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

[Giuseppe Larosa]

Hello @rsthakur ,

try to enable ip routing with

conf t

ip routing

ip route 0.0.0.0 0.0.0.0 172.28.71.254

or even better :

int vlan 5

shut

if it has no IP address you do not need it at all. (as a L3 SVI interface)

Hope to help

Giuseppe

[rsthakur]

i have 30 2960X switch but few switch showing such log.

i shut int vlan 5 and run

conf t

ip routing

ip route 0.0.0.0 0.0.0.0 172.28.71.254

these command  but still we receive such log.

.Feb 8 15:51:25: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:51:27: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:51:30: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:51:31: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:51:32: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:51:33: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:51:34: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:51:37: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:51:46: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:51:46: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:51:52: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:51:53: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:51:53: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:51:56: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:51:58: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:51:58: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:52:00: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:52:00: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:52:05: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:52:06: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:52:07: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:52:08: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:52:09: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:52:12: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:52:16: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:52:18: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:52:19: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:52:19: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:52:24: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:52:24: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:52:26: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:52:26: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:52:28: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:52:28: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:52:32: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:52:34: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up
.Feb 8 15:52:34: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to down
.Feb 8 15:52:35: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan19, changed state to up

[Leo Laohoo]

Ok, I know what is going on. 

VLAN 5 is the voice VLAN while VLAN 19 is the Data VLAN. 

One (or more) port(s) is going up/down.

Just to test, disable VLAN 5 and VLAN 19 and see which port(s) is flapping.  Remove their VLANs and enable VLANs 5 & 19 back.

[rsthakur]

no telephone and device is connected.

sh cdp n
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
Acad3_Test_28.64.61
Gig 1/0/23 131 S I WS-C2960X Gig 1/0/23

sh ip int brief
Interface IP-Address OK? Method Status Protocol
Vlan1 unassigned YES unset administratively down down
Vlan19 172.28.64.60 YES manual up up
FastEthernet0 unassigned YES unset administratively down down
GigabitEthernet1/0/1 unassigned YES unset down down
GigabitEthernet1/0/2 unassigned YES unset down down
GigabitEthernet1/0/3 unassigned YES unset down down
GigabitEthernet1/0/4 unassigned YES unset down down
GigabitEthernet1/0/5 unassigned YES unset down down
GigabitEthernet1/0/6 unassigned YES unset down down
GigabitEthernet1/0/7 unassigned YES unset down down
GigabitEthernet1/0/8 unassigned YES unset down down
GigabitEthernet1/0/9 unassigned YES unset down down
GigabitEthernet1/0/10 unassigned YES unset down down
GigabitEthernet1/0/11 unassigned YES unset down down
GigabitEthernet1/0/12 unassigned YES unset down down
GigabitEthernet1/0/13 unassigned YES unset down down
GigabitEthernet1/0/14 unassigned YES unset down down
GigabitEthernet1/0/15 unassigned YES unset down down
GigabitEthernet1/0/16 unassigned YES unset down down
GigabitEthernet1/0/17 unassigned YES unset down down
GigabitEthernet1/0/18 unassigned YES unset down down
GigabitEthernet1/0/19 unassigned YES unset down down
GigabitEthernet1/0/20 unassigned YES unset down down
GigabitEthernet1/0/21 unassigned YES unset down down
GigabitEthernet1/0/22 unassigned YES unset down down
GigabitEthernet1/0/23 unassigned YES unset up up
GigabitEthernet1/0/24 unassigned YES unset down down
GigabitEthernet1/0/25 unassigned YES unset down down
GigabitEthernet1/0/26 unassigned YES unset down down
Te1/0/1 unassigned YES unset down down
Te1/0/2 unassigned YES unset down down

[Leo Laohoo]

Ok, so nothing is connected? 

