09-14-2014 09:30 PM - edited 03-07-2019 08:45 PM
Hi All,
We try to create a new inter-office link. The new link is highlighted in red line below.
However, we keep received the flapping error message as follow. How can I troubleshot on this?
*Jan 4 19:05:04.850: %SW_MATM-4-MACFLAP_NOTIF: Host 28d2.4476.140a in vlan 17 is flapping between port Gi4/0/42 and port Gi4/0/44
*Jan 4 19:05:05.026: %SW_MATM-4-MACFLAP_NOTIF: Host 0013.2304.ea7f in vlan 25 is flapping between port Gi4/0/44 and port Gi4/0/42
*Jan 4 19:05:05.026: %SW_MATM-4-MACFLAP_NOTIF: Host 0013.2304.49e8 in vlan 25 is flapping between port Gi4/0/44 and port Gi4/0/42
*Jan 4 19:05:05.144: %SW_MATM-4-MACFLAP_NOTIF: Host 4055.3926.8dc1 in vlan 17 is flapping between port Gi4/0/44 and port Gi4/0/42
*Jan 4 19:05:05.144: %SW_MATM-4-MACFLAP_NOTIF: Host a01d.48f5.4a7b in vlan 17 is flapping between port Gi4/0/44 and port Gi4/0/42
*Jan 4 19:05:05.312: %SW_MATM-4-MACFLAP_NOTIF: Host 4055.3926.8dc1 in vlan 25 is flapping between port Gi4/0/42 and port Gi4/0/44
*Jan 4 19:05:05.312: %SW_MATM-4-MACFLAP_NOTIF: Host 4055.3926.8dc1 in vlan 2 is flapping between port Gi4/0/42 and port Gi4/0/44
*Jan 4 19:05:05.320: %SW_MATM-4-MACFLAP_NOTIF: Host 4055.3926.8dc1 in vlan 19 is flapping between port Gi4/0/44 and port Gi4/0/42
09-14-2014 09:39 PM
Hi,
Please share output of "show spanning-tree vlan 17" from switch SW03, SW04 ,SW40 amd SW85. Also check on all switches if you are seeing any unusual logs related to link flap or spanning tree flap.
Regards,
Akash
09-14-2014 11:07 PM
Hi Akash,
Thanks for replied. I only check the link flapping error on SW85 using console cable.
Please see below for the requested show spanning-tree vlan 17 result.
SW03# show spanning-tree vlan 17
VLAN0017
Spanning tree enabled protocol rstp
Root ID Priority 4113
Address 4055.3904.cc41
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 4113 (priority 4096 sys-id-ext 17)
Address 4055.3904.cc41
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po1 Desg FWD 1 128.4096 (vPC peer-link) Network P2p
Eth7/18 Desg FWD 19 128.914 P2p Peer(STP)
SW04# show spanning-tree vlan 17
VLAN0017
Spanning tree enabled protocol rstp
Root ID Priority 4113
Address 4055.3904.cc41
Cost 1
Port 4096 (port-channel1)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 8209 (priority 8192 sys-id-ext 17)
Address 4055.3926.8dc1
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po1 Root FWD 1 128.4096 (vPC peer-link) Network P2p
Eth7/17 Desg FWD 19 128.913 P2p Peer(STP)
SW40#show spanning-tree vlan 17
VLAN0017
Spanning tree enabled protocol ieee
Root ID Priority 4113
Address 4055.3904.cc41
Cost 20
Port 47 (GigabitEthernet0/47)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32785 (priority 32768 sys-id-ext 17)
Address 001b.0cb9.9c00
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi0/1 Desg FWD 4 128.1 Edge P2p
Gi0/2 Desg FWD 19 128.2 Edge P2p
Gi0/3 Desg FWD 4 128.3 Edge P2p
Gi0/4 Desg FWD 4 128.4 Edge P2p
Gi0/8 Desg FWD 4 128.8 Edge P2p
Gi0/16 Desg FWD 4 128.16 Edge P2p
Gi0/17 Desg FWD 4 128.17 Edge P2p
Gi0/18 Desg FWD 4 128.18 Edge P2p
Gi0/20 Desg FWD 4 128.20 Edge P2p
Gi0/21 Desg FWD 4 128.21 Edge P2p
Gi0/24 Desg FWD 19 128.24 Edge P2p
Gi0/25 Desg FWD 19 128.25 Edge P2p
Gi0/26 Desg FWD 19 128.26 Edge P2p
Gi0/27 Desg FWD 19 128.27 Edge P2p
Gi0/28 Desg FWD 4 128.28 Edge P2p
Gi0/29 Desg FWD 19 128.29 Edge P2p
Gi0/32 Desg FWD 4 128.32 Edge P2p
Gi0/33 Desg FWD 4 128.33 Edge P2p
Gi0/35 Desg FWD 4 128.35 Edge P2p
Gi0/37 Desg FWD 4 128.37 Edge P2p
Gi0/38 Desg FWD 4 128.38 Edge P2p
Gi0/40 Desg FWD 4 128.40 Edge P2p
Gi0/44 Desg FWD 4 128.44 Edge P2p
Gi0/45 Desg FWD 16384 128.45 P2p
Gi0/47 Root FWD 19 128.47 P2p
Gi0/49 Desg FWD 4 128.49 P2p
Gi0/50 Desg FWD 4 128.50 P2p
Gi0/52 Desg FWD 4 128.52 P2p
SW85#show spanning-tree vlan 17
VLAN0017
Spanning tree enabled protocol ieee
Root ID Priority 4113
Address 4055.3904.cc41
Cost 19
Port 204 (GigabitEthernet4/0/42)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32785 (priority 32768 sys-id-ext 17)
Address e05f.b9da.e780
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi1/1/1 Desg FWD 4 128.49 P2p
Gi3/1/1 Desg FWD 4 128.157 P2p
Gi3/1/2 Desg FWD 4 128.158 P2p
Gi4/0/42 Root FWD 19 128.204 P2p
09-14-2014 11:24 PM
Hi,
As of now you have shut down the port Gig4/0/44 and that is why it is loop free topology and all ports are either in Desg FWD or Root FWD. When all links are up, one link should be in blocking mode. I believe host whose mac is flapping (for exa. 28d2.4476.140a) nust be connected below SW40,(to one of SW41,SW42,SW43 or SW44). When frame comes to SW40, it should be received to SW85, either on Gig4/0/42 or Gig4/0/44. One path should be blocked status.
