Administrator Guide

ECP Tx: 10
ECP Rx Ack: 10
ECP Dropped: 0
ECP Rx: 6
ECP Tx Ack: 6
Dell#show pe 10 system brief
Stack MAC : a0:68:00:3f:92:bc
-- Stack Info --
Unit UnitType Status ReqTyp CurTyp Version Ports
------------------------------------------------------------------------------------
0 Management online C1048P C1048P 9-9(0-5) 52
1 Member not present
2 Standby not present C1048P
3 Member not present C1048P
4 Member not present
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 configuration, 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 traffic sent towards PE interfaces causing continuous MAC movements
between PE interfaces. Based on the threshold and interval configured, the PE interface with lowest ifindex 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 traffic too. The interface learnt first 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 traffic, 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 specified MAC address exceeds the configured threshold value in the configured time, a loop is
detected on the PE ports.
To specify the threshold value and timer interval for the maximum number of station move:
Port Extenders (PEs)
671