Cisco 2960 switch ports flapping - Urgent

[senthilgm2000]

*Apr  3 05:56:08.795: %LINK-3-UPDOWN: Interface FastEthernet0/27, changed state

to down

*Apr  3 05:56:11.488: %LINK-3-UPDOWN: Interface FastEthernet0/27, changed state

to up

*Apr  3 05:56:12.495: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/27, changed state to up

*Apr  3 05:56:31.377: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/35, changed state to down

*Apr  3 05:56:32.384: %LINK-3-UPDOWN: Interface FastEthernet0/35, changed state

to down

*Apr  3 05:56:35.303: %LINK-3-UPDOWN: Interface FastEthernet0/35, changed state

to up

*Apr  3 05:56:36.310: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/35, changed state to up

*Apr  3 05:57:20.954: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/18, changed state to down

*Apr  3 05:57:21.952: %LINK-3-UPDOWN: Interface FastEthernet0/18, changed state

to down

*Apr  3 05:57:25.031: %LINK-3-UPDOWN: Interface FastEthernet0/18, changed state

to up

*Apr  3 05:57:26.037: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/18, changed state to up

*Apr  3 05:59:23.352: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/7, changed state to down

*Apr  3 05:59:24.350: %LINK-3-UPDOWN: Interface FastEthernet0/7, changed state t

o down

*Apr  3 05:59:31.909: %LINK-3-UPDOWN: Interface FastEthernet0/7, changed state t

o up

*Apr  3 05:59:35.230: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/7, changed state to up

*Apr  3 06:03:39.037: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/46, changed state to down

*Apr  3 06:03:40.035: %LINK-3-UPDOWN: Interface FastEthernet0/46, changed state

to down

*Apr  3 06:03:42.988: %LINK-3-UPDOWN: Interface FastEthernet0/46, changed state

to up

*Apr  3 06:03:43.995: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/46, changed state to up

*Apr  3 05:56:08.795: %LINK-3-UPDOWN: Interface FastEthernet0/27, changed state

to down

*Apr  3 05:56:11.488: %LINK-3-UPDOWN: Interface FastEthernet0/27, changed state

to up

*Apr  3 05:56:12.495: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/27, changed state to up

*Apr  3 05:56:31.377: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/35, changed state to down

*Apr  3 05:56:32.384: %LINK-3-UPDOWN: Interface FastEthernet0/35, changed state

to down

*Apr  3 05:56:35.303: %LINK-3-UPDOWN: Interface FastEthernet0/35, changed state

to up

*Apr  3 05:56:36.310: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/35, changed state to up

*Apr  3 05:57:20.954: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/18, changed state to down

*Apr  3 05:57:21.952: %LINK-3-UPDOWN: Interface FastEthernet0/18, changed state

to down

*Apr  3 05:57:25.031: %LINK-3-UPDOWN: Interface FastEthernet0/18, changed state

to up

*Apr  3 05:57:26.037: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/18, changed state to up

*Apr  3 05:59:23.352: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/7, changed state to down

*Apr  3 05:59:24.350: %LINK-3-UPDOWN: Interface FastEthernet0/7, changed state t

o down

*Apr  3 05:59:31.909: %LINK-3-UPDOWN: Interface FastEthernet0/7, changed state t

o up

*Apr  3 05:59:35.230: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/7, changed state to up

*Apr  3 06:03:39.037: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/46, changed state to down

*Apr  3 06:03:40.035: %LINK-3-UPDOWN: Interface FastEthernet0/46, changed state

to down

*Apr  3 06:03:42.988: %LINK-3-UPDOWN: Interface FastEthernet0/46, changed state

to up

*Apr  3 06:03:43.995: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/46, changed state to up

[Dejan Puhar · Accepted solution]

Hi,

can you put show interface of one of the flapping ports?

cheers

Dejan

[senthilgm2000]

FastEthernet0/46 is up, line protocol is up (connected)

  Hardware is Fast Ethernet, address is 64a0.e79a.4e2e (bia 64a0.e79a.4e2e)

  Description: GABORONE-LAN

  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation ARPA, loopback not set

  Keepalive set (10 sec)

  Full-duplex, 100Mb/s, media type is 10/100BaseTX

  input flow-control is off, output flow-control is unsupported

  ARP type: ARPA, ARP Timeout 04:00:00

  Last input never, output 00:00:01, output hang never

  Last clearing of "show interface" counters never

  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

  Queueing strategy: fifo

  Output queue: 0/0 (size/max)