You can unshut link Gig40/44 on SW85 during MW and check status of spanning tree on all vlans. Any recent changes in topology or port-channel/VPC on nexus switches?
Regards,
Akash
09-14-2014 11:28 PM
Hi Akash,
There is no recent changes to the nexus switches. We are trying to implement a backup redundant link in case the main link is down.
Sorry to ask, what do you mean by MW?
09-14-2014 11:32 PM
MW = Maintenance window.
09-14-2014 11:37 PM
Noted that. I have enabled and capture the configuration result. Please see below. It is in Desg mode and not block. Can i manually change it to block mode?
SW03# show spanning-tree vlan 17
VLAN0017
Spanning tree enabled protocol rstp
Root ID Priority 4113
Address 4055.3904.cc41
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 4113 (priority 4096 sys-id-ext 17)
Address 4055.3904.cc41
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po1 Desg FWD 1 128.4096 (vPC peer-link) Network P2p
Eth7/18 Desg FWD 19 128.914 P2p Peer(STP)
SW04# show spanning-tree vlan 17
VLAN0017
Spanning tree enabled protocol rstp
Root ID Priority 4113
Address 4055.3904.cc41
Cost 1
Port 4096 (port-channel1)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 8209 (priority 8192 sys-id-ext 17)
Address 4055.3926.8dc1
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po1 Root FWD 1 128.4096 (vPC peer-link) Network P2p
Eth7/17 Desg FWD 19 128.913 P2p Peer(STP)
SW40#show spanning-tree vlan 17
VLAN0017
Spanning tree enabled protocol ieee
Root ID Priority 4113
Address 4055.3904.cc41
Cost 20
Port 47 (GigabitEthernet0/47)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32785 (priority 32768 sys-id-ext 17)
Address 001b.0cb9.9c00
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 15
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi0/1 Desg FWD 4 128.1 Edge P2p
Gi0/2 Desg FWD 19 128.2 Edge P2p
Gi0/3 Desg FWD 4 128.3 Edge P2p
Gi0/4 Desg FWD 4 128.4 Edge P2p
Gi0/8 Desg FWD 4 128.8 Edge P2p
Gi0/17 Desg FWD 4 128.17 Edge P2p
Gi0/18 Desg FWD 4 128.18 Edge P2p
Gi0/20 Desg FWD 4 128.20 Edge P2p
Gi0/21 Desg FWD 4 128.21 Edge P2p
Gi0/24 Desg FWD 19 128.24 Edge P2p
Gi0/25 Desg FWD 19 128.25 Edge P2p
Gi0/26 Desg FWD 19 128.26 Edge P2p
Gi0/27 Desg FWD 19 128.27 Edge P2p
Gi0/28 Desg FWD 4 128.28 Edge P2p
Gi0/29 Desg FWD 19 128.29 Edge P2p
Gi0/32 Desg FWD 4 128.32 Edge P2p
Gi0/35 Desg FWD 4 128.35 Edge P2p
Gi0/37 Desg FWD 4 128.37 Edge P2p
Gi0/38 Desg FWD 4 128.38 Edge P2p
Gi0/40 Desg FWD 4 128.40 Edge P2p
Gi0/42 Desg FWD 4 128.42 Edge P2p
Gi0/43 Desg FWD 19 128.43 Edge P2p
Gi0/44 Desg FWD 4 128.44 Edge P2p
Gi0/45 Desg FWD 16384 128.45 P2p
Gi0/47 Root FWD 19 128.47 P2p
Gi0/49 Desg FWD 4 128.49 P2p
Gi0/50 Desg FWD 4 128.50 P2p
Gi0/52 Desg FWD 4 128.52 P2p
SW85# show spanning-tree vlan 17
VLAN0017
Spanning tree enabled protocol ieee
Root ID Priority 4113
Address 4055.3904.cc41
Cost 19
Port 204 (GigabitEthernet4/0/42)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32785 (priority 32768 sys-id-ext 17)
Address e05f.b9da.e780
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 15 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi1/1/1 Desg FWD 4 128.49 P2p
Gi3/1/1 Desg FWD 4 128.157 P2p
Gi3/1/2 Desg FWD 4 128.158 P2p
Gi4/0/42 Root FWD 19 128.204 P2p
Gi4/0/44 Desg FWD 16384 128.206 P2p
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