Dell PowerConnect 55xx Systems User Guide 15• Security Features• DHCP Server• Protected Ports• iSCSI Optimization• Proprietary Protocol FilteringIP Version 6 (IPv6) SupportThe device functions as an IPv6-compliant host, as well as an IPv4 host (alsoknown as dual stack). This enables device operation in a pure IPv6 network aswell as in a combined IPv4/IPv6 network.For more information, see "IP Addressing" on page 202.Stack SupportThe system supports up to eight units with two fixed HDMI stacking ports.The HDMI ports are 1.3a specification, Category 2 High Speed cables, 340MHz (10.2 Gbit/s).it is recommended to use HDMI cable version 1.4The stacking feature supports the following features:• Fast-link failover• Software auto-synch.• Improved response time to events, such as master failover• Auto-numbering algorithm when choosing unit numberFor more information, see "Stacking Overview" on page 43Power over EthernetPower over Ethernet (PoE) provides power to devices over existing LANcabling, without updating or modifying the network infrastructure. WhenPoE is used, the network devices do not have to be placed next to a powersource. PoE can be used in the following applications:• IP Phones• Wireless Access Points