  5 minute input rate 0 bits/sec, 0 packets/sec

  5 minute output rate 2000 bits/sec, 5 packets/sec

     2730924 packets input, 1241363631 bytes, 0 no buffer

     Received 378394 broadcasts (23743 multicasts)

     0 runts, 0 giants, 0 throttles

     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

     0 watchdog, 23743 multicast, 0 pause input

     0 input packets with dribble condition detected

     15327101 packets output, 2495115743 bytes, 0 underruns

     0 output errors, 0 collisions, 1 interface resets

     0 babbles, 0 late collision, 0 deferred

     0 lost carrier, 0 no carrier, 0 PAUSE output

     0 output buffer failures, 0 output buffers swapped out

FastEthernet0/46 is up, line protocol is up (connected)

  Hardware is Fast Ethernet, address is 64a0.e79a.4e2e (bia 64a0.e79a.4e2e)

  Description: GABORONE-LAN

  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation ARPA, loopback not set

  Keepalive set (10 sec)

  Full-duplex, 100Mb/s, media type is 10/100BaseTX

  input flow-control is off, output flow-control is unsupported

  ARP type: ARPA, ARP Timeout 04:00:00

  Last input never, output 00:00:01, output hang never

  Last clearing of "show interface" counters never

  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

  Queueing strategy: fifo

  Output queue: 0/0 (size/max)

  5 minute input rate 0 bits/sec, 0 packets/sec

  5 minute output rate 2000 bits/sec, 5 packets/sec

     2730924 packets input, 1241363631 bytes, 0 no buffer

     Received 378394 broadcasts (23743 multicasts)

     0 runts, 0 giants, 0 throttles

     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

     0 watchdog, 23743 multicast, 0 pause input

     0 input packets with dribble condition detected

     15327101 packets output, 2495115743 bytes, 0 underruns

     0 output errors, 0 collisions, 1 interface resets

     0 babbles, 0 late collision, 0 deferred

     0 lost carrier, 0 no carrier, 0 PAUSE output

     0 output buffer failures, 0 output buffers swapped out

[Dejan Puhar]

This looks clean, except

  Last input never,

So it seems that he is not receiving anything on this port, you can monitor it for few min to make sure there are no packets.

Do you have some ports on this one that are fine? If yes can you try to move connection from the flapping one to that one and see if the fault is following the interface or cable.

Also what is your speed/duplex configuration here? Maybe you can try fixing it to see if that is going to help.

Dejan

[senthilgm2000]

HI Dejan,

Its not happening for only one port,many ports are fluctuating like the same.

now fa0/4 has gone down.

*Apr  3 06:03:43.995: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthe

et0/46, changed state to up

*Apr  3 06:49:31.297: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthe

et0/4, changed state to down

*Apr  3 06:49:32.295: %LINK-3-UPDOWN: Interface FastEthernet0/4, changed state

o down

BW-UTi-GABORONE-SWC01#         sh int fa0/4

FastEthernet0/4 is down, line protocol is down (notconnect)

  Hardware is Fast Ethernet, address is 64a0.e79a.4e04 (bia 64a0.e79a.4e04)

  Description: GABORONE-LAN

  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation ARPA, loopback not set

  Keepalive set (10 sec)

  Auto-duplex, Auto-speed, media type is 10/100BaseTX

  input flow-control is off, output flow-control is unsupported

  ARP type: ARPA, ARP Timeout 04:00:00

  Last input never, output 00:43:36, output hang never

  Last clearing of "show interface" counters never

  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

  Queueing strategy: fifo

  Output queue: 0/0 (size/max)

  5 minute input rate 0 bits/sec, 0 packets/sec

  5 minute output rate 0 bits/sec, 0 packets/sec

     7235487 packets input, 1593375789 bytes, 0 no buffer

     Received 53729 broadcasts (888 multicasts)

