Mac flap between normal ports Port channel

[surjinp07@]

Hi

i am facing the issue in our network .my network structure

 Network configuration

A 200Mb internet connection terminates on a Ubiquiti USG-PRO-4 Cloud Managed UniFi Security Gateway PRO Broadband Router (https://www.ui.com/unifi-routing/unifi-security-gateway-pro-4/)

This is uplinked via RJ45 in the ground floor hub to:

• Catalyst 3650 Router, which in turn has 5 x 9200 switches uplinked to it.

There is a dual fibre etherchannel connection to the 1st floor hub room:

• Catalyst 3850 Router, which has 4 x 9200 switches uplinked t it.

Currently there is a single network for end user devices of 172.16.x.x (termed the Lab network) and all DHCP services are provided by the Unify gateway. This also supports a single Unify wireless network

There is a small server farm consisting of 2 x HPE DL360 hosts running VMware v7 with direct fibre attached HPE MSA storage array in the ground floor hub room.

There is an additional DL380 running VM with local disk storage for backup/failover in the 1st floor hub

The work required to complete the installation  (based on initial thoughts):

• Create a management VLAN for the switches on 192.168.159.x
• Create a VLAN for the VMware ESXi hosts on 192.168.169.x
• Create a VLAN for the local Chilworth AD domain on 192.168.179.x
• Create a DHCP server on the 192 network for  Chilworth devices

There is a spare physical port on the Unify Gateway so the idea was to have the Lab network 172.16.x.x on Port 1 and the local Chilworth domain and management networks 192.168.x.x on Port 2 - there may be a 3rd port of the Unify for the management network but would have to clarify.

We would configure additional 9200 switches to serve up the 192 network rather than have individual ports on the existing switches.

We would also create additional wireless networks and separate out Lab and Chilworth (guest) devices by SSID

The plan would be to isolate outbound traffic on the 172 network to specified external hosts (may need a proxy server for this) and allow full outbound access from the 192 network.

So in essence, the 172 Lab network would stay largely as is and we would migrate non-Lab devices  to the 192 network

As said on the call, the assumption is the Unify Gateway will control the routing but that could be further investigated and advised upon.

