Meraki wireless APs and Mac flapping

ladams · ‎10-28-2013

I'm having some sporadic network issues (users sporadically losing network connectivity). I'm wondering if the problem is related to Mac flapping that has been occuring. Every floor's access switch (Catalyst 2960s) is connected to the core switches (Nexus 5K) via a vpc connection. I see several Mac flapping notifications throughout the day and I believe it is because my clients are roaming between access points. There is quite a lot of bleed over between floors and clients will roam between APs pretty easily. Here is a log from one of the access switches:

Log Buffer (4096 bytes):

8.624: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0012 in vlan 18 is flapping between port Gi1/0/23 and port Po1

023020: Oct 28 15:26:58.624: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0018 in vlan 24 is flapping between port Gi1/0/23 and port Po1

023021: Oct 28 15:26:58.624: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.001b in vlan 27 is flapping between port Gi1/0/23 and port Po1

023022: Oct 28 15:26:58.624: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.001d in vlan 29 is flapping between port Gi1/0/23 and port Po1

023023: Oct 28 15:26:58.624: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.001e in vlan 30 is flapping between port Gi1/0/23 and port Po1

023024: Oct 28 15:26:58.624: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0021 in vlan 33 is flapping between port Gi1/0/23 and port Po1

023025: Oct 28 15:26:58.634: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0001 in vlan 1 is flapping between port Gi1/0/23 and port Po1

023026: Oct 28 15:26:58.634: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0002 in vlan 2 is flapping between port Gi1/0/23 and port Po1

023027: Oct 28 15:26:58.634: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0016 in vlan 22 is flapping between port Gi1/0/23 and port Po1

023028: Oct 28 15:26:58.634: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0019 in vlan 25 is flapping between port Gi1/0/23 and port Po1

023029: Oct 28 15:26:59.116: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.001a in vlan 26 is flapping between port Gi1/0/23 and port Po1

023030: Oct 28 15:26:59.116: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.001c in vlan 28 is flapping between port Gi1/0/23 and port Po1

023031: Oct 28 15:26:59.116: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.001f in vlan 31 is flapping between port Gi1/0/23 and port Po1

023032: Oct 28 15:26:59.116: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0020 in vlan 32 is flapping between port Gi1/0/23 and port Po1

023033: Oct 28 15:26:59.116: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0029 in vlan 41 is flapping between port Gi1/0/23 and port Po1

023034: Oct 28 15:38:00.836: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0001 in vlan 1 is flapping between port Gi1/0/21 and port Po1

023035: Oct 28 15:38:00.836: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0002 in vlan 2 is flapping between port Gi1/0/21 and port Po1

023036: Oct 28 15:38:00.836: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0016 in vlan 22 is flapping between port Gi1/0/21 and port Po1

023037: Oct 28 15:38:00.836: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0019 in vlan 25 is flapping between port Gi1/0/21 and port Po1

023038: Oct 28 15:38:00.836: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.001a in vlan 26 is flapping between port Gi1/0/21 and port Po1

023039: Oct 28 15:38:00.836: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.001c in vlan 28 is flapping between port Gi1/0/21 and port Po1

023040: Oct 28 15:38:00.836: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.001f in vlan 31 is flapping between port Gi1/0/21 and port Po1

023041: Oct 28 15:38:00.841: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0020 in vlan 32 is flapping between port Gi1/0/21 and port Po1

023042: Oct 28 15:38:00.841: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0029 in vlan 41 is flapping between port Gi1/0/21 and port Po1

023043: Oct 28 15:38:00.841: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0000 in vlan 23 is flapping between port Gi1/0/21 and port Po1

023044: Oct 28 15:38:00.841: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0012 in vlan 18 is flapping between port Gi1/0/21 and port Po1

023045: Oct 28 15:38:00.847: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0018 in vlan 24 is flapping between port Gi1/0/21 and port Po1

023046: Oct 28 15:38:00.888: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.001b in vlan 27 is flapping between port Gi1/0/21 and port Po1

023047: Oct 28 15:38:00.888: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.001d in vlan 29 is flapping between port Gi1/0/21 and port Po1

023048: Oct 28 15:38:00.888: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.001e in vlan 30 is flapping between port Gi1/0/21 and port Po1

023049: Oct 28 15:38:00.894: %SW_MATM-4-MACFLAP_NOTIF: Host 0281.3c5d.0021 in vlan 33 is flapping between port Gi1/0/21 and port Po1

Here is the config of both interfaces:

IDF10#sh run int g1/0/21
Building configuration...

Current configuration : 95 bytes
!
interface GigabitEthernet1/0/21
switchport trunk native vlan 23
switchport mode trunk
end

IDF10#sh run int g1/0/23
Building configuration...

Current configuration : 95 bytes
!
interface GigabitEthernet1/0/23
switchport trunk native vlan 23
switchport mode trunk
end

Leo Laohoo · ‎10-28-2013

flapping between port Gi1/0/23 and port Po1

Your issue has got NOTHING to do with wireless. Error messages like this is commonly attributed to your uplink ports not properly configured for Etherchannel and your port configurations proves it.

ladams · ‎10-29-2013

How should the ports be configured? The APs themselves are on VLAN 23. The users are placed in a different VLAN based on the SSID that they connect to. Is there a document that I can review that references this?

devils_advocate · ‎10-29-2013

Presumably Gi1/0/21 and Gi1/0/23 should be part of Port Channel 1?

What is connected to Gi1/0/21 and 23? Access points?

ladams · ‎10-29-2013

Port Channel 1 is made up of two spf+ and is a vpc to the core switch. The Catalyst 2960s that is connected to po 1 has Meraki MR16s connected to Gi1/0/21 and 23. I don't understand why I would want to connect these to po 1.

!

interface Port-channel1

description Port-channel to Core

switchport mode trunk

load-interval 30

!

interface TenGigabitEthernet1/0/1

description Port-channel to Core

switchport mode trunk

channel-group 1 mode active

!

interface TenGigabitEthernet3/0/1

description Port-channel to Core

switchport mode trunk

channel-group 1 mode active

end

Leo Laohoo · ‎10-29-2013

Post the output to the command "sh etherchann 1 summary".

l33d5un1t3d · ‎10-29-2013

RE: "I don't understand why I would want to connect these to po 1." I don't understand either why?

Also i;ve seen the same messages at different customer sites with differet hardware that I can confirm are relaed to roaming wi-fi clients.........so I don't agree with Leo's comments either at this stage.

devils_advocate · ‎10-29-2013

Sounds to me like clients are roaming between access points which are physically connected to different access switches.

I am guessing these are autonomous access points and not controller based?

It could be normal in a wireless network where clients regularly roam.

l33d5un1t3d · ‎10-29-2013

"It could be normal in a wireless network where clients regularly roam" Based on experience I tend to agree.

ladams · ‎10-29-2013

IDF10#sh etherchann 1 summary
Flags: D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

Number of channel-groups in use: 6
Number of aggregators: 6

Group Port-channel Protocol Ports
------+-------------+-----------+-----------------------------------------------
1 Po1(SU) LACP Te1/0/1(P) Te3/0/1(P) Te4/0/1(D

Leo Laohoo · ‎10-29-2013

Draw your network.