Figure 3.3 How traffic flows through the extensible switch and registered extensions
for the inbound path
Extensions to the switch are provided by the third parties, installed onto the Hyper-V
server, and then enabled per virtual switch. The process to enable an extension is
simple. Open the Virtual Switch Manager, select the virtual switch for which you want
to enable extensions, and then select the Extensions child node of the virtual switch.
In the extensions area of the dialog box, select the check box for the extension(s) you
wish to enable. That’s it! The extensions are now enabled. In Figure 3.4, you can see
the various extension types. Two are not part of standard Hyper-V: Microsoft VMM
DHCPv4 Server Switch Extension and sFlow Traffic Monitoring. When enabled, the
sFlow Traffic Monitoring extension sends trending information and more to the
sFlowTrend tool for graphical visualization and analysis. The Microsoft VMM DHCPv4
Server Switch Extension is a filter that, when it sees DHCP traffic, intercepts the
requests and utilizes IP pools within Virtual Machine Manager to service DHCP
requests over the virtual switch instead of using standard DHCP services, enabling
VMM to manage all IP configuration.