Rapid Spanning Tree Protocol (Rstp) - Vertiv Geist GU2 Series Installer/User Manual

Table 3.3 IMD-3E-S Module Descriptions
NUMBER NAME
Dual
1 Ethernet
Ports
Hard-
2 Reboot
Button
Network
3 Reset
Button
Local
4
Display
Display
5
Buttons
Remote
6 Sensor
Port
Serial
7
Port
USB
8
Port
NOTE: GU2 PDUs support the use of USB MSC devices such as thumb drives or external hard drives.
USB Storage Devices must be formatted as FAT32.

3.1.3 Rapid Spanning Tree Protocol (RSTP)

GU2 devices, include two Ethernet ports which work together as an internal Ethernet bridge. One of these
ports can be used to connect the IMD to an existing network, or both ports can be used at the same time
to connect one IMD to another in a daisy-chain configuration.
When both network interfaces are connected, the IMD implements a network bridging protocol called the
Rapid Spanning Tree Protocol (RSTP). RSTP is an IEEE standard that is implemented by all managed
bridges. Using RSTP, bridges in the network exchange information to find redundant paths, or loops.
When a loop is detected, the bridges in the network work together to temporarily disable the redundant
paths. This allows the network to avoid broadcast storms caused by the loops. In addition, RSTP regularly
checks for changes in the network topology. When a connection is lost, RSTP allows the bridges to quickly
switch to a redundant path.
NOTE: RSTP protocol imposes a limit of 40 links between bridges, including IMDs.
20
DESCRIPTION
The Dual Ethernet ports act as a 2-port Ethernet switch, allowing for multiple de- vices to be daisy- chained.
Pressing the hard-reboot button reboots the IMD. This acts as a power-cycle for the IMD, and does not
change or remove any user information.
Holding the network-reset button for 5 seconds during normal operation will restore the default IP address
and reset the user accounts. Holding the network-reset button during power-up will reset all of the unit's
settings back to factory-default values.
The local display shows the phase, line, and circuit current values (in Amperes).
There are three buttons near the IMD display; a back button, a forward button, and a center button. The
functions of these buttons are described in the Display buttons table.
RJ-12 port for connecting a Vertiv plug-and-play remote digital sensors (sold separately). Each digital sensor
has a unique serial number and is automatically discovered. GU2 PDUs support up to 16 sensors. The optional
Vertiv A2D Converter can be added to support analog sensing. For more information see,
on page 72.
RS-232 via RJ-45 port.
USB Port used to upload firmware, backup/restore device configuration, or expanded logging capacity via
USB storage device. Provides up to 500mA power capacity for USB connected devices.
Available Sensors
Vertiv | Intelligent Rack PDU Installer/User Guide