Aug 8 15:01:49.808: %SW_MATM-4-MACFLAP_NOTIF: Host 68ec.c52a.604d in vlan 1 is flapping between port Gi1/0/12 and port Po1
*Aug 8 15:01:50.108: %SW_MATM-4-MACFLAP_NOTIF: Host 0050.56a9.77c6 in vlan 1 is flapping between port Gi1/0/35 and port Po1
*Aug 8 15:01:50.272: %SW_MATM-4-MACFLAP_NOTIF: Host c8f7.50f8.b1a1 in vlan 1 is flapping between port Gi1/0/23 and port Po1
*Aug 8 15:01:50.291: %SW_MATM-4-MACFLAP_NOTIF: Host 0050.56a9.bcba in vlan 1 is flapping between port Gi1/0/43 and port Po1
*Aug 8 15:01:50.333: %SW_MATM-4-MACFLAP_NOTIF: Host e0d4.64d0.e206 in vlan 1 is flapping between port Gi1/0/10 and port Po1
*Aug 8 15:01:50.556: %SW_MATM-4-MACFLAP_NOTIF: Host 0050.56a9.ac55 in vlan 1 is flapping between port Gi1/0/39 and port Po1
*Aug 8 15:01:50.604: %SW_MATM-4-MACFLAP_NOTIF: Host 6854.5ac7.9278 in vlan 1 is flapping between port Gi1/0/13 and port Po1
*Aug 8 15:01:50.730: %SW_MATM-4-MACFLAP_NOTIF: Host a4bb.6ddc.30ce in vlan 1 is flapping between port Gi1/0/32 and port Po1
*Aug 8 15:01:51.646: %SW_MATM-4-MACFLAP_NOTIF: Host e063.daac.f5ba in vlan 1 is flapping between port Gi1/0/8 and port Po1
*Aug 8 15:01:52.123: %SW_MATM-4-MACFLAP_NOTIF: Host e063.daa9.eef0 in vlan 1 is flapping between port Gi1/0/5 and port Po1
*Aug 8 15:01:52.498: %SW_MATM-4-MACFLAP_NOTIF: Host e063.daa9.f1f5 in vlan 1 is flapping between port Gi1/0/16 and port Po1
*Aug 8 15:01:52.573: %SW_MATM-4-MACFLAP_NOTIF: Host e063.daac.f742 in vlan 1 is flapping between port Gi1/0/15 and port Po1
*Aug 8 15:01:52.929: %SW_MATM-4-MACFLAP_NOTIF: Host e063.daac.f4f2 in vlan 1 is flapping between port Gi1/0/10 and port Po1
*Aug 8 15:01:53.213: %SW_MATM-4-MACFLAP_NOTIF: Host e063.daac.cc0d in vlan 1 is flapping between port Gi1/0/12 and port Po1
*Aug 8 15:01:53.714: %SW_MATM-4-MACFLAP_NOTIF: Host e0d4.64ee.a8f9 in vlan 1 is flapping between port Gi1/0/7 and port Po1
*Aug 8 15:01:53.848: %SW_MATM-4-MACFLAP_NOTIF: Host a4bb.6dd0.24a5 in vlan 1 is flapping between port Gi1/0/34 and port Po1
*Aug 8 15:02:03.640: %SW_MATM-4-MACFLAP_NOTIF: Host 0050.56a9.304a in vlan 1 is flapping between port Gi1/0/35 and port Po1
*Aug 8 15:02:03.656: %SW_MATM-4-MACFLAP_NOTIF: Host e063.dace.b821 in vlan 1 is flapping between port Gi1/0/48 and port Po1
*Aug 8 15:02:03.688: %SW_MATM-4-MACFLAP_NOTIF: Host 0050.56a9.a1fe in vlan 1 is flapping between port Gi1/0/39 and port Po1
*Aug 8 15:02:03.704: %SW_MATM-4-MACFLAP_NOTIF: Host c8f7.50fc.bc45 in vlan 1 is flapping between port Gi1/0/34 and port Po1
*Aug 8 15:02:03.767: %SW_MATM-4-MACFLAP_NOTIF: Host a4bb.6ddc.2699 in vlan 1 is flapping between port Gi1/0/38 and port Po1
*Aug 8 15:02:03.892: %SW_MATM-4-MACFLAP_NOTIF: Host e063.daac.f512 in vlan 1 is flapping between port Po1 and port Gi1/0/6
*Aug 8 15:02:03.974: %SW_MATM-4-MACFLAP_NOTIF: Host e063.daac.cc0d in vlan 1 is flapping between port Gi1/0/12 and port Po1
*Aug 8 15:02:04.079: %SW_MATM-4-MACFLAP_NOTIF: Host c8f7.50fb.c3f3 in vlan 1 is flapping between port Gi1/0/32 and port Po1
*Aug 8 15:02:04.234: %SW_MATM-4-MACFLAP_NOTIF: Host e454.e895.92d2 in vlan 1 is flapping between port Po1 and port Gi1/0/34
*Aug 8 15:02:04.296: %SW_MATM-4-MACFLAP_NOTIF: Host c8f7.50f8.b1a1 in vlan 1 is flapping between port Gi1/0/23 and port Po1
*Aug 8 15:02:04.555: %SW_MATM-4-MACFLAP_NOTIF: Host 6854.5ac7.9278 in vlan 1 is flapping between port Gi1/0/13 and port Po1
*Aug 8 15:02:04.560: %SW_MATM-4-MACFLAP_NOTIF: Host 0050.56a9.f8fa in vlan 1 is flapping between port Gi1/0/39 and port Po1
*Aug 8 15:02:04.860: %SW_MATM-4-MACFLAP_NOTIF: Host 0050.56a9.ac55 in vlan 1 is flapping between port Gi1/0/39 and port Po1
*Aug 8 15:02:04.927: %SW_MATM-4-MACFLAP_NOTIF: Host a4bb.6dd0.24a5 in vlan 1 is flapping between port Gi1/0/34 and port Po1
*Aug 8 15:02:04.931: %SW_MATM-4-MACFLAP_NOTIF: Host e0d4.64d0.e206 in vlan 1 is flapping between port Gi1/0/10 and port Po1
*Aug 8 15:02:05.170: %SW_MATM-4-MACFLAP_NOTIF: Host a4bb.6ddc.321a in vlan 1 is flapping between port Gi1/0/38 and port Po1
*Aug 8 15:02:05.404: %SW_MATM-4-MACFLAP_NOTIF: Host a4bb.6ddc.30ce in vlan 1 is flapping between port Gi1/0/32 and port Po1
*Aug 8 15:02:05.741: %SW_MATM-4-MACFLAP_NOTIF: Host e063.daa9.f1f5 in vlan 1 is flapping between port Gi1/0/16 and port Po1
*Aug 8 15:02:05.953: %SW_MATM-4-MACFLAP_NOTIF: Host 68ec.c52a.604d in vlan 1 is flapping between port Gi1/0/12 and port Po1
*Aug 8 15:02:05.985: %SW_MATM-4-MACFLAP_NOTIF: Host 0050.56a9.77c6 in vlan 1 is flapping between port Gi1/0/35 and port Po1
*Aug 8 15:02:06.270: %SW_MATM-4-MACFLAP_NOTIF: Host e0d4.64ee.a8f9 in vlan 1 is flapping between port Gi1/0/7 and port Po1
*Aug 8 15:02:06.436: %SW_MATM-4-MACFLAP_NOTIF: Host e063.daac.ca86 in vlan 1 is flapping between port Gi1/0/9 and port Po1
*Aug 8 15:02:06.940: %SW_MATM-4-MACFLAP_NOTIF: Host e063.daac.f5ba in vlan 1 is flapping between port Gi1/0/8 and port Po1
*Aug 8 15:02:07.624: %SW_MATM-4-MACFLAP_NOTIF: Host e063.daa9.eef0 in vlan 1 is flapping between port Gi1/0/5 and port Po1
*Aug 8 15:02:08.027: %SW_MATM-4-MACFLAP_NOTIF: Host e063.daac.f4f2 in vlan 1 is flapping between port Gi1/0/10 and port Po1
*Aug 8 15:02:08.693: %SW_MATM-4-MACFLAP_NOTIF: Host e063.daac.f742 in vlan 1 is flapping between port Gi1/0/15 and port Po1
*Aug 9 05:10:24.798: %SW_MATM-4-MACFLAP_NOTIF: Host 108e.e057.6610 in vlan 1 is flapping between port Gi1/0/12 and port Gi1/0/10

