Chapter 6 Configuring PortChannels

Information About PortChannels

Provides high availability on an ISL. If one link fails, traffic previously carried on this link is switched to the remaining links. If a link goes down in a PortChannel, the upper protocol is not aware of it. To the upper protocol, the link is still there, although the bandwidth is diminished. The routing tables are not affected by link failure. PortChannels may contain up to 16 physical links and may span multiple modules for added high availability.

Note See the Cisco MDS 9000 Family NX-OS Fabric Configuration Guide for information about failover scenarios for PortChannels and FSPF links.

F and TF PortChannels

An F PortChannel is also a logical interface that combines a set of F ports connected to the same Fibre Channel node and operates as one link between the F ports and the NP ports. The F PortChannels support bandwidth utilization and availability like the E PortChannels. F PortChannels are mainly used to connect MDS core and NPV switches to provide optimal bandwidth utilization and transparent failover between the uplinks of a VSAN.

An F PortChannel trunk combines the functionality and advantages of a TF port and an F PortChannel. This logical link uses the Cisco PTP and PCP protocols over Cisco EPP (ELS).

Note If a Cisco MDS 9124 or 9134 switch is used as a core switch, only a nontrunking F PortChannel is supported. Trunking is not supported on this platform when NPIV enabled.

PortChanneling and Trunking

Trunking is a commonly used storage industry term. However, the Cisco NX-OS software and switches in the Cisco MDS 9000 Family implement trunking and PortChanneling as follows:

PortChanneling enables several physical links to be combined into one aggregated logical link.

Trunking enables a link transmitting frames in the EISL format to carry (trunk) multiple VSAN traffic. For example, when trunking is operational on an E port, that E port becomes a TE port. A TE port is specific to switches in the Cisco MDS 9000 Family. An industry standard E port can link to other vendor switches and is referred to as a nontrunking interface (See Figure 6-2and Figure 6-3). See Chapter 5, “Configuring Trunking,” for information on trunked interfaces.

Figure 6-2

Trunking Only

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E port

 

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Cisco Systems DSC9148D8G48PK9 manual TF PortChannels, PortChanneling and Trunking, Trunking Only