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The HMC-to-CPC communication is now possible through only an Ethernet switch that is connected to the J03 or J04 port on the SEs. Other IBM Z systems and HMCs also can be connected to the switch. To provide redundancy, install two Ethernet switches. 

Only the switch (and not the HMC directly) can be connected to the SEs. 

The connectivity between HMCs and the SEs is shown in Figure 11-8. 

<img src='content_image/987919.jpg'>

Various methods are available for setting up the network. It is your responsibility to plan and design the HMC and SE connectivity. Select the method that is based on your connectivity and security requirements. 

Security:  The configuration of network components, such as routers or firewall rules, is beyond the scope of this book. Whenever the networks are interconnected, security exposures can exist. For more information about HMC security, see Integrating the Hardware Management Console‘s Broadband Remote Support Facility into your Enterprise , SC28-6951. 

For more information about the HMC settings that are related to access and security, see the HMC and SE console help function or IBM Knowledge Center. 

