Dell Broadcom NetXtreme Family of Adapters User Manual
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Broadcom Teaming Services: Broadcom NetXtreme II® Network Adapter User Guide
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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
A team of adapters function as a single virtual network interface and does not appear any different to other network devices
than a non-teamed adapter. A virtual network adapter advertises a single Layer 2 and one or more Layer 3 addresses. When
the teaming driver initializes, it selects one MAC address from one of the physical adapters that make up the team to be the
Team MAC address. This address is typically taken from the first adapter that gets initialized by the driver. When the system
hosting the team receives an ARP request, it selects one MAC address from among the physical adapters in the team to use
as the source MAC address in the ARP Reply. In Windows operating systems, the IPCONFIG /all command shows the IP and
MAC address of the virtual adapter and not the individual physical adapters. The protocol IP address is assigned to the virtual
network interface and not to the individual physical adapters.
For switch-independent teaming modes, all physical adapters that make up a virtual adapter must use the unique MAC
address assigned to them when transmitting data. That is, the frames that are sent by each of the physical adapters in the
team must use a unique MAC address to be IEEE compliant. It is important to note that ARP cache entries are not learned
from received frames, but only from ARP requests and ARP replies.
Description of Teaming Types
Smart Load Balancing and Failover
Link Aggregation (IEEE 802.3ad LACP)
There are three methods for classifying the supported teaming types:
One is based on whether the switch port configuration must also match the adapter teaming type.
The second is based on the functionality of the team, whether it supports load balancing and failover or just failover.
The third is based on whether the Link Aggregation Control Protocol is used or not.
shows a summary of the teaming types and their classification.
Table 2: Available Teaming Types
Teaming Type
Switch-Dependent
(Switch must support
specific type of team)
Link Aggregation Control
Protocol Support Required on
the Switch
Load
Balancing Failover
Smart Load Balancing and Failover (with
two to eight load balance team
members)
SLB (Auto-Fallback Disable)
Link Aggregation (802.3ad)
Generic Trunking (FEC/GEC)/802.3ad-
Draft Static