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Dell PowerConnect 55xx Systems User Guide
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Virtual Cable Testing (VCT)
VCT
detects and reports copper link cabling faults, such as open cables and
cable shorts.
For more information, see "Diagnostics" on page 255.
Auto-Negotiation
Auto-negotiation enables the device to advertise modes of operation. The
auto-negotiation function enables an exchange of information between two
devices that share a point-to-point link segment, and automatically
configures both devices to take maximum advantage of their transmission
capabilities.
The PowerConnect 5500 series enhances auto-negotiation by providing port
advertisement. Port advertisement enables the system administrator to
configure the port speeds that are advertised.
For more information, see "Port Configuration" on page 404 or "LAG
MDI/MDIX Support
Standard wiring for end stations is known as
Media-Dependent Interface
(MDI), and standard wiring for hubs and switches is known as
Media-
Dependent Interface with Crossover
(MDIX).
If auto-negotiation is enabled, the device automatically detects whether the
cable connected to an RJ-45 port is MDIX (crossed) or MDI (straight). This
enables both types to be used interchangeably.
If auto-negotiation is not enabled, only MDI (straight) cables can be used.
For more information, see "Port Configuration" on page 404 or "LAG
MAC Address Supported Features
MAC Address Capacity Support
The device supports up to 16K MAC addresses and it reserves specific MAC
addresses for system use.