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Beginner

Internet flapping.

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???

7 REPLIES 7
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Hall of Fame Community Legend

Re: Internet flapping.


@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.  

Beginner

Re: Internet flapping.

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

VIP Mentor

Re: Internet flapping.

Hello,

 

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

 

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

Beginner

Re: Internet flapping.

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
VIP Advisor

Re: Internet flapping.

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.

Beginner

Re: Internet flapping.

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

Re: Internet flapping.

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



kind regards
Paul

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