After the HMC console completes all FTP operations, the HMC console performs the FTP operation on the SE’s behalf and returns the results. The IBM Z platform must be managed by at least one HMC to allow FTP operations to work. 

## Secure console-to-console communication 

Before z14, IBM Z HMC consoles used anonymous cipher suites to set console-to-console communication. Anonymous cipher suite is a part of SSL/TLS protocol and it can be used to create internal point-to-point connections. Anonymous cipher suite does not exchange certificates, which can be the source of a security breach. 

Therefore, z14 HMC consoles abandon anonymous cipher suite and implement an industry standard-based, password-driven cryptography system. The Domain Security Settings are used to provide authentication and high-quality encryption. Because of these changes, we now recommend that customers use unique Domain Security settings to provide maximum security. The new system provides greater security than anonymous cipher suites, even if the default settings are used. 

To allow greater flexibility in password selection, the password limit was increased to 64 characters and special characters are allowed for z14 only installations. If communication with older systems is needed, the previous password limits must be followed (6 - 8 characters, only uppercase and number characters allowed). 

For more information about HMC networks, see the following resources: 

GLYPH<SM590000> The HMC and SE (Version 2.14.0) console help system, or IBM Knowledge Center 

## 11.3.2 Hardware prerequisite changes 

GLYPH<SM590000> IBM 3907 Installation Manual for Physical Planning,  GC28-6974 

The following HMC changes are important for z14 ZR1: 

GLYPH<SM590000> IBM does not provide Ethernet switches with the system. 

GLYPH<SM590000> RSF is broadband-only. 

## Ethernet switches 

Ethernet switches for HMC and SE connectivity are provided by the customer. Existing supported switches can still be used. 

Ethernet switches and hubs often include the following characteristics: 

GLYPH<SM590000> A total of 16 auto-negotiation ports 

GLYPH<SM590000> 100/1000 Mbps data rate 

GLYPH<SM590000> Full or half duplex operation 

GLYPH<SM590000> Auto medium-dependent interface crossover (MDIX) on all ports 

GLYPH<SM590000> Port status LEDs 

Note:  The recommendation is to use 1000 Mbps/Full duplex. 

## RSF is broadband-only 

RSF through a modem is not  supported on the z14 ZR1 HMC. Broadband is needed for hardware problem reporting and service. For more information, see 11.4, “Remote Support Facility” on page 374. 

