Internet flapping.

[AnkitLal80888]

I have a C2960X-UNIVERSALK9-M connected to several XIrrus APs and directly connected to ISP for internet.

People are reporting Internet cut outs..2960, 

and i am seeing logs with 

%LINK-3-UPDOWN
%SW_MATM-4-MACFLAP_NOTIF
%IP-4-DUPADDR
%LINEPROTO-5-UPDOWN

for multiple ports.. 

Sep 4 03:19:55.461: %ILPOWER-5-POWER_GRANTED: Interface Gi1/0/14: Power granted
Sep 4 03:20:01.123: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/14, changed state to up
Sep 4 03:20:02.126: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/14, changed state to up
Sep 4 03:20:08.522: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/14, changed state to down
Sep 4 03:20:09.522: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/14, changed state to down
Sep 4 03:20:14.328: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/14, changed state to up
Sep 4 03:20:15.331: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/14, changed state to up
Sep 4 03:20:48.882: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/14, changed state to down
Sep 4 03:20:49.885: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/14, changed state to down
Sep 4 03:20:52.685: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/14, changed state to up
Sep 4 03:20:53.685: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/14, changed state to up
Sep 4 04:05:25.760: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/8, changed state to down
Sep 4 04:05:26.760: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/8, changed state to down
Sep 4 04:05:34.327: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/8, changed state to up
Sep 4 04:05:35.330: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/8, changed state to up
Sep 4 04:19:55.994: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/8, changed state to down
Sep 4 04:19:56.994: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/8, changed state to down
Sep 4 04:20:04.432: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/8, changed state to up
Sep 4 04:20:05.435: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/8, changed state to upSep 4 21:34:17.748: %IP-4-DUPADDR: Duplicate address 10.131.xxx.42 on Vlan1, sourced by cc44.633f.da97
Sep 4 21:38:40.888: %IP-4-DUPADDR: Duplicate address 10.131.xxx.42 on Vlan1, sourced by cc44.633f.da97
Sep 4 21:39:32.705: %IP-4-DUPADDR: Duplicate address 10.131.xxx.42 on Vlan1, sourced by cc44.633f.da97
Sep 5 05:07:52.809: %SW_MATM-4-MACFLAP_NOTIF: Host 64c7.53b2.0880 in vlan 1 is flapping between port Gi1/0/1 and port Gi1/0/14
Sep 5 05:15:22.005: %SW_MATM-4-MACFLAP_NOTIF: Host xxx.53b2.0880 in vlan 1 is flapping between port Gi1/0/14 and port Gi1/0/3
Sep 5 22:13:34.246: %IP-4-DUPADDR: Duplicate address 10.131.xxx.42 on Vlan1, sourced by 68ef.436c.ad78
Sep 8 21:48:37.059: %IP-4-DUPADDR: Duplicate address 10.131.xxx.42 on Vlan1, sourced by cc44.633f.da97
Sep 8 22:09:13.865: %IP-4-DUPADDR: Duplicate address 10.131.xxx.42 on Vlan1, sourced by cc44.633f.da97
Sep 9 01:14:28.707: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/9, changed state to down
Sep 9 01:14:30.710: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/9, changed state to up
Sep 9 01:22:54.383: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/2, changed state to down
Sep 9 01:22:56.389: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/2, changed state to up
Sep 9 01:36:17.155: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/9, changed state to down
Sep 9 01:36:19.158: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/9, changed state to up
Sep 9 21:48:17.777: %IP-4-DUPADDR: Duplicate address 10.131.xxx.42 on Vlan1, sourced by cc44.633f.da97
Sep 10 21:35:22.409: %IP-4-DUPADDR: Duplicate address 10.131.xxx.42 on Vlan1, sourced by cc44.633f.da97
Sep 10 22:27:47.141: %SW_MATM-4-MACFLAP_NOTIF: Host 64c7.53b2.0880 in vlan 1 is flapping between port Gi1/0/7 and port Gi1/0/26
Sep 11 02:54:44.076: %SW_MATM-4-MACFLAP_NOTIF: Host 64c7.53b2.0880 in vlan 1 is flapping between port Gi1/0/3 and port Gi1/0/4
Sep 11 04:11:42.752: %SW_MATM-4-MACFLAP_NOTIF: Host 64c7.53b2.0880 in vlan 1 is flapping between port Gi1/0/4 and port Gi1/0/3

Any ideas???

[Leo Laohoo]

---

@AnkitLal80888 wrote:

%SW_MATM-4-MACFLAP_NOTIF
%IP-4-DUPADDR

---

Frankly, I don't care about the link flapping, however, I am concerned about the two alarms.  

[AnkitLal80888]

ok what about them and how to get rid of them?

[Georg Pauwen]

Hello,

what devices are connected to ports Gi1/0/1, Gi1/0/2, Gi1/0/9 ?

Post the output of 'show cdp neighbors'...

[AnkitLal80888]

SAUG_Library#sh cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone,
D - Remote, C - CVTA, M - Two-port Mac Relay

Device ID Local Intrfce Holdtme Capability Platform Port ID
ceovkeir01c43.ims.telstra.com.au
Gig 1/0/16 141 R S I ISR4351/K Gig 0/0/2
XR503080008FB Gig 1/0/14 126 S Xirrus XR Gig1
XR402340E4AD3 Gig 1/0/26 147 S Xirrus XR Gig1/2
d0ec35430ca6 Gig 1/0/4 176 R S I SG250-10P gi10

[Seb Rupik]

Hi there,

The MAC flap is probably caused by wireless clients roaming between APs.

Where are clients getting their IP addresses from on VLAN1 ?

Are some clients statically assigned? Have you configured DHCP scope exceptions? 

It would probably be a good idea to configure DHCP snooping at the very least on the switches connected to your APs.

cheers,

Seb.

[AnkitLal80888]

IP allocations are stored on the DHCP server though - and are leased for (default) 7 days

[paul driver]

Hello

Two macs in your post (apple devices) are complaining about duplicate addressing, Any change these have statically defined ip addressing or are dishing out ip addresses??
cc44.63
68ef.43