what willl be issue kindly give me suggestion

[surjinp07@]

all these macflap happen in our core switches .there is no macflap or errors in other switches

[Giuseppe Larosa]

Hello surjinp07@ ,

verify what is happenining for STP for VLAN 1

use ( here I suppose you are using PVST or Rapid PVST)

show spanning-tree vlan 1 detail

see if the number of Topology Changes increases over time and if the root bridge ID change

( repeat the suggested command every few minutes)

check this on both core switches  and pay attention if both are claiming to be root bridge for VLAN 1 at the same time.

Hope to help

Giuseppe

[surjinp07@]

Hi

It is rapid pvst . what is the solution for this, now it have some packet drops also. mainly all the macflap happining in wireless AP port before. now almost every port having the issue.

[surjinp07@]

hi

this my interface configuration.

interface Port-channel1
description Uplink to CHILWORTH-UPSTAIRS-CORE
switchport mode trunk
!
interface GigabitEthernet0/0
vrf forwarding Mgmt-vrf
no ip address
shutdown
negotiation auto
!
interface GigabitEthernet1/0/1
spanning-tree portfast
!
interface GigabitEthernet1/0/2
description Firewall Uplink LAN3
switchport mode trunk
!
interface GigabitEthernet1/0/3
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/4
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/5
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/6
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/7
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/8
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/9
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/10
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/11
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/12
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/13
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/14
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/15
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/16
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/17
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/18
description Wireless AP's
switchport mode trunk
!
interface GigabitEthernet1/0/19
spanning-tree portfast
!
interface GigabitEthernet1/0/20
description Storage
switchport access vlan 169
spanning-tree portfast
!
interface GigabitEthernet1/0/21
spanning-tree portfast
!
interface GigabitEthernet1/0/22
description Storage
switchport access vlan 169
spanning-tree portfast
!
interface GigabitEthernet1/0/23
description Uplink to CHILWORTH-L-06
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet1/0/24
spanning-tree portfast
!
interface GigabitEthernet1/0/25
spanning-tree portfast
!
interface GigabitEthernet1/0/26
description Uplink to CHILWORTH-L-07
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet1/0/27
spanning-tree portfast
!
interface GigabitEthernet1/0/28
description Firewall Uplink LAN2
switchport mode trunk
!
interface GigabitEthernet1/0/29
spanning-tree portfast
!
interface GigabitEthernet1/0/30
description Uplink to CHILWORTH-L-05
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet1/0/31
spanning-tree portfast
!
interface GigabitEthernet1/0/32
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet1/0/33
description VMware
switchport mode trunk
!
interface GigabitEthernet1/0/34
description Uplink to CHILWORTH-L-03
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet1/0/35
description VMware
switchport mode trunk
!
interface GigabitEthernet1/0/36
spanning-tree portfast
!
interface GigabitEthernet1/0/37
description VMware
switchport mode trunk
!
interface GigabitEthernet1/0/38
description Uplink to CHILWORTH-L-02
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet1/0/39
description VMware
switchport mode trunk
!
interface GigabitEthernet1/0/40
spanning-tree portfast
!
interface GigabitEthernet1/0/41
description VMware
switchport mode trunk
!
interface GigabitEthernet1/0/42
spanning-tree portfast
!
interface GigabitEthernet1/0/43
description VMware
switchport mode trunk
!
interface GigabitEthernet1/0/44
spanning-tree portfast
!
interface GigabitEthernet1/0/45
description VMware
switchport mode trunk
!
interface GigabitEthernet1/0/46
description Uplink to CHILWORTH-L-01
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet1/0/47
description VMware
switchport mode trunk
!
interface GigabitEthernet1/0/48
!
interface GigabitEthernet1/1/1
description Uplink to CHILWORTH-UPSTAIRS-CORE
channel-group 1 mode active
!
interface GigabitEthernet1/1/2
!
interface GigabitEthernet1/1/3
!
interface GigabitEthernet1/1/4
description Uplink to CHILWORTH-UPSTAIRS-CORE
switchport mode trunk
channel-group 1 mode active
!
interface Vlan1
no ip address
shutdown
!
interface Vlan159
ip address 192.168.159.11 255.255.255.0
!
ip default-gateway 192.168.159.1
ip forward-protocol nd
no ip http server
ip http authentication local
no ip http secure-server
!
!
!
!
snmp-server community monitoting RO
snmp-server location Chilworth
!
control-plane
service-policy input system-cpp-policy
!
!
line con 0
exec-timeout 0 0
login local
stopbits 1
line aux 0
stopbits 1
line vty 0 4
login local
transport input ssh
line vty 5 15
login local
transport input ssh
!
!
!
!
!
!

