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Cisco MDS 9000 Family NX-OS Interfaces Configuration Guide
OL-29284-01, Release 6.x
Chapter 6 Configuring PortChannels
Information About PortChannels
Figure 6-3 PortChanneling and Trunking
PortChanneling and trunking are used separately across an ISL.
• PortChanneling—Interfaces can be channeled between the following sets of ports:
–
E ports and TE ports
–
F ports and NP ports
–
TF ports and TNP ports
• Trunking—Trunking permits carrying traffic on multiple VSANs between switches.
See the Cisco MDS 9000 Family NX-OS Fabric Configuration Guide.
• Both PortChanneling and trunking can be used between TE ports over EISLs.
Load Balancing
Two methods 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 6-4 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
Port channel
and trunking
Switch 1 Switch 2
ISL 3
ISL 2
ISL 1
Switch 1 Switch 2
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Port channel
