IBM L2/3 X, X

Chapter 7. Nortel Networks L2/3 GbESM configuration and network integration 63

Figure 7-1 What trunk failover can protect against

7.3.2 Introduction to NIC Teaming

NIC Teaming is a function that is provided by Broadcom, the manufacturer of the NIC chips

used on the Blade Servers, in their software. Broadcom provides the Broadcom Advanced

Services Protocol (BASP) which includes NIC teaming, as well as the Broadcom Advanced

Control Suite (BACS) which is a Windows application which helps configure NIC teaming.

NIC teaming allows two or more physical NICs to be treated as a single logical network object

in Windows or a single /dev/eth file in Linux. The single object or file can then be assigned

network properties such as an IP address in the same way as any other NIC.

The BACS application allows several types of teams to be created. For HA designs, the

Smart Load Balancing (SLB) team is used. Layer 2 designs can have both of the adapters (on

an HS20 blade) as active members of the team; for Layer 3 designs, an active or standby

team is used with one adapter as an active member of the team and the second adapter as a

standby member of the team.

NIC teaming is intended to provide both additional capacity (bandwidth) as well as High

Availability. The team will detect loss of signal on any of its member NICs and continue to

send traffic through other active members, or activate standby members if necessary. In the

IBM Eserver BladeCenter, NIC teaming will detect the failure of a NIC chip on the server

blade, the loss of connection to a switch module via the midplane, and the failure of a switch

module (including intentional removal or power-off). Of these, intentional removal or power-off

of a switch module is by far the most common.

The BASP drivers also provide support for 802.1q tagging of the server NIC. This allows

support for multiple VLANs on a single physical NIC or on a group of teamed NICs. When this

capability is used, each VLAN has its own network object (windows) or /dev/eth file (Linux).

Thus, each VLAN can be assigned its own IP address. This can be useful to isolate different

categories of traffic from each other or to provide different Quality of Service (QoS)

configurations for different types of traffic whose target is the same server. A sample

If failure anywhere on the link toward the

upstream switch, the NIC on Blade server

does not know about the failure and may

continue to send traffic toward the top switch,

which will discard the traffic. - The Trunk

Failover feature addresses this issue.

If the switch fails in such a way that the link

toward the Blade server goes down, or NIC

fails, Blade server can sense this and

redirect traffic out the other NIC toward the

bottom switch. NIC Teaming can take care of

this without the need for trunk failover.

1 2 3 4 5 6 1 2 3 4 5 6

GbESM

VLAN X

Teamed

Active/Standby

NIC1 NIC2

Logical NIC Interface

Blade server 1

BladeCenter

Topology 1 - Trunk Failover