[Giuseppe Larosa]

Hello surjinp07@ ,

post output of

show spanning-tree vlan 1 detail

taken on both core switches.

do it more times every 5 minutes and let us see if the number of topology changes is increasing.

Hope to help

Giuseppe

[surjinp07@]

hi

this is the output for both switches

CHILWORTH-UPSTAIRS-CORE#show spanning-tree vlan 1

VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 1
Address b838.613a.6180
Cost 3
Port 2027 (Port-channel1)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 8193 (priority 8192 sys-id-ext 1)
Address 0c68.0345.1b80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi1/0/1 Desg FWD 4 128.1 P2p Edge
Gi1/0/3 Desg FWD 4 128.3 P2p Edge
Gi1/0/4 Desg FWD 19 128.4 P2p Edge
Gi1/0/5 Desg FWD 4 128.5 P2p
Gi1/0/6 Desg FWD 4 128.6 P2p
Gi1/0/7 Desg FWD 19 128.7 P2p
Gi1/0/12 Desg FWD 4 128.12 P2p
Gi1/0/13 Desg FWD 4 128.13 P2p
Gi1/0/14 Desg FWD 4 128.14 P2p
Gi1/0/15 Desg FWD 4 128.15 P2p
Gi1/0/16 Desg FWD 4 128.16 P2p
Gi1/0/21 Desg FWD 4 128.21 P2p
Gi1/0/22 Desg FWD 4 128.22 P2p
Gi1/0/23 Desg FWD 4 128.23 P2p
Gi1/0/24 Desg FWD 4 128.24 P2p
Po1 Root FWD 3 128.2027 P2p

CHILWORTH-UPSTAIRS-CORE#show spanning-tree vlan 1

VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 1
Address b838.613a.6180
Cost 3
Port 2027 (Port-channel1)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 8193 (priority 8192 sys-id-ext 1)
Address 0c68.0345.1b80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi1/0/1 Desg FWD 4 128.1 P2p Edge
Gi1/0/3 Desg FWD 4 128.3 P2p Edge
Gi1/0/4 Desg FWD 19 128.4 P2p Edge
Gi1/0/5 Desg FWD 4 128.5 P2p
Gi1/0/6 Desg FWD 4 128.6 P2p
Gi1/0/7 Desg FWD 19 128.7 P2p
Gi1/0/12 Desg FWD 4 128.12 P2p
Gi1/0/13 Desg FWD 4 128.13 P2p
Gi1/0/14 Desg FWD 4 128.14 P2p
Gi1/0/15 Desg FWD 4 128.15 P2p
Gi1/0/16 Desg FWD 4 128.16 P2p
Gi1/0/21 Desg FWD 4 128.21 P2p
Gi1/0/22 Desg FWD 4 128.22 P2p
Gi1/0/23 Desg FWD 4 128.23 P2p
Gi1/0/24 Desg FWD 4 128.24 P2p
Po1 Root FWD 3 128.2027 P2p

CHILWORTH-UPSTAIRS-CORE#show spanning-tree vlan 1

VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 1
Address b838.613a.6180
Cost 3
Port 2027 (Port-channel1)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 8193 (priority 8192 sys-id-ext 1)
Address 0c68.0345.1b80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi1/0/1 Desg FWD 4 128.1 P2p Edge
Gi1/0/3 Desg FWD 4 128.3 P2p Edge
Gi1/0/4 Desg FWD 19 128.4 P2p Edge
Gi1/0/5 Desg FWD 4 128.5 P2p
Gi1/0/6 Desg FWD 4 128.6 P2p
Gi1/0/7 Desg FWD 19 128.7 P2p
Gi1/0/12 Desg FWD 4 128.12 P2p

