Qlogic 8400 Series, User Manual

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17–QLogic Teaming Services
Teaming Mechanisms
293 83840-546-00 D
Dynamic Trunking (IEEE 802.3ad Link Aggregation)
This mode supports link aggregation through static and dynamic configuration
through the Link Aggregation Control Protocol (LACP). With this mode, all
adapters in the team are configured to receive packets for the same MAC
address. The MAC address of the first adapter in the team is used and cannot be
substituted for a different MAC address. The ASP driver determines the
load-balancing scheme for outbound packets, using Layer 4 protocols previously
discussed, whereas the team’s link partner determines the load-balancing
scheme for inbound packets. Because the load balancing is implemented on
Layer 2, all higher protocols such as IP, IPX, and NetBEUI are supported. The
attached switch must support the 802.3ad Link Aggregation standard for this
mode of operation. The switch manages the inbound traffic to the adapter while
the ASP manages the outbound traffic. Both the ASP and the switch continually
monitor their ports for link loss. In the event of link loss on any port, traffic is
automatically diverted to other ports in the team.
Network Communications
The following are the key attributes of Dynamic Trunking:

Failover mechanism – Link loss detection

Load Balancing Algorithm – Outbound traffic is balanced through a QLogic
proprietary mechanism based on L4 flows. Inbound traffic is balanced
according to a switch specific mechanism.

Outbound Load Balancing using MAC Address - No

Outbound Load Balancing using IP Address - Yes

Multivendor teaming – Supported (Must include at least one QLogic
Ethernet adapter as a team member)
Applications
Dynamic trunking works with switches that support IEEE 802.3ad Link
Aggregation dynamic mode using LACP. Inbound load balancing is switch
dependent. In general, the switch traffic is load balanced based on L2 addresses.
In this case, all network protocols such as IP, IPX, and NetBEUI are load
balanced. Therefore, this is the recommended teaming mode when the switch
supports LACP, except when switch fault tolerance is required. SLB is the only
teaming mode that supports switch fault tolerance.
Configuration Recommendations
Dynamic trunking supports connecting the teamed ports to switches as long as
they are on the same broadcast domain and supports IEEE 802.3ad LACP
trunking. It does not support connecting to a router or Layer 3 switches since the
ports must be on the same subnet.