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
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Cisco MDS 9000 Family CLI Configuration Guide
OL-16184-01, Cisco MDS SAN-OS Release 3.x
Chapter 16 Configuring PortChannels
About PortChannels
Figure 16-3
PortChanneling and Trunking
•
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 19, “Configuring and Managing VSANs.”
Both PortChanneling and trunking can be used between TE ports over EISLs.
About Load Balancing
Two mechanisms support the load balancing functionality:
•
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.
Figure 16-4
illustrates how source ID 1 (SID1) and destination ID1 (DID1) based load balancing works.
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.
EISL 3
EISL 2
EISL 1
PortChanneling
and trunking
Switch 1
Switch 2
ISL 3
ISL 2
ISL 1
Switch 1
Switch 2
79939
Port Channeling