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------

Gi1/0/13 Desg FWD 4 128.13 P2p
Gi1/0/14 Desg FWD 4 128.14 P2p
Gi1/0/15 Desg FWD 4 128.15 P2p
Gi1/0/16 Desg FWD 4 128.16 P2p
Gi1/0/21 Desg FWD 4 128.21 P2p
Gi1/0/22 Desg FWD 4 128.22 P2p
Gi1/0/23 Desg FWD 4 128.23 P2p
Gi1/0/24 Desg FWD 4 128.24 P2p
Po1 Root FWD 3 128.2027 P2p

CHILWORTH-UPSTAIRS-CORE#show spanning-tree vlan 1

VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 1
Address b838.613a.6180
Cost 3
Port 2027 (Port-channel1)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 8193 (priority 8192 sys-id-ext 1)
Address 0c68.0345.1b80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi1/0/1 Desg FWD 4 128.1 P2p Edge
Gi1/0/3 Desg FWD 4 128.3 P2p Edge
Gi1/0/4 Desg FWD 19 128.4 P2p Edge
Gi1/0/5 Desg FWD 4 128.5 P2p
Gi1/0/6 Desg FWD 4 128.6 P2p
Gi1/0/7 Desg FWD 19 128.7 P2p
Gi1/0/12 Desg FWD 4 128.12 P2p

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------

Gi1/0/13 Desg FWD 4 128.13 P2p
Gi1/0/14 Desg FWD 4 128.14 P2p
Gi1/0/15 Desg FWD 4 128.15 P2p
Gi1/0/16 Desg FWD 4 128.16 P2p
Gi1/0/21 Desg FWD 4 128.21 P2p
Gi1/0/22 Desg FWD 4 128.22 P2p
Gi1/0/23 Desg FWD 4 128.23 P2p
Gi1/0/24 Desg FWD 4 128.24 P2p
Po1 Root FWD 3 128.2027 P2p

CHILWORTH-UPSTAIRS-CORE#show spanning-tree vlan 1

VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 1
Address b838.613a.6180
Cost 3
Port 2027 (Port-channel1)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 8193 (priority 8192 sys-id-ext 1)
Address 0c68.0345.1b80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi1/0/1 Desg FWD 4 128.1 P2p Edge
Gi1/0/3 Desg FWD 4 128.3 P2p Edge
Gi1/0/4 Desg FWD 19 128.4 P2p Edge
Gi1/0/5 Desg FWD 4 128.5 P2p
Gi1/0/6 Desg FWD 4 128.6 P2p
Gi1/0/7 Desg FWD 19 128.7 P2p
Gi1/0/12 Desg FWD 4 128.12 P2p

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------

Gi1/0/13 Desg FWD 4 128.13 P2p
Gi1/0/14 Desg FWD 4 128.14 P2p
Gi1/0/15 Desg FWD 4 128.15 P2p
Gi1/0/16 Desg FWD 4 128.16 P2p
Gi1/0/21 Desg FWD 4 128.21 P2p
Gi1/0/22 Desg FWD 4 128.22 P2p
Gi1/0/23 Desg FWD 4 128.23 P2p
Gi1/0/24 Desg FWD 4 128.24 P2p
Po1 Root FWD 3 128.2027 P2p

***********************************************************
***********************************************************
********************************************************

CLILWORTH-DOWNSTAIRS-CORE#show spanning-tree vlan 1

VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 1
Address b838.613a.6180
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 1 (priority 0 sys-id-ext 1)
Address b838.613a.6180
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi1/0/2 Desg FWD 4 128.2 P2p
Gi1/0/3 Desg FWD 4 128.3 P2p
Gi1/0/4 Desg FWD 4 128.4 P2p
Gi1/0/5 Desg FWD 19 128.5 P2p
Gi1/0/6 Desg FWD 4 128.6 P2p
Gi1/0/7 Desg FWD 4 128.7 P2p
Gi1/0/8 Desg FWD 4 128.8 P2p
Gi1/0/9 Desg FWD 4 128.9 P2p
Gi1/0/10 Desg FWD 19 128.10 P2p
Gi1/0/11 Desg FWD 4 128.11 P2p
Gi1/0/12 Desg FWD 4 128.12 P2p
Gi1/0/13 Desg FWD 4 128.13 P2p
Gi1/0/15 Desg FWD 4 128.15 P2p
Gi1/0/16 Desg FWD 4 128.16 P2p
Gi1/0/23 Desg FWD 4 128.23 P2p
Gi1/0/25 Desg FWD 19 128.25 P2p Edge
Gi1/0/26 Desg FWD 4 128.26 P2p
Gi1/0/27 Desg FWD 19 128.27 P2p Edge
Gi1/0/28 Desg FWD 4 128.28 P2p
Gi1/0/30 Desg FWD 4 128.30 P2p
Gi1/0/32 Desg FWD 4 128.32 P2p
Gi1/0/33 Desg FWD 4 128.33 P2p
Gi1/0/34 Desg FWD 4 128.34 P2p
Gi1/0/35 Desg FWD 4 128.35 P2p
Gi1/0/37 Desg FWD 4 128.37 P2p
Gi1/0/38 Desg FWD 4 128.38 P2p
Gi1/0/39 Desg FWD 4 128.39 P2p
Gi1/0/41 Desg FWD 4 128.41 P2p
Gi1/0/43 Desg FWD 4 128.43 P2p
Gi1/0/45 Desg FWD 4 128.45 P2p
Gi1/0/46 Desg FWD 4 128.46 P2p
Gi1/0/47 Desg FWD 4 128.47 P2p
Gi1/0/48 Desg FWD 4 128.48 P2p
Po1 Desg FWD 3 128.2377 P2p

