User Manual

Rev 4.70

Mellanox Technologies

PA addresses are determined by using virtualization table. Hyper-V host retrieves the received

packet, identifies recipient and forwards the original packet with the CA addresses to the desired

VM.

NVGRE can be implemented across an existing physical IP network without requiring changes

to physical network switch architecture. Since NVGRE tunnels terminate at each Hyper-V host,

the hosts handle all encapsulation and de-encapsulation of the network traffic. Firewalls that

block GRE tunnels between sites have to be configured to support forwarding GRE (IP Protocol

47) tunnel traffic.

Figure 4: NVGRE Packet Structure

8.8.1 Enabling/Disabling NVGRE Offloading

To leverage NVGRE to virtualize heavy network IO workloads, the Mellanox ConnectX®-3 Pro

network NIC provides hardware support for GRE off-load within the network NICs by default.

 To enable/disable NVGRE off-loading:

Step 1. Open the Device Manager.

Step 2. Go to the Network adapters.

Step 3. Right click 'Properties on Mellanox ConnectX®-3 Pro Ethernet Adapter card.

Step 4. Go to Advanced tab.

Step 5. Choose the ‘Encapsulate Task Offload’ option.

Step 6. Set one of the following values:

• Enable - GRE off-loading is Enabled by default

• Disabled - When disabled the Hyper-V host will still be able to transfer NVGRE traffic, but TCP and

inner IP checksums will be calculated by software that significant reduces performance.