP snooping because it knows the multicast of attached vm’s