Alcatel-Lucent OmniSwitch 10K - MAC Address Flapping

OmniSwitch OS6860/OS6900/OS10K Troubleshooting Guide Part No.032996-00 Rev.A
AOS Release 7.X and 8.X January 2015
Alcatel-Lucent Page 33 of 148
6860-> show spantree vlan 200
Spanning Tree Parameters for Vlan 200
Spanning Tree Status : ON,
Protocol : IEEE Rapid STP,
mode : Per VLAN (1 STP per Vlan),
Priority : 32768 (0x8000),
Bridge ID : 8000-e8:e7:32:ab:1c:57,
Designated Root : 8000-e8:e7:32:38:d0:c0,
Cost to Root Bridge : 4,
Root Port : 1/1/2,
Next Best Root Cost : 0,
Next Best Root Port : None,
TxHoldCount : 3,
Topology Changes : 7,
Topology age : 03:23:38,
Current Parameters (seconds)
Max Age = 20,
Forward Delay = 15,
Hello Time = 2
Parameters system uses when attempting to become root
System Max Age = 20,
System Forward Delay = 15,
System Hello Time = 2
To find out which port is receiving the TCNs, you can use below command.
-->su
SHASTA#-> pidof stpNi
2076
SHASTA#-> debug 2076 "call stpni_printStats(1,1)"
[Thread debugging using libthread_db enabled]
0x0f923db0 in ___newselect_nocancel () from /lib/tls/libc.so.6
--------------------------------------------------------------------------------------------
| RX | TX | AGGR BPDU
PORT| Bpdu RBpdu MBpdu Flg80 Flg01 TCN | Bpdu RBpdu MBpdu Flg80 Flg01 TCN | Rx Tx
--------------------------------------------------------------------------------------------
x01: 0 2 0 0 2 0 0 30 0 0 2 0 0 0
x03: 0 1 0 0 0 0 0 27 0 0 2 0 0 0
x12: 0 2 0 0 2 0 0 30 0 0 2 0 0 0
--------------------------------------------------------------------------------------------
$1 = 1
Refer the “Troubleshooting STP” chapter for detailed information on troubleshooting issues related to STP.
MAC Address Flapping
There are scenarios in which one or more MAC addresses flapping between two interfaces. MAC address
flapping is mostly caused by a layer 2 loop in the network (which are not detected by STP).
The command “show mac-learning mac-address <mac>” show if the MAC address is flapping between two
ports. Refer the bshell troubleshooting section for detailed information.
-> show mac-learning mac-address 00:13:72:19:5e:1f
Legend: Mac Address: * = address not valid,
Mac Address: & = duplicate static address,
Domain Vlan/SrvcId/ISId Mac Address Type Operation Interface
-----------+---------------------+-------------------+---------------+------------+----------
VLAN 10 00:13:72:19:5e:1f dynamic bridging 2/1/15
-> show mac-learning mac-address 00:13:72:19:5e:1f