CLILWORTH-DOWNSTAIRS-CORE#show spanning-tree vlan 1

VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 1
Address b838.613a.6180
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 1 (priority 0 sys-id-ext 1)
Address b838.613a.6180
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi1/0/2 Desg FWD 4 128.2 P2p
Gi1/0/3 Desg FWD 4 128.3 P2p
Gi1/0/4 Desg FWD 4 128.4 P2p
Gi1/0/5 Desg FWD 19 128.5 P2p
Gi1/0/6 Desg FWD 4 128.6 P2p
Gi1/0/7 Desg FWD 4 128.7 P2p
Gi1/0/8 Desg FWD 4 128.8 P2p
Gi1/0/9 Desg FWD 4 128.9 P2p
Gi1/0/10 Desg FWD 19 128.10 P2p
Gi1/0/11 Desg FWD 4 128.11 P2p
Gi1/0/12 Desg FWD 4 128.12 P2p
Gi1/0/13 Desg FWD 4 128.13 P2p
Gi1/0/15 Desg FWD 4 128.15 P2p
Gi1/0/16 Desg FWD 4 128.16 P2p
Gi1/0/23 Desg FWD 4 128.23 P2p
Gi1/0/25 Desg FWD 19 128.25 P2p Edge
Gi1/0/26 Desg FWD 4 128.26 P2p
Gi1/0/27 Desg FWD 19 128.27 P2p Edge
Gi1/0/28 Desg FWD 4 128.28 P2p
Gi1/0/30 Desg FWD 4 128.30 P2p
Gi1/0/32 Desg FWD 4 128.32 P2p
Gi1/0/33 Desg FWD 4 128.33 P2p
Gi1/0/34 Desg FWD 4 128.34 P2p
Gi1/0/35 Desg FWD 4 128.35 P2p
Gi1/0/37 Desg FWD 4 128.37 P2p
Gi1/0/38 Desg FWD 4 128.38 P2p
Gi1/0/39 Desg FWD 4 128.39 P2p
Gi1/0/41 Desg FWD 4 128.41 P2p
Gi1/0/43 Desg FWD 4 128.43 P2p
Gi1/0/45 Desg FWD 4 128.45 P2p
Gi1/0/46 Desg FWD 4 128.46 P2p
Gi1/0/47 Desg FWD 4 128.47 P2p
Gi1/0/48 Desg FWD 4 128.48 P2p
Po1 Desg FWD 3 128.2377 P2p

CLILWORTH-DOWNSTAIRS-CORE#

CLILWORTH-DOWNSTAIRS-CORE#show spanning-tree vlan 1

VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 1
Address b838.613a.6180
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 1 (priority 0 sys-id-ext 1)
Address b838.613a.6180
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi1/0/2 Desg FWD 4 128.2 P2p
Gi1/0/3 Desg FWD 4 128.3 P2p
Gi1/0/4 Desg FWD 4 128.4 P2p
Gi1/0/5 Desg FWD 19 128.5 P2p
Gi1/0/6 Desg FWD 4 128.6 P2p
Gi1/0/7 Desg FWD 4 128.7 P2p
Gi1/0/8 Desg FWD 4 128.8 P2p
Gi1/0/9 Desg FWD 4 128.9 P2p
Gi1/0/10 Desg FWD 19 128.10 P2p
Gi1/0/11 Desg FWD 4 128.11 P2p
Gi1/0/12 Desg FWD 4 128.12 P2p
Gi1/0/13 Desg FWD 4 128.13 P2p
Gi1/0/15 Desg FWD 4 128.15 P2p
Gi1/0/16 Desg FWD 4 128.16 P2p
Gi1/0/23 Desg FWD 4 128.23 P2p
Gi1/0/25 Desg FWD 19 128.25 P2p Edge
Gi1/0/26 Desg FWD 4 128.26 P2p
Gi1/0/27 Desg FWD 19 128.27 P2p Edge
Gi1/0/28 Desg FWD 4 128.28 P2p
Gi1/0/30 Desg FWD 4 128.30 P2p
Gi1/0/32 Desg FWD 4 128.32 P2p
Gi1/0/33 Desg FWD 4 128.33 P2p
Gi1/0/34 Desg FWD 4 128.34 P2p
Gi1/0/35 Desg FWD 4 128.35 P2p
Gi1/0/37 Desg FWD 4 128.37 P2p
Gi1/0/38 Desg FWD 4 128.38 P2p
Gi1/0/39 Desg FWD 4 128.39 P2p
Gi1/0/41 Desg FWD 4 128.41 P2p
Gi1/0/43 Desg FWD 4 128.43 P2p
Gi1/0/45 Desg FWD 4 128.45 P2p
Gi1/0/46 Desg FWD 4 128.46 P2p
Gi1/0/47 Desg FWD 4 128.47 P2p
Gi1/0/48 Desg FWD 4 128.48 P2p
Po1 Desg FWD 3 128.2377 P2p