What is the output to the following command: 

sh post

[rsthakur]

sh post
Stored system POST messages:

Switch 1
---------

POST: MA BIST : Begin
POST: MA BIST : End, Status Passed

POST: TCAM BIST : Begin
POST: TCAM BIST : End, Status Passed

POST: Thermal, Fan Tests : Begin
POST: Thermal, Fan Tests : End, Status Passed

POST: PortASIC Stack Port Loopback Tests : Begin
POST: PortASIC Stack Port Loopback Tests : End, Status Passed

POST: PortASIC Port Loopback Tests : Begin
POST: PortASIC Port Loopback Tests : End, Status Passed

POST: EMAC Loopback Tests : Begin
POST: EMAC Loopback Tests : MAC Loopback Passed
POST: EMAC Loopback Tests : PHY Loopback Passed
POST: EMAC Loopback Tests : End, Status Passed

[balaji.bandi]

This is normal if no device connected to switch you see this information, you need to have 1 device active on the interface which belong to VLAN 5 and 19 for the VLAN interface come up.

post below output

show interface status

show ip interface brief

[rsthakur]

Ok i understand, but why only few switch give this error, other switch not show such log even it in ideal condition(no device connected).

Also when i connected any device to this switch then we receive drop on data and voice.

[Leo Laohoo]

Look at the config you've posted. 

VLAN 5 and VLAN 19 are not in the VLAN Database. 

conf t
 vlan 5
 vlan 19
end

This is why the interface VLANs are going up/down.  

[rsthakur]

I request you to see again above the attached text notepad file.

[Leo Laohoo]

---

@rsthakur wrote:

I request you to see again above the attached text notepad file.

---

VLAN interface is there but where is the VLAN database entries?  They are not there.

[rsthakur]

Vlan Database enties is avilable on BackBone 6807 switch.

interface Vlan17
description Academic-1 VLAN
ip address 172.28.55.254 255.255.248.0
ip helper-address 172.28.48.99
!
interface Vlan18
description Community Center VLAN
ip address 172.28.63.254 255.255.248.0
ip helper-address 172.28.56.99
!
interface Vlan19
description AB-3 VLAN
ip address 172.28.71.254 255.255.248.0
ip helper-address 172.28.64.99

sh ip int brief

Vlan5 172.xx.x.250 YES NVRAM up up
Vlan11 172.28.7.254 YES NVRAM up up
Vlan12 172.28.23.254 YES NVRAM up up
Vlan13 172.28.15.254 YES NVRAM up up
Vlan14 172.28.31.254 YES NVRAM up up
Vlan15 172.28.39.254 YES NVRAM up up
Vlan16 172.28.47.254 YES NVRAM up up
Vlan17 172.28.55.254 YES NVRAM up up
Vlan18 172.28.63.254 YES NVRAM up up
Vlan19 172.28.71.254 YES NVRAM up up
Vlan20 172.28.79.254 YES NVRAM up up
Vlan21 172.28.87.254 YES NVRAM up up
Vlan22 172.28.95.254 YES NVRAM up up
Vlan23 172.28.103.254 YES NVRAM up up

[Scott Leport]

Hi there,

I also noticed that the VLANs weren't present in the config file you supplied, but it should create the VLAN and add it to the VLAN database as a consequence of adding them to the switchports you have configured as access ports. Not how I would do it personally, but it works. If you look at the VLAN database by issuing a "show vlan brief" then it may appear as VLAN005, VLAN011 etc etc....

I am also in agreement that if you don't have anything live on this switch configured within these VLANs then they're going to show as down. A few questions if you don't mind:

1. Is it a new switch or existing?

2. Do you run VTP? If so, does your VTP config on this switch match up with others on this network?

3. What about the switch connected to port Gi0/23, is that doing any VLAN pruning or is it permitting all VLANs across the trunk?

[rsthakur]

If we connected any device on that switch then we didnot recieve any flapping, but we getting drop in data and voice and ping also.

1. Is it a new switch or existing?

Yes, this is a new switch, Before that 50 more switches connected in the same subnet but all are working fine. All switch configuration same only interface IP changed.

2. Do you run VTP? If so, does your VTP config on this switch match up with others on this network?

Not sure about that, we attach switch configuration kindly check.

3. What about the switch connected to port Gi0/23, is that doing any VLAN pruning or is it permitting all VLANs across the trunk?

No, switch connected to port Gi0/23 is working fine( we attach all confirmation and log). In that switch configuration same only interface IP is change.