Port extender considerations

Keep the following points in mind when configuring PE units.

• All ICX 7150 models except the ICX 7150-C08P can be enabled as PE units.
• All ICX 7250 models except the ICX 7250-24L can be enabled as PE units.
• All ICX 7450 models, including ICX 7450-32ZP devices, can be enabled as PE units.
• In a Campus Fabric domain, no local switching occurs on the PE ports. All data and control packet processing occurs in the CB. No IP addressing is possible on the physical PE ports; however, virtual interfaces (VEs) are supported.
• Client-facing LAGs are not supported over PE virtual ports.
• Units in a stack must be disconnected, and stacking must be disabled before the units can be enabled as PEs. Likewise, if a standalone unit is enabled for stacking, stacking must be disabled before the unit can be enabled as a PE.
• Only standalone units running a router image can be enabled as PE units. Although PE units cannot run a switch image, if a TFTP server with the appropriate router image is connected to the Campus Fabric domain and a path to the image is provided, the CB will upgrade the PE image automatically. Refer to SPX image upgrade. The converted unit can retain a stacking configuration and can later be reloaded with a switch image, if necessary.
• PE units can join a Campus Fabric domain only after at least one working SPX port or SPX LAG has been configured on both the CB and PE. Once a PE is enabled and configured, you must issue the write memory and reload commands to complete initialization.
• Each PE unit can have no more than two SPX connections, one upstream connection toward the CB and one downstream connection to another PE unit. These connections can be two SPX links, two SPX LAGs, or one SPX link and one SPX LAG. Only one SPX connection is allowed between two PE units.
• No speed negotiation is possible over an SPX connection. The speed at both ends of an SPX connection must be the same.
  Note: To convert a 1-Gbps SPX link on ICX 7150 or ICX 7250 devices to a 10-Gbps SPX link, you must disable the SPX link or LAG and change speed at both ends before re-enabling the SPX link or LAG. For more information, refer to Converting ICX 7150 or ICX 7250 1-Gbps SPX links to 10 Gbps.
• Allowable PE IDs are from 17 through 56.

For information on supported and unsupported topologies, refer to Campus Fabric topology overview.

For information on PE unit and PE port scaling, refer to Campus Fabric scalability.