VTP v3 primary ?

[paolo bevilacqua]

Can one set an IOS switch as VTP v3 primary database? Otherwise one can't configure VLANs in Server mode ?!?

[Edison Ortiz]

What platform are we talking about?

With the 6500, by default switches are configured as VTP v3 secondaries but this can be change with the CLI VTP Primary

More information can be found in the documentation:

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/vtp.html#wp1051097

If the question is not related to the 6500 platform, then my apologies.

[paolo bevilacqua]

A  2960 switch. There is no "primary" option for VTP commands.

[Peter Paluch · Accepted solution]

Hello Paolo,

VTPv3 is supported on 2960 switches starting with IOS version 12.2(52)SE. Version 3 has to be enabled explicitly on a switch using the vtp version 3 global configuration command - the version setting will not be inherited from other switches in the VTP domain automatically, contrary to VTPv1/VTPv2.

Setting a switch to be a VTP server (not a primary VTP server) is performed in global configuration mode using the vtp mode server command. This is a necessary prerequisite. Afterwards, if this switch should become a VTP primary server, the following command must be entered in the privileged EXEC mode (not in configuration mode):

vtp primary vlan

The vlan keyword can be omitted - it describes a so-called feature for which this switch is to become a primary VTP server (currently, two features are supported: VLAN and MST).

If this does not work please let us know, and also include the IOS version you are using. Optionally, the current VTP configuration and the transcript of the unsuccessful attempt to become the VTP primary server would also be helpful.

Best regards,

Peter

[paolo bevilacqua]

As mentioned above - there is no "vtp primary" option. Using latest IOS on  a WS-C2960-24PC-L.

BSL-SW-2(config)#vtp version 3

BSL-SW-2(config)#vtp mode server

Device mode already VTP Server for VLANS.

BSL-SW-2(config)#vtp ?

  domain     Set the name of the VTP administrative domain.

  file       Configure IFS filesystem file where VTP configuration is stored.

  interface  Configure interface as the preferred source for the VTP IP updater address.

  mode       Configure VTP device mode

  password   Set the password for the VTP administrative domain

  pruning    Set the administrative domain to permit pruning

  version    Set the administrative domain to VTP version

BSL-SW-2#

[Peter Paluch · Accepted solution]

Paolo,

Thank you. You have probably misread my previous reply: the vtp primary command is not accessible via configuration mode (because it is a runtime state, not a configuration setting) but rather simply in the privileged EXEC mode itself, i.e.:

Switch# vtp primary vlan

Can you please try this out? Thanks!

Best regards,

Peter

[paolo bevilacqua]

Works fine indeed... Thanks Peter!

[Peter Paluch]

Paolo,

I am glad it works. Thank you for the generous rating!

Best regards,

Peter

[xyf800212]

Thank you Peter, that solved my issue

[rozay1984]

Thanks Paolo,

all your information is very clear and valuable.

I'm glad when I found your replies.

A CCNP Student

[rudy.accardi]

Peter,

    Are there any caveats to performing the VTP Primary command while a 3850 stack live in production?

[Leo Laohoo]

It's not all the time to see Paolo get stumped at something! 

[hujatnoorie]

thanks it solved my problem.

[eAgencyInc]

See the highlighted Device ID and Name of THIS device and it is stated that THIS device is Primary. However, when I try to edit the VLAN config, I get an error saying it is NOT the Primary. So which is it?

sw2hq#show vtp status
VTP Version capable : 1 to 3
VTP version running : 3
VTP Domain Name : eahq
VTP Pruning Mode : Enabled
VTP Traps Generation : Disabled
Device ID : 0017.596c.af00

Feature VLAN:
--------------
VTP Operating Mode : Server
Number of existing VLANs : 9
Number of existing extended VLANs : 0
Maximum VLANs supported locally : 255
Configuration Revision : 6
Primary ID : 0017.596c.af00
Primary Description : sw2hq
MD5 digest : 0x70 0x6F 0x8A 0xC3 0x7E 0xFA 0x05 0xC3
0x49 0x3C 0x8D 0xCF 0x96 0xF3 0x66 0xFD

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

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

Error when attempting to edit the VLAN config:

sw2hq(config)#vlan 7
VTP VLAN configuration not allowed when device is not the primary server for vlan database.

I was going to make it the Primary as you described but I'm shown that it already IS the Primary. Could it be not?

EDIT:

Apparently, it could. Even though it said it already was Primary and other switches confirmed it, I made it Primary again and that worked, just as you described and others confirmed.