Concept Guide
5 Member not present
6 Member not present
7 Member not present
-- Power Supplies --
Unit Bay Status Type FanStatus FanSpeed(rpm)
-------------------------------------------------------------------------
0 0 up AC NA NA
0 1 absent NA NA
-- Fan Status --
Unit Bay TrayStatus Fan0 Speed Fan1 Speed
------------------------------------------------------------------------------------
0 0 up up 8888 up 9056
Speed in RPM
For more information about verifying the PE conguration, see Displaying PE Stack Information.
Resetting a Port Extender
To reload a PE, enter the reset command.
• reset pe pe-id stack-unit pe-stack-unit-id
EXEC Privilege
– pe-id is a port-extender ID number from 0 to 255.
– pe-stack-unit-id is a PE stack-unit ID number from 0 to 7.
Dell# reset pe 0 stack-unit 1
Preventing Loops on Port Extender Ports
The existing behavior of Loop detection module is a simple loop detection mechanism in L2 to detect loops between PE interfaces and
break the loop. This mechanism is purely based on the data trac sent towards PE interfaces causing continuous MAC movements
between PE interfaces. Based on the threshold and interval congured, the PE interface with lowest index is shut down, thereby breaking
the loop. As per the enhancement added from Dell Networking OS 9.11.2.0, the PE loop detection mechanism works based on the control
trac too. The interface learnt rst for a MAC address is considered as old interface and the interface learnt later for the same MAC is
considered as the new interface. In case of loop detection the new interface will be brought down by the PE loop detection module. Also,
based on control trac, the interface receiving self originated packets will be shut down by the loop detection module. You can specify the
threshold value and a time interval for the maximum number of station moves to prevent loops on a port extender (PE) port using the
mac-address-table station-move threshold number interval seconds command to bring down the line protocol on
all active ports in the learned path, except for the port with the lowest interface index (ifIndex), to prevent a possible loop. When the
number of station moves for a specied MAC address exceeds the congured threshold value in the congured time, a loop is detected on
the PE ports.
To specify the threshold value and timer interval for the maximum number of station move:
1 Enter Conguration mode.
CONFIGURATION mode
Dell(conf)# mac-address-table station-move threshold number interval seconds
• number is the threshold value. The range is from 5 to 50.
After you enter a threshold value, you can specify a time interval in seconds. The range is from 1 to 60 seconds.
Dell(conf)# mac-address-table station-move threshold 5 interval 30
Port Extenders (PEs)
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