LILWORTH-DOWNSTAIRS-CORE#show spanning-tree vlan 1

VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 1
Address b838.613a.6180
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 1 (priority 0 sys-id-ext 1)
Address b838.613a.6180
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi1/0/2 Desg FWD 4 128.2 P2p
Gi1/0/3 Desg FWD 4 128.3 P2p
Gi1/0/4 Desg FWD 4 128.4 P2p
Gi1/0/5 Desg FWD 19 128.5 P2p
Gi1/0/6 Desg FWD 4 128.6 P2p
Gi1/0/7 Desg FWD 4 128.7 P2p
Gi1/0/8 Desg FWD 4 128.8 P2p
Gi1/0/9 Desg FWD 4 128.9 P2p
Gi1/0/10 Desg FWD 19 128.10 P2p
Gi1/0/11 Desg FWD 4 128.11 P2p
Gi1/0/12 Desg FWD 4 128.12 P2p
Gi1/0/13 Desg FWD 4 128.13 P2p
Gi1/0/15 Desg FWD 4 128.15 P2p
Gi1/0/16 Desg FWD 4 128.16 P2p
Gi1/0/23 Desg FWD 4 128.23 P2p
Gi1/0/25 Desg FWD 19 128.25 P2p Edge
Gi1/0/26 Desg FWD 4 128.26 P2p
Gi1/0/27 Desg FWD 19 128.27 P2p Edge
Gi1/0/28 Desg FWD 4 128.28 P2p
Gi1/0/30 Desg FWD 4 128.30 P2p
Gi1/0/32 Desg FWD 4 128.32 P2p
Gi1/0/33 Desg FWD 4 128.33 P2p
Gi1/0/34 Desg FWD 4 128.34 P2p
Gi1/0/35 Desg FWD 4 128.35 P2p
Gi1/0/37 Desg FWD 4 128.37 P2p
Gi1/0/38 Desg FWD 4 128.38 P2p
Gi1/0/39 Desg FWD 4 128.39 P2p
Gi1/0/41 Desg FWD 4 128.41 P2p
Gi1/0/43 Desg FWD 4 128.43 P2p
Gi1/0/45 Desg FWD 4 128.45 P2p
Gi1/0/46 Desg FWD 4 128.46 P2p
Gi1/0/47 Desg FWD 4 128.47 P2p
Gi1/0/48 Desg FWD 4 128.48 P2p
Po1 Desg FWD 3 128.2377 P2p

CLILWORTH-DOWNSTAIRS-CORE#show spanning-tree vlan 1

VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 1
Address b838.613a.6180
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 1 (priority 0 sys-id-ext 1)
Address b838.613a.6180
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi1/0/2 Desg FWD 4 128.2 P2p
Gi1/0/3 Desg FWD 4 128.3 P2p
Gi1/0/4 Desg FWD 4 128.4 P2p
Gi1/0/5 Desg FWD 19 128.5 P2p
Gi1/0/6 Desg FWD 4 128.6 P2p
Gi1/0/7 Desg FWD 4 128.7 P2p
Gi1/0/8 Desg FWD 4 128.8 P2p
Gi1/0/9 Desg FWD 4 128.9 P2p
Gi1/0/10 Desg FWD 19 128.10 P2p
Gi1/0/11 Desg FWD 4 128.11 P2p
Gi1/0/12 Desg FWD 4 128.12 P2p
Gi1/0/13 Desg FWD 4 128.13 P2p
Gi1/0/15 Desg FWD 4 128.15 P2p
Gi1/0/16 Desg FWD 4 128.16 P2p
Gi1/0/23 Desg FWD 4 128.23 P2p
Gi1/0/25 Desg FWD 19 128.25 P2p Edge
Gi1/0/26 Desg FWD 4 128.26 P2p
Gi1/0/27 Desg FWD 19 128.27 P2p Edge
Gi1/0/28 Desg FWD 4 128.28 P2p
Gi1/0/30 Desg FWD 4 128.30 P2p
Gi1/0/32 Desg FWD 4 128.32 P2p
Gi1/0/33 Desg FWD 4 128.33 P2p
Gi1/0/34 Desg FWD 4 128.34 P2p
Gi1/0/35 Desg FWD 4 128.35 P2p
Gi1/0/37 Desg FWD 4 128.37 P2p
Gi1/0/38 Desg FWD 4 128.38 P2p
Gi1/0/39 Desg FWD 4 128.39 P2p
Gi1/0/41 Desg FWD 4 128.41 P2p
Gi1/0/43 Desg FWD 4 128.43 P2p
Gi1/0/45 Desg FWD 4 128.45 P2p
Gi1/0/46 Desg FWD 4 128.46 P2p
Gi1/0/47 Desg FWD 4 128.47 P2p
Gi1/0/48 Desg FWD 4 128.48 P2p
Po1 Desg FWD 3 128.2377 P2p

