VTP not creating VLANs altough devices are shown

[aseques01]

I am having trouble trying to setup VTP on a already configured cisco 2960S. To improve the network consisteny I am trying to configure it as a VTP client for VTP3.

I followed the guide at cisco docs to troubleshooting and found that the usual cuplrits are:

• Different passwords on VTP
• Communication problems on the interfaces seen by the switches

In my case I think that none of those are issues, also I can do on the 2960s a show vtp devices and I get a proper list of devices

# sh vtp devices 
Retrieving information from the VTP domain. Waiting for 5 seconds.

VTP Feature Conf Revision Primary Server Device ID Device Description 
------------ ---- -------- -------------- -------------- ----------------------
VLAN   Yes       56 4001.7ad3.cfc0 0c85.258e.1254      SW11 
VLAN   Yes       56 4001.7ad3.cfc0 2852.61e7.1254      SW12 
VLAN   Yes       56 4001.7ad3.cfc0=4001.7ad3.1254      SW00 
VLAN   Yes       56 4001.7ad3.cfc0 64ae.0c75.1254      SW14

Enabling debug with these commands doesn't show any useful information about errors or anything remarcable

debug sw-vlan vtp packets 
debug sw-vlan vtp events 

Any ideas? I am quite lost and I tried all the tricks (setting to transparent then back to client, renaming VLANs trigger VTP, etc)..

[MHM Cisco World]

can we see 
show vtp status ?

[balaji.bandi]

from same device can yuo post show vtp status | in primary - if that matches information with this mac - then that is server

4001.7ad3.cfc0

You can only add or detele vlan in VTP Server to propogate other clients. as suggested good to have show run and show vtp status.

[aseques01]

Hi, I'm posting both switches vtp status output, on the server everything looks normal (in fact is propagating VLANs to the other switches without issue), but on the client the primary id it's always 0000.0000.0000.

On the server

#sh vtp status 
VTP Version capable : 1 to 3
VTP version running : 3
VTP Domain Name : DOMAIN
VTP Pruning Mode : Disabled
VTP Traps Generation : Disabled
Device ID : 4001.7ad3.cfc0

Feature VLAN:
--------------
VTP Operating Mode : Primary Server
Number of existing VLANs : 32
Number of existing extended VLANs : 0
Maximum VLANs supported locally : 4094
Configuration Revision : 56
Primary ID : 4001.7ad3.cfc0
Primary Description : SW00
MD5 digest : ......
......


Feature MST:
--------------
VTP Operating Mode : Transparent

On the one not receving the updates:

# sh vtp status 
VTP Version capable : 1 to 3
VTP version running : 3
VTP Domain Name : DOMAIN
VTP Pruning Mode : Disabled
VTP Traps Generation : Disabled
Device ID : 6c9c.ed8b.2c80

Feature VLAN:
--------------
VTP Operating Mode : Client
Number of existing VLANs : 19
Number of existing extended VLANs : 0
Maximum VLANs supported locally : 1005
Configuration Revision : 0
Primary ID : 0000.0000.0000
Primary Description : 
MD5 digest :


Feature MST:
--------------
VTP Operating Mode : Transparent


Feature UNKNOWN:
--------------
VTP Operating Mode : Transparent

[MHM Cisco World]

Vtp need trunk between switch are you use trunk ?

[Georg Pauwen]

Hello,

your output is showing that your client switch is not really running VTP version 3:

--> Maximum VLANs supported locally : 1005

This should be:

--> Maximum VLANs supported locally : 4096

A couple of things could be going on. Check if there is a 'vlan.dat' file in flash, and if so, delete that file (delete flash:vlan.dat). Also, make sure your switch is running the minimum IOS version required for VTP version 3, which is 12.2(52)SE.

[MHM Cisco World]

I run lab tonight and I get same result as your in case of link not config as trunk. 
so I read all your post again and see that you mention you use port-channel, 
I think the port member is config as trunk but the port-channel config as access 
how can we check ?
show interface <port member> switchport

show interface <port-channel> swithcport 

check the mode is trunk. 
share output if you can.
good luck friend 

[chike2much]

Hi,

Primary Server looks good .... Make sure the trunks links are set up correctly to other switches and can ping each in order to replicate VLANS on other switches real time.  Set other switches to client mode NOT transparent mode (because VLAN updates go tru the transparent switch but does not save or update its VLAN database) then start creating VLANS from the primary server(master switch) make sure domain name stays the same all the switches ... it should work. Cheers !!!

~Chike

[aseques01]

Hi @Georg Pauwen it definetely looks promising.

I just removed the vlan.dat file, but it doesn't seem to change anything, I tried changing to Transparent and back to client but doesn't change anything. It seems by reading other posts that I need to reload the switch aftewards so it can create a new file with proper data, is that right? I so, I will have to schedule a downtime window to make the changes.
Forgot to add the version, I'm on 15.2(2)E6 that's relatively recent and should support the feature nicely.

@chike2muchI already have a proper connection with the switches because I can see the neighbor devices.

[MHM Cisco World]

@chike2muchI already have a proper connection with the switches because I can see the neighbor devices.

the VTP protocol not work if the link is access you need to make it Trunk 

[Georg Pauwen]

Hello,

after removing the vlan.dat file, did you re-enter 'vtp version 3' ? I don't think you need a reload...

[aseques01]

Yes, it makes no difference:

#delete flash:vlan.dat 
Delete filename [vlan.dat]?  
Delete flash:/vlan.dat? [confirm]
#dir flash:/vlan.dat   
%Error opening flash:/vlan.dat (No such file or directory)

Then trying to trigger vlan.dat clean restore

#vtp version 3 
VTP version is already in V3.
dir flash:/vlan.dat 
%Error opening flash:/vlan.dat (No such file or directory)

Trying also changing from Client to Off and back to client made no difference

#sh vtp status  | include Max 
Maximum VLANs supported locally   : 1005

@MHM Cisco World  I am using a portchannel in trunk mode with all vlan allowed (also no restriction un portchannel members vlan list)

[MHM Cisco World]

only do this in SW which will be server Of VTP 
vtp primary vlan 

NOTE:- ABOVE is for new VTP config PLEASE BE CAREFULL. if you have Q ask before apply any command. THANKS

[aseques01]

HI  @MHM Cisco World  I recall doing this at some point where other switches didn't replicate the VLANs from the one I wanted because they had an old configuration. I don't think that this is the issue in this case because if the master was another switch instead of Primary ID : being zeros it would be another switch ID.

[Georg Pauwen]

Hello,

the switch still is not running version 3:

--> #sh vtp status | include Max
Maximum VLANs supported locally : 1005

Try and set it to version 1 or 2, then back to 3:

2960S#conf t
2960#(config)#no vtp version 3
2960#(config)#vtp version 1
2960S(config)#end
2960S#conf t
2960#(config)#vtp version 3
2960S(config)#end