WS-C3560-8PC: MGT vlan goes down

sudip.acharya1 · ‎10-25-2012

Hi

I have a 3560-8PC in which the mgt vlan randomly (twice in one day or 2 weeks later) goes into the down state and will return w/o any interventaion 15-20 minutes later. Int G0/1 is the uplink to a 3750. I dont think its a layer1 issue at this time since i have seen it work just fine for over 2 weeks and drop again. I don't see any errors on the 3750 either.

Any thoughts appreciated. Thanks.

WS-C3560-8PC 15.0(2)SE C3560-IPBASEK9-M

LOG:

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.Oct 20 19:34:37.533 EDT: %LINK-3-UPDOWN: Interface GigabitEthernet0/1, changeds tate to up

.Oct 20 19:34:38.590 EDT: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan20 , changed state to up

.Oct 20 19:34:39.546 EDT: %LINEPROTO-5-UPDOWN: Line protocol on Interface Gigabi tEthernet0/1, changed state to up

.Oct 20 19:34:45.527 EDT: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan20 , changed state to down

.Oct 20 19:34:46.500 EDT: %LINEPROTO-5-UPDOWN: Line protocol on Interface Gigabi tEthernet0/1, changed state to down

.Oct 20 19:34:47.507 EDT: %LINK-3-UPDOWN: Interface GigabitEthernet0/1, changed state to down

.Oct 20 19:35:24.258 EDT: %LINK-3-UPDOWN: Interface GigabitEthernet0/1, changed state to up

.Oct 20 19:35:25.357 EDT: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan20 changed state to up

.Oct 20 19:35:26.271 EDT: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/1, changed state to up

SwitchName#sh int vl 20

Vlan20 is up, line protocol is up

Hardware is EtherSVI, address is 6c9c.edaa.e0c1 (bia 6c9c.edaa.e0c1)

Internet address is 172.21.47.20/17

MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,

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

Encapsulation ARPA, loopback not set

Keepalive not supported

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

Last input 00:00:00, output 00:00:00, 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: 0/40 (size/max)

5 minute input rate 2000 bits/sec, 3 packets/sec

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

7476765 packets input, 551439923 bytes, 0 no buffer

Received 0 broadcasts (0 IP multicasts)

0 runts, 0 giants, 0 throttles

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

226276 packets output, 27794183 bytes, 0 underruns

0 output errors, 2 interface resets

0 unknown protocol drops

0 output buffer failures, 0 output buffers swapped out

glen.grant · ‎10-25-2012

You need to look at the L2 connecting port for any errors. You are just looking at the L3 SVI which won't tell you anything for actual L2 port errors. Look at the actual uplink on both sides for any link errors.

sudip.acharya1 · ‎10-25-2012

Still dont see anything sitck out from either of the outputs.

3560-8pc:

GigabitEthernet0/1 is up, line protocol is up (connected)

5 minute input rate 81000 bits/sec, 46 packets/sec

5 minute output rate 4000 bits/sec, 4 packets/sec

135265533 packets input, 43537186577 bytes, 0 no buffer

Received 101541308 broadcasts (64799987 multicasts)

0 runts, 0 giants, 0 throttles

57 input errors, 25 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog, 64799987 multicast, 0 pause input

0 input packets with dribble condition detected

3750:

T1-IDF47-W#sh int g2/0/3

GigabitEthernet2/0/3 is up, line protocol is up (connected)

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

5 minute output rate 67000 bits/sec, 59 packets/sec

17394548 packets input, 6508502537 bytes, 0 no buffer

Received 213697 broadcasts (163949 multicasts)

0 runts, 0 giants, 0 throttles

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

0 watchdog, 163949 multicast, 0 pause input

0 input packets with dribble condition detected

147527710 packets output, 46332821623 bytes, 0 underruns

0 output errors, 0 collisions, 1 interface resets

0 unknown protocol drops

Leo Laohoo · ‎10-25-2012

Your last output is not going to help.

Please post the COMPLETE output to the "sh interface" commands and don't edit it. You've just taken out the "juicy" bits.

sunny.choudary · ‎10-25-2012

The Vlan which the SVI is for would require atleat an active port for its line protocol be come up. Assuming,

GigabitEthernet0/1 is the only access or trunk port for vlan 20 and when this went down so does the SVI associated with it.

nisagar · ‎10-25-2012

Please check in the event of vlan UP/DOWN

#show mac add dyn vlan 20

Do you see any dynamically learned entries there ?

Regards

Nitin