Users Guide

– 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
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 . 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. You can configure 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.
To specify the threshold value and timer interval for the maximum number of station move
1. Enter Configuration 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
NOTE: Dell Networking OS recommends that you use the command because xSTP protocols
are not supported on PEs.
2. If a station move for a MAC address is detected above the configured threshold and within the
specified time, a syslog message is triggered with the port information. All ports on which the station
move was detected are shut down, except for the port with the lowest interface index. Only the port
with the lowest ifIndex remains active. For example:
Jun 18 09:55:35: %RPM0-P:RP %MACMGR-1-PE LOOP DETECTION: Loop occurred on
PE interfaces:oldInterface: peGigE 0/2/47, newInterface: peGigE
0/1/20,vlanId: 3902, macAddr: 00:aa:00:00:00:
3. When a PE interface is shut down due to a PE loop violation, you must manually reset it. To reset the
interface, shut it down by entering the
shutdown command and then re-enable it by entering the no
shutdown
command.
4. To display the PE ports that are shut down due to loop detection, enter the show mac learning-
limit violate-action command.
Dell# show mac learning-limit violate-action
Interface Violation-Type Violate-Action Status
PeGi 0/2/47 Pe-Loop Shutdown PEloop-disable
PeGi 100/0/20 Pe-Loop Shutdown PEloop-disable
PeGi 255/0/47 Pe-Loop Shutdown PEloop-disable
Po 1 Pe-Loop Shutdown PEloop-disable
Po 100 Pe-Loop Shutdown PEloop-disable
5. To display the reason why the line protocol is down on a PE port or port channel, enter the show
interface command.
EXEC mode
Dell(conf-if-po-1)#do show interface port-channel 1
Port-channel 1 is up, line protocol is down(Pe Loop Detection)
778
Port Extenders (PEs)