> # E Port

> In expansion port (E port) mode, an interface functions as a fabric expansion port. This port may be connected to another E port to create an Inter-Switch Link (ISL) between two switches. E ports carry frames between switches for configuration and fabric management. They serve as a conduit between switches for frames destined to remote N ports and NL ports. E ports support class 2, class 3, and class F service.

> An E port connected to another switch may also be configured to form a PortChannel (see "Configuring PortChannels").

> Note We recommend that you configure E ports on 16-port modules. If you must configure an E port on a 32-port oversubscribed module, then you can only use the first port in a group of four ports (for example, ports 1 through 4, 5 through 8, and so forth). The other three ports cannot be used.

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