About Load Balancing - HP Cisco MDS 9216 - Fabric Switch Configuration Manual

About PortChannels
S e n d d o c u m e n t a t i o n c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m
Figure 23-3
Switch 1
Port Channeling
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Both PortChanneling and trunking can be used between TE ports over EISLs.

About Load Balancing

Two mechanisms support the load balancing functionality:
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Figure 23-4
When the first frame in a flow is received on an interface for forwarding, link 1 is selected. Each
subsequent frame in that flow is sent over the same link. No frame in SID1 and DID1 utilizes link 2.
Cisco MDS 9000 Family CLI Configuration Guide
23-4
PortChanneling and Trunking
Switch 2
ISL 1
ISL 2
ISL 3
PortChanneling—Interfaces can be channeled between E ports and TE ports.
Trunking—Interfaces can be trunked only between TE ports. Trunking permits carrying traffic on
multiple VSANs between switches.
See Chapter 26, "Configuring and Managing VSANs."
Flow based—All frames between source and destination follow the same links for a given flow. That
is, whichever link is selected for the first exchange of the flow is used for all subsequent exchanges.
Exchange based—The first frame in an exchange picks a link and subsequent frames in the exchange
follow the same link. However, subsequent exchanges can use a different link. This provides more
granular load balancing while preserving the order of frames for each exchange.
illustrates how source ID 1 (SID1) and destination ID1 (DID1) based load balancing works.
Switch 1
EISL 1
EISL 2
EISL 3
PortChanneling
and trunking
OL-16184-01, Cisco MDS SAN-OS Release 3.x
Chapter 23 Configuring PortChannels
Switch 2