     0 runts, 0 giants, 0 throttles

     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

     0 watchdog, 888 multicast, 0 pause input

     0 input packets with dribble condition detected

     18948686 packets output, 7423061327 bytes, 0 underruns

     0 output errors, 0 collisions, 1 interface resets

     0 babbles, 0 late collision, 0 deferred

     0 lost carrier, 0 no carrier, 0 PAUSE output

     0 output buffer failures, 0 output buffers swapped out

*Apr  3 06:03:43.995: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthe

et0/46, changed state to up

*Apr  3 06:49:31.297: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthe

et0/4, changed state to down

*Apr  3 06:49:32.295: %LINK-3-UPDOWN: Interface FastEthernet0/4, changed state

o down

BW-UTi-GABORONE-SWC01#         sh int fa0/4

FastEthernet0/4 is down, line protocol is down (notconnect)

  Hardware is Fast Ethernet, address is 64a0.e79a.4e04 (bia 64a0.e79a.4e04)

  Description: GABORONE-LAN

  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation ARPA, loopback not set

  Keepalive set (10 sec)

  Auto-duplex, Auto-speed, media type is 10/100BaseTX

  input flow-control is off, output flow-control is unsupported

  ARP type: ARPA, ARP Timeout 04:00:00

  Last input never, output 00:43:36, output hang never

  Last clearing of "show interface" counters never

  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

  Queueing strategy: fifo

  Output queue: 0/0 (size/max)

  5 minute input rate 0 bits/sec, 0 packets/sec

  5 minute output rate 0 bits/sec, 0 packets/sec

     7235487 packets input, 1593375789 bytes, 0 no buffer

     Received 53729 broadcasts (888 multicasts)

     0 runts, 0 giants, 0 throttles

     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

     0 watchdog, 888 multicast, 0 pause input

     0 input packets with dribble condition detected

     18948686 packets output, 7423061327 bytes, 0 underruns

     0 output errors, 0 collisions, 1 interface resets

     0 babbles, 0 late collision, 0 deferred

     0 lost carrier, 0 no carrier, 0 PAUSE output

     0 output buffer failures, 0 output buffers swapped out

[senthilgm2000]

*Apr  3 07:45:17.991: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/23, changed state to down

*Apr  3 07:45:19.996: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern

et0/23, changed state to up

*Apr  3 07:45:17.991: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern
et0/23, changed state to down
*Apr  3 07:45:19.996: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthern
et0/23, changed state to up

[matthewhenshaw]

Did you find a resolution to this problem?

[Dejan Puhar]

Hi Senthil,

I can see that you have many ports flapping, but do you have some that are working just fine? Is there anything in common for the flapping ports? Type of devices connected? Can you try to move one of the flapping devices to another switch to see if it will continue to flap, this is the fastest way to check who is going crazy.

If there is absolutelly nothing in common for the flaping ports/devices then it has to be switch misbehaving. Check cablings, patch pannel, devices...

But manipulating the cables from one device to another is the fastest way to move here.

so if you have host A connected to port A and flapping

and host B connected to port B and not flapping

just try to switch the ports for these 2 hosts and see what happens.

Let me know how it goes

Dejan

[senthilgm2000]

Thanks Dejan

will do and let you know

[Dejan Puhar]

Hi Senthil,

also just in case check the CPU, memory on the switch itslef to see if there is something wrong there.

Dejan

[senthilgm2000]

HI Dejan,

Just to confirm with the switch is running ios 12.2 version, advice me will it be cause any way around

[Dejan Puhar]

Put here the show ver to get all details

[ernie_2015]

Hi dejan 

Did this issue been closed/ resolved the problem?

i have the same problem but i am using Nexus 3k which is connected to a server.

[Leo Laohoo]

Right, this is a 2960 right?  With two dual-personality ports?

For this exercise, may I request you move whatever is on ports Fa0/46 to either Gi0/1 or Gi0/2.  We're going to do some TDR testing.   If you have fibre optic in either the port you are using, can I ask if we temporarily disconnect it?  This test won't take more than 10 seconds.

Here's the preliminary configurations:

conf t

interface Gi 0/1 (or Gi 0/2)

media rj

end

1.  Command:  test cable tdr interface Gi 0/1 (or Gi 0/2);

2.  wait for 5 to 7 seconds;

3.  Command:  sh cable tdr interface Gi 0/1 (or Gi 0/2);

4.  Post the output

Remove the cable from either Gi 0/1 or Gi 0/2 and return to Fa 0/46.  Undo the temporary changes to the SFP ports using the commands:

conf t

interface Gi 0/1 (or Gi 0/2)

media auto

end

We await for your result. 

[ebarticel]

Just to add something to discussion...

Did you add a switch to the topology?

Eugen