Cisco Systems DSC9148D8G48PK9 manual Load Balancing, PortChanneling and Trunking

Chapter 6 Configuring PortChannels

Information About PortChannels

Figure 6-3 PortChanneling and Trunking

Switch 1		Switch 2	Switch 1
	ISL 1			EISL 1
	ISL 2			EISL 2
	ISL 3			EISL 3
Port	channel		Port	channel
			and trunking

Switch 2

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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 6-4illustrates 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.

	Cisco MDS 9000 Family NX-OS Interfaces Configuration Guide
6-4	OL-29284-01, Release 6.x