Teaming concepts – Dell Broadcom NetXtreme Family of Adapters User Manual
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Broadcom Gigabit Ethernet Teaming Services: Broadcom NetXtreme BCM57XX User Guide
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IP
Internet Protocol
LACP
Link Aggregation Control Protocol
Link Aggregation
(802.3ad)
Switch-dependent load balancing and failover type of team with LACP in which the intermediate driver
manages outgoing traffic and the switch manages incoming traffic.
LOM
LAN on Motherboard
MAC
media access control
NDIS
Network Driver Interface Specification
NLB
Network Load Balancing (Microsoft)
PXE
Preboot Execution Environment
RAID
Redundant array of inexpensive disks
Smart Load Balance
and Failover
Switch-independent failover type of team in which the primary team member handles all incoming and
outgoing traffic while the standby team member is idle until a failover event (for example, loss of link
occurs). The intermediate driver (BASP) manages incoming/outgoing traffic.
Smart Load
Balancing (SLB)
Switch-independent load balancing and failover type of team, in which the intermediate driver
manages outgoing/incoming traffic.
TCP
Transmission Control Protocol
UDP
User Datagram Protocol
WINS
Windows name service
WLBS
Windows Load Balancing Service
Teaming Concepts
The concept of grouping multiple physical devices to provide fault tolerance and load balancing is not new. It has been around
for years. Storage devices use RAID technology to group individual hard drives. Switch ports can be grouped together using
technologies such as Cisco Gigabit EtherChannel, IEEE 802.3ad Link Aggregation, Bay Network Multilink Trunking, and
Extreme Network Load Sharing. Network interfaces on Dell servers can be grouped together into a team of physical ports
called a virtual adapter.
Network Addressing
To understand how teaming works, it is important to understand how node communications work in an Ethernet network. This
document is based on the assumption that the reader is familiar with the basics of IP and Ethernet network communications.
The following information provides a high-level overview of the concepts of network addressing used in an Ethernet network.
Every Ethernet network interface in a host platform, such as a computer system, requires a globally unique Layer 2 address
and at least one globally unique Layer 3 address. Layer 2 is the Data Link Layer, and Layer 3 is the Network layer as defined
in the OSI model. The Layer 2 address is assigned to the hardware and is often referred to as the MAC address or physical
address. This address is pre-programmed at the factory and stored in NVRAM on a network interface card or on the system
motherboard for an embedded LAN interface. The Layer 3 addresses are referred to as the protocol or logical address
assigned to the software stack. IP and IPX are examples of Layer 3 protocols. In addition, Layer 4 (Transport Layer) uses port
numbers for each network upper level protocol such as Telnet or FTP. These port numbers are used to differentiate traffic
flows across applications. Layer 4 protocols such as TCP or UDP are most commonly used in today's networks. The
combination of the IP address and the TCP port number is called a socket.
Ethernet devices communicate with other Ethernet devices using the MAC address, not the IP address. However, most
applications work with a host name that is translated to an IP address by a Naming Service such as WINS and DNS.
Therefore, a method of identifying the MAC address assigned to the IP address is required. The Address Resolution Protocol
for an IP network provides this mechanism. For IPX, the MAC address is part of the network address and ARP is not required.
ARP is implemented using an ARP Request and ARP Reply frame. ARP Requests are typically sent to a broadcast address while
the ARP Reply is typically sent as unicast traffic. A unicast address corresponds to a single MAC address or a single IP
address. A broadcast address is sent to all devices on a network.
Teaming and Network Addresses