Broadcom Teaming Services: Broadcom NetXtreme II Network Adapter User Guide
file:///T|/htdocs/NETWORK/BroadCom/71921/NetXtremeII/en/teamsvcs.htm[9/26/2012 3:29:14 PM]
TCP------> PhysAdapter2 ------> 10.0.0.1
UDP------> PhysAdatper3 ------> 10.0.0.1
The actual assignment between adapters may change over time, but any protocol that is not TCP/UDP based goes over the
same physical adapter because only the IP address is used in the hash.
Performance
Modern network interface cards provide many hardware features that reduce CPU utilization by offloading certain CPU
intensive operations (see
Teaming and Other Advanced Networking Properties
). In contrast, the BASP intermediate driver is a
purely software function that must examine every packet received from the protocol stacks and react to its contents before
sending it out through a particular physical interface. Though the BASP driver can process each outgoing packet in near
constant time, some applications that may already be CPU bound may suffer if operated over a teamed interface. Such an
application may be better suited to take advantage of the failover capabilities of the intermediate driver rather than the load
balancing features, or it may operate more efficiently over a single physical adapter that provides a particular hardware
feature such as Large Send Offload.
Types of Teams
Switch-Independent
The Broadcom Smart Load Balancing type of team allows two to eight physical adapters to operate as a single virtual adapter.
The greatest benefit of the SLB type of team is that it operates on any IEEE compliant switch and requires no special
configuration.
Smart Load Balancing and Failover
SLB provides for switch-independent, bidirectional, fault-tolerant teaming and load balancing. Switch independence implies
that there is no specific support for this function required in the switch, allowing SLB to be compatible with all switches. Under
SLB, all adapters in the team have separate MAC addresses. The load-balancing algorithm operates on Layer 3 addresses of
the source and destination nodes, which enables SLB to load balance both incoming and outgoing traffic.
The BASP intermediate driver continually monitors the physical ports in a team for link loss. In the event of link loss on any
port, traffic is automatically diverted to other ports in the team. The SLB teaming mode supports switch fault tolerance by
allowing teaming across different switches- provided the switches are on the same physical network or broadcast domain.
Network Communications
The following are the key attributes of SLB:
Failover mechanism – Link loss detection.
Load Balancing Algorithm – Inbound and outbound traffic are balanced through a Broadcom proprietary mechanism
based on L4 flows.
Outbound Load Balancing using MAC Address - No.
Outbound Load Balancing using IP Address - Yes
Multivendor Teaming – Supported (must include at least one Broadcom Ethernet adapter as a team member).
Applications
The SLB algorithm is most appropriate in home and small business environments where cost is a concern or with commodity
switching equipment. SLB teaming works with unmanaged Layer 2 switches and is a cost-effective way of getting redundancy
and link aggregation at the server. Smart Load Balancing also supports teaming physical adapters with differing link
capabilities. In addition, SLB is recommended when switch fault tolerance with teaming is required.
Configuration Recommendations
SLB supports connecting the teamed ports to hubs and switches if they are on the same broadcast domain. It does not
support connecting to a router or Layer 3 switches because the ports must be on the same subnet.
Switch-Dependent
Generic Static Trunking