please go through it .

[Giuseppe Larosa]

Hello surjinp07@ ,

I have asked for the output of :

show spanning-tree vlan 1 detail

only adding the detail keyword allows to understand if there are frequent recalculations

From what I see both switches are not the root bridge for VLAN 1 and one of them is more near cost 2 to the root bridge then the other one.

Where the port-channel 1 are connected to on both devices ?

Hope to help

Giuseppe

[surjinp07@]

hi

kindly please find the attachment. you can see the spanning tree vlan 1 details. and port channel have 2links 1/1/1 and 1/1/4 . these port channel connected between core switch and  core stanby switch . 

[Giuseppe Larosa]

Hello surjinp07@ ,

now I see the following:

CLILWORTH-DOWNSTAIRS-CORE# show spanning-tree vlan 1 detail

VLAN0001 is executing the rstp compatible Spanning Tree protocol
Bridge Identifier has priority 0, sysid 1, address b838.613a.6180
Configured hello time 2, max age 20, forward delay 15, transmit hold-count 6
>>>>>> We are the root of the spanning tree
Topology change flag not set, detected flag not set
>>> Number of topology changes 1108 last change occurred 05:45:28 ago
from Port-channel1

CHILWORTH-UPSTAIRS-CORE# show spanning-tree vlan 1 detail

VLAN0001 is executing the rstp compatible Spanning Tree protocol
Bridge Identifier has priority 8192, sysid 1, address 0c68.0345.1b80
Configured hello time 2, max age 20, forward delay 15, transmit hold-count 6
Current root has priority 1, address b838.613a.6180
>>>>> Root port is 2027 (Port-channel1), cost of root path is 3
Topology change flag not set, detected flag not set
Number of topology changes 331 last change occurred 05:42:58 ago

It is clear who is the root bridge the downstairs core and both agree on root bridge identity.

There is a quite number of Topology changes.

Rapid PVST requires that you configure spanning-tree port-fast on each end user access port to make the protocol efficient when recalculating (otherwise it can become even worse then traditional STP)

>> Also ports in spanning-tree portfast do not cause topoogy changes when they change state.

So I would suggest to check if all access ports are configured for spanning-tree port-fast or spanning-tree type edge.

Also trunk ports to APs can be configured this way even if a warning appears.

Note: this suggestion applies also to access layer switches all access ports in all switches should be portfast enabled

This is the next step in troubleshooting

Hope to help

Giuseppe

[surjinp07@]

hi Giuseppe,

as per your advice i did the configuration changes .i add spanning tree port fast on  the ports .i check all switches almost every ports already in spanning tree portfast mode. Still macflap happening in regular interval especially in the standby switch located upstairs core.

[Giuseppe Larosa]

Hello surjinp07@ ,

>> Still macflap happening in regular interval especially in the standby switch located upstairs core.

what is the frequency of this MAC flap events one time per hour or more ?

The frequency of these events can help in understand the issue.

For WIFI users a change of association to another AP creates a MAC flap event if the APs are working in bridge mode.

Edit:

I have reviewed your initial post in this thread . It is possible to understand if any cable has been added to the gateway ? I wonder if it is creating a bridging loop.

Have you cabled the unused port before configuring it ?

Likely there is an error in cabling if the messages are very frequent.

Hope to help

Giuseppe

[surjinp07@]

core switch upstair having more macflaps that is a standby . It showing 16 macflaps in an hours. core switch downstair  having 5 to 10 mac flaps every day.  I joined the organization last month only so i do not know how they did the cabling during configuration . 2 cable is going to firewall unifi pro 4 anyway

[Georg Pauwen]

Hello,

do you have a network topology diagram showing the physical connections ? 

[surjinp07@]

Hi 

 is there any update . i am waiting for your reply .still mac flap is there