5
ARP negotiation. The bonding driver intercepts the ARP replies sent by the local device and
changes the source MAC address into a unique MAC address of a backup device in bonding,
allowing different peers to communicate with different MAC addresses. This mode is used
commonly.
Teaming (Windows)
This section uses the teaming solution for Windows Server 2012 R2 operating system as an
example.
Teaming has the following modes:
•
Static teaming
—A switch-dependent mode in which member NICs must connect to the same
physical switch. This mode requires the support of the switch.
•
Switch independent
—Member NICs can be connected to different switches in active/standby
mode. Load balancing aggregation can be realized only when the member NICs connect to the
same switch.
•
LACP
—You must enable LACP on the switch first. This mode integrates multiple NICs into one
logical link. Data is transmitted at the fastest speed in LACP mode.
Besides teaming configuration, you must configure the load balancing mode. Load balancing has the
following modes:
•
Address hash mode
—In this mode, when a packet arrives at the team, the device uses the
hash algorithm to calculate the packet sending physical NIC based on the destination address
information (MAC address, IP address, and port number). This mode cannot control traffic
direction. If a large amount of traffic goes to the same destination address, the traffic will be sent
by the same physical NIC.
•
Hyper-V port mode
—Used for the Hyper-V mode. Compared with the address hash mode,
this mode has higher traffic distribution efficiency. In this mode, data are transmitted by different
physical NICs bound to the vNIC and the binding is based on vNICs instead of VMs. As a best
practice, enable this mode when you use a Hyper-V external virtual switch.
•
Dynamic mode
—Introduced for Windows Server 2012 R2 and later. In this mode, data is
evenly distributed to all NICs to make full use of bandwidth resources. This mode is the most
optimal load balancing mode.
TCP offloading
TCP offloading is a TCP acceleration technology, which allocates the TCP/IP stack work to NICs and
complete the work through hardware. On a high speed Ethernet, for example, 10-GE Ethernet,
processing TCP/IP packet headers consumes great CPU resources. Using NIC hardware to process
the headers can ease the CPU burden.
