Solved: Re: SW_MATM-4-MACFLAP_NOTIF - Page 2

frede_frede · ‎06-12-2012

Hi

I have a big problem with Vlan flapping, this is my topology

Switch 1 and Switch 2 have the SVI and HSRP configured. Switch 1 is the root bridge for all Vlans. The message vlan X is flapping between port Gi1/0/2 and port Po2 appears on Switch 3. The Po2 is connected to Switch 1.

The port settings in Sw3:

spanning-tree mode pvst

spanning-tree extend system-id

spanning-tree vlan 1-4094 priority 12288

interface Port-channel1

description "Sw2"

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 10,11,12,13

switchport mode trunk

switchport nonegotiate

spanning-tree vlan 1-4094 cost 6

!

interface Port-channel2

description "Sw1"

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 10,11,12,13

switchport mode trunk

switchport nonegotiate

interface GigabitEthernet1/0/21

description "Sw2"

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 10,11,12,13

switchport mode trunk

switchport nonegotiate

channel-group 1 mode passive

!

interface GigabitEthernet1/0/22

description "Sw2"

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 10,11,12,13

switchport mode trunk

switchport nonegotiate

channel-group 1 mode passive

!

interface GigabitEthernet1/0/23

description "Sw1"

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 10,11,12,13

switchport mode trunk

switchport nonegotiate

channel-group 2 mode passive

!

interface GigabitEthernet1/0/24

description "Sw1"

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 10,11,12,13

switchport mode trunk

switchport nonegotiate

channel-group 2 mode passive

In switch 1 and 2 settings are the same except the mode of the channel-group which is active.

I think the problem with "vlan X is flapping" is on the doors of servers that have more than one nic connected to the switch, a misconfiguration can cause the message "Vlan X is flapping Between port Gi1/0/2and port Po2 " and others messages, I say this because this message only appears in configured ports of two VLANs and not in the other two.

Is there any way to prevent such events, even if the problem is the servers?

Thank you for your help

frede_frede · ‎06-17-2012

Hi Vivek,

Today the MAC flap error happened again:

2012-06-17 12:10:58 SW_MATM-4-MACFLAP_NOTIF Host 0030.13e5.34f1 in vlan 10 is flapping between port Gi1/0/20 and port Po2

2012-06-17 12:10:57 SW_MATM-4-MACFLAP_NOTIF Host 0015.1728.420a in vlan 11 is flapping between port Gi1/0/14 and port Po2

2012-06-17 12:10:57 SW_MATM-4-MACFLAP_NOTIF Host 0015.1728.420c in vlan 11 is flapping between port Gi1/0/13 and port Po2

2012-06-17 12:10:57 SW_MATM-4-MACFLAP_NOTIF Host 0030.13e5.34f2 in vlan 10 is flapping between port Gi1/0/17 and port Po2

2012-06-17 12:10:57 SW_MATM-4-MACFLAP_NOTIF Host 0030.13e5.34f3 in vlan 10 is flapping between port Gi1/0/19 and port Po2

2012-06-17 12:10:57 SW_MATM-4-MACFLAP_NOTIF Host 0030.13e5.34f0 in vlan 10 is flapping between port Gi1/0/18 and port Po2

2012-06-17 12:10:43 SW_MATM-4-MACFLAP_NOTIF Host 0030.13e5.34f0 in vlan 10 is flapping between port Gi1/0/18 and port Po2

and unfortunately there was no change in topology ...

VLAN0010 is executing the ieee compatible Spanning Tree protocol

Bridge Identifier has priority 12288, sysid 10, address 0025.b4c0.c580

Configured hello time 2, max age 20, forward delay 15

Current root has priority 4163, address 0025.b4d8.6580

Root port is 520 (Port-channel2), cost of root path is 3

Topology change flag not set, detected flag not set

Number of topology changes 4 last change occurred 1w2d ago

from Port-channel2

Times: hold 1, topology change 35, notification 2

hello 2, max age 20, forward delay 15

Timers: hello 0, topology change 0, notification 0, aging 300

the problem must be in the side of the servers, if I use LACP to the server will solve the problem

Regards

Fred

frede_frede · ‎06-17-2012

I think I saw the problem

the problem is in the SW1 Po3

VLAN0010 is executing the ieee compatible Spanning Tree protocol

Bridge Identifier has priority 4096, sysid 10, address 0025.b4d8.6580

Configured hello time 2, max age 20, forward delay 15

We are the root of the spanning tree

Topology change flag not set, detected flag not set

Number of topology changes 42 last change occurred 10:28:39 ago

from Port-channel3

Times: hold 1, topology change 35, notification 2

hello 2, max age 20, forward delay 15

Timers: hello 0, topology change 0, notification 0, aging 300

The SW2 has no changes.

I never had problems in the connecting to this switch blade, but I think the problem is in Pe5, the Po can stay in FWD and cause the loop. I unfortunately do not make management of blades, but I have to take a look.

Regards

Fred

Vivek Ganapathi · ‎06-17-2012

Hi Fred,

Which VLAN do you use for data & management traffic? Looks to me like the impact is just to the management segment?

Vivek.

frede_frede · ‎06-18-2012

Hi Vivek,

I use the VLAN 100 for management, but this Vlan is not passing in Po3. The Vlans 10 and 11 with the mac flap problem, are the only ones in common between Po1 and Po3.

Regards

Fred

MUHAMMAD AZAM AMEER · ‎06-18-2012

hey

i have and issue connecting two routers with a 2960 switch which is connected to the internet switch?

can you give me an EXAMPLE OF ANY CONFIGURATION TO CONNECT THE ROUTERS, THE ROUTERS ARE 3945 ROUTERS PLEASE

Help

frede_frede · ‎07-04-2012

Hi Vivek,

I Have managed to overcome the problem

I configured in Po4 a port-priority and I don't have any more problems

thanks for the help

Regards

Fred