Flapping VLAN in c 2960X switch

[rsthakur]

We receive such log in 2960 X switch. Find attach switch configuration and image version.

.Feb 8 15:35:10: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to down
.Feb 8 15:35:10: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:35:11: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to up
.Feb 8 15:35:11: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:35:12: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to down
.Feb 8 15:35:12: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:35:13: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:35:14: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to up
.Feb 8 15:35:14: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to down
.Feb 8 15:35:14: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:35:16: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to up
.Feb 8 15:35:19: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to down
.Feb 8 15:35:20: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to up
.Feb 8 15:35:21: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to down
.Feb 8 15:35:22: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to up
.Feb 8 15:35:30: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:35:30: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:35:32: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:35:32: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to down
.Feb 8 15:35:32: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to up
.Feb 8 15:35:32: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:35:37: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to down
.Feb 8 15:35:38: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to up
.Feb 8 15:35:39: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to down
.Feb 8 15:35:41: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to up
.Feb 8 15:35:42: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to down
.Feb 8 15:35:43: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to up
.Feb 8 15:35:44: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to down
.Feb 8 15:35:45: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to up
.Feb 8 15:35:59: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to down
.Feb 8 15:36:00: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to up
.Feb 8 15:36:09: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:36:09: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to down
.Feb 8 15:36:09: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to up
.Feb 8 15:36:09: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:36:13: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:36:13: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to down
.Feb 8 15:36:13: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:36:14: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to up
.Feb 8 15:36:16: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to down
.Feb 8 15:36:17: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan5, changed state to up

[Leo Laohoo]

vlan.dat file is corrupt.

[rsthakur]

kindly elaborate this, and how to repair that.

[balaji.bandi]

try this steps :

https://www.cisco.com/c/en/us/support/docs/switches/catalyst-2940-series-switches/109304-manage-vlandat.html

[rsthakur]

Request you to join the party again. I didn't find any solution till now.

[Scott Leport]

@Leo Laohoo that's a good point!

@rsthakur, might be worth reconfiguring your 2960S again, e.g. deleting vlan.dat, erasing startup config and then re-apply configuration. 

[rsthakur]

@Leo Laohoo . @balaji.bandi . @Scott Leport . @pieterh 

I do every mention step very precisely. I have deleted vlan.dat on both x series and s series switch, erasing startup-config and then re-apply configuration on both switches. But still, I receive flapping and drop.

Please see attached new vlan.dat file for both switch

[balaji.bandi]

If you have done all as per the doc - next  step i chagne from VTP v1 to v2

[rsthakur]

How to change change from VTP v1 to v2.

[balaji.bandi]

make sure if this is big network do in maintenance window, this required to change all associated devices.

config t
!
vtp version 2
!
end

switch#show vtp status
VTP Version : 2

[rsthakur]

I changed vtp version but the problem still occurs. 

sh vtp status
VTP Version capable : 1 to 3
VTP version running : 2
VTP Domain Name : jst
VTP Pruning Mode : Disabled
VTP Traps Generation : Disabled
Device ID : 4c71.0c09.9a00
Configuration last modified by 172.28.64.60 at 2-10-21 14:25:19
Local updater ID is 172.28.64.60 on interface Vl19 (lowest numbered VLAN interface found)

Feature VLAN:
--------------
VTP Operating Mode : Server
Maximum VLANs supported locally : 1005
Number of existing VLANs : 67
Configuration Revision : 110
MD5 digest : 0x93 0x34 0xDD 0x00 0xB8 0x66 0xAA 0x27
0x8C 0xBD 0x95 0x7B 0xFB 0x3D 0xC8 0xF0

[balaji.bandi]

Looks like i have lost the track of the issue now - as per your old attachment i closly look, you have S Seriend and X Series - why both are VTP Server ? is this what you looking or intent to config.

can you post latest logs from the switch again. and clarify above also please.

post output

show run

show version

show vlan

[Scott Leport]

Kind of losing track of this one too. I think @pieterh might be onto something in regards to checking spanning-tree.

@rsthakurdo you have any topology diagrams of the environment you would be willing to share here?

Also worth mentioning, that it's not a good idea to have VTP servers configured everywhere as the risks associated with that are very well known! Best to run VTP client or VTP transparent mode on your edge switches, though appreciate that may not be the root cause here. 

[rsthakur]

Looks like i have lost the track of the issue now - as per your old attachment i closly look, you have S Seriend and X Series - why both are VTP Server ? is this what you looking or intent to config.

VTP work on server or client mode, I never seen at the time of fresh configuration. It picks automatically mode or version.

Recently i changed all 7 switch mode server to client but problem not slove.

Please find attach notepad for latest logs from the switch again.

[rsthakur]

doesn't matter if both switches are vtp servers they will update each other which ever makes a change unless version 3 is running.