From: Jason Madsen (madsen.jason@gmail.com)
Date: Sat Jan 03 2009 - 14:29:22 ARST
Another thing I just thought of is that by default STP (and other protocols)
are not allowed through q in q tunnels. I didn't see anything about them in
your email, but if you had one on your switch and didn't tunnel through STP
as well this could contribute to your issue.
Jason
On Sat, Jan 3, 2009 at 9:26 AM, Jason Madsen <madsen.jason@gmail.com> wrote:
> Hi Sajid,
>
> To me MAC Flapping indicates that a switch is "seeing" a MAC address flap
> between different ports. Typically with Layer 2 switches Spanning Tree runs
> and determines a loop-free path through our topology. With a stable network
> you should only see 1 MAC address coming from 1 port. The main reason I can
> think of continually seeing it in different places is because a loop is
> present in your network somewhere.
>
> Some potential causes could be having redundant paths in your network and
> having "spanning-tree disable", "bpdu-filter", or possibly "portfast"
> without bpduguard on one or more of your trunk links preventing
> Spanning-Tree from doing the necessary "blocks". It's difficult to say
> exactly what's happening on your switch without seeing config's though. I'd
> certainly take a look at your Fa0/7 and Po1 interface config's for
> starters.
>
> Jason
>
>
> On Sat, Jan 3, 2009 at 2:31 AM, sajid mavani <sajidmavani@gmail.com>wrote:
>
>> Hi Jason,
>>
>> Sorry for the late reply, I dont have a access to the switches as I was
>> doing a remote session online. As far as my knowledge goes I dont think
>> that bpdu-filter or spaning tree was disable.. I just had to do a layer 2
>> etherchanel between all the 4 switches .. as i enabled lacp on it .. I
>> started gettting that error message,
>>
>>
>> Kindly let me know in such cases if you get this kind of error messages,
>> what all trouuble shooting steps could be performed.
>>
>> Thanks everyone for your guidance and jason sorry once again for replying
>> late,
>>
>> Have a ncie day.
>>
>> Regards
>>
>> Sajid
>>
>> On Fri, Jan 2, 2009 at 7:55 PM, Jason Madsen <madsen.jason@gmail.com>wrote:
>>
>>> you don't have bpdu-filter or spanning-tree disable on any of your trunk
>>> links, do you?
>>>
>>>
>>>
>>>
>>> On Fri, Jan 2, 2009 at 7:17 AM, Jason Madsen <madsen.jason@gmail.com>wrote:
>>>
>>>> maybe you've created a spanning tree loop. do you have physical access
>>>> to the switch, or is a remote rack type situation?
>>>>
>>>>
>>>> On Thu, Jan 1, 2009 at 10:12 PM, sajid mavani <sajidmavani@gmail.com>wrote:
>>>>
>>>>> Hello Everyone,
>>>>>
>>>>>
>>>>> Please let me know what could I do to get this resolved..
>>>>>
>>>>>
>>>>> When I created a etherchanel between SW1 & SW2 .. I got the following
>>>>> error
>>>>> message listed below.. Please let me know how would i get this
>>>>> resolved, as
>>>>> I have got this similar type of messages on many occasions.
>>>>>
>>>>>
>>>>> {Configuration used
>>>>>
>>>>>
>>>>> SW1 & SW2
>>>>>
>>>>>
>>>>> conf t
>>>>>
>>>>>
>>>>> int range fas 0/19 - 20
>>>>>
>>>>> switchport trunk encapsulation dot1q
>>>>>
>>>>> switchport mode trunk
>>>>>
>>>>> chanel-group 1 mode active ( lacp) }
>>>>>
>>>>>
>>>>> Below is the error message i received.
>>>>>
>>>>> SW2#
>>>>>
>>>>> %SW_MATM-4-MACFLAP_NOTIF: Host *0030.8587.f331* in vlan 1 is flapping
>>>>> between port Fa0/7 and port Po1
>>>>>
>>>>> %SW_MATM-4-MACFLAP_NOTIF: Host 0030.8587.f331 in vlan 1 is flapping
>>>>> between
>>>>> port Fa0/7 and port Po1
>>>>>
>>>>> *
>>>>> *
>>>>>
>>>>> *####################################################################
>>>>> *
>>>>>
>>>>> *Trouble shooting the problem *
>>>>>
>>>>> * *
>>>>>
>>>>>
>>>>>
>>>>> *1) Below oput shows this for verification *
>>>>>
>>>>>
>>>>>
>>>>> SW2#sh mac address-table vlan 1
>>>>>
>>>>> Mac Address Table
>>>>>
>>>>> -------------------------------------------
>>>>>
>>>>>
>>>>>
>>>>> Vlan Mac Address Type Ports
>>>>>
>>>>> ---- ----------- -------- -----
>>>>>
>>>>>
>>>>>
>>>>> 1 001a.2fd4.3d17 DYNAMIC Po3
>>>>>
>>>>> *1 0030.8587.f331 DYNAMIC Po1*
>>>>>
>>>>> * 1 0030.8587.f332 DYNAMIC Po1*
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> 2)
>>>>>
>>>>> * *
>>>>>
>>>>> *SW3#sh mac address-table address 0030.8587.f331 *
>>>>>
>>>>> * Mac Address Table*
>>>>>
>>>>> *-------------------------------------------*
>>>>>
>>>>> * *
>>>>>
>>>>> *Vlan Mac Address Type Ports*
>>>>>
>>>>> *---- ----------- -------- -----*
>>>>>
>>>>> 1 *0030 .8587.f331* DYNAMIC Po1
>>>>>
>>>>> Total Mac Addresses for this criterion: 1
>>>>>
>>>>>
>>>>> 3)
>>>>>
>>>>>
>>>>>
>>>>> SW2#clear mac address-table dynamic interface port-channel 1 vlan 1
>>>>>
>>>>>
>>>>> SW2 #clear mac address-table dynamic interface port-channel 1 vlan 1
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> ............................................................................
>>>>>
>>>>>
>>>>>
>>>>> Still I am getting the same error message.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> I would be great full if anyone could let me know how to get this
>>>>> resolved.
>>>>>
>>>>>
>>>>>
>>>>> Regards
>>>>>
>>>>>
>>>>> Sajid
>>>>>
>>>>>
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>>>>>
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