Geist Upgradeable PDU - Manual (Page 17)

Interchangeable Monitoring Device 17
© 2015 Geist GM1157 - GU PDU Instruction Manual
Back Button Decrement to the previous channel.
Forward Button Increment to the next channel.
Center Button Toggle between scrolling and static display modes.
Holding this button for 10 seconds will perform a network
reset, restoring the default IP address and resetting user
account information
and
Flip the display 180 degrees. (Both buttons must be
pressed at the same time.)
and
Display the unit's primary IPv4 address. (Both buttons
must be pressed at the same time.)
3.3 Rapid Spanning Tree Protocol (RSTP)
Geist Upgradable monitored devices built with the IMD-02X include two Ethernet ports
which act 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.
Since every IMD-02X runs RSTP, a chain of only IMDs can be connected redundantly
to an external switch, even an unmanaged (dumb) switch. In this configuration, if a link
of the chain is disconnected, the IMDs will quickly switch to the alternate path and
connectivity will not be lost.
The only limitation is that the RSTP protocol imposes a limit of 40 links between
bridges, including IMDs.
3.4 Network Setup
The Monitored Geist Upgradeable PDU has a default IP address for initial setup and
access to the unit. Once you have assigned an IP address to a unit, the default IP