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VTP3 vs VTP2

bgorrell
Level 1
Level 1

I've downloaded and installed 12.2(33)SXI on a WS-SUP720-10G with the objective of migrating to VTP3 in order to turn off VTP on a per-trunk basis.

The rest of the network runs 12.2(33)SXH on WS-SUP720-3B using VTP2. In testing mode, these are standalone supervisors.

The documentation states that all devices in a VTP domain must run the same VTP version. In contradiction to this, there is also a section explaining the interaction between VTP V3 and V2 devices. (http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/vtp.html) I've set up VTP3 as the primary server, and configured a VTP domain and no password. On the switch running 12.2(33)SXH, I've configured it as a VTP client using V2 and configured the same VTP domain and no password. The client is not sending or receiving Configuration Revisions when a vlan is added to the domain throught the VTP 3 primary server. I set the vtp server to use VTP2, but the client is still not sending or receiving configuration revisions (the count is not incrementing.)

Any ideas?

16 Replies 16

Edison Ortiz
Hall of Fame
Hall of Fame

Please post the show vtp status and show int trunk output.

HTH,

__

Edison.

bgorrell
Level 1
Level 1

I added "vlan 3" to the vtp primary server hostname "vtp3".

Odd..

One thing I see is the VTP Client having 11 existing Vlans, how those Vlans were created? When the switch was configured as VTP transparent or server?

One way to fix this, delete the vlan.dat from flash and reload the switch. It will automatically receive the VTP information from the current VTP server via the trunk switchports. It will also set itself to VTP server so you will need to change it again to VTP client but at that point, all Vlans are migrated.

HTH,

__

Edison.

I'll try deleting the vlan.dat file. That's a good idea. My two issues are: can I have a vtp3 server in a vtp2 domain (which fails for me although the documentation states it is possible) and why isn't the config revision incrementing on the client when I turned vtp3 into a vtp2 server. Maybe deleting the vlan.dat file and restarting will fix this.

The 11 vlans were created when I configured device vtp2 from client to transparent modes. I was attempting to validate that I could still create vlans and that the conf revision number was not incrementing. I would then create a new vlan (ex vlan 3 in the posting) on the vtp server (vtp3) and then check device vtp2 to verify that the conf rev number had not incremented.

As you created the database originally in transparent mode, I wonder if the VTP server is unable to overwrite that file for some reason.

Please delete the vlan.dat as I suggested and post back with results.

HTH,

__

Edison.

Please rate helpful posts

The database was orginally created on device vtp3 using VTP version 3 in server mode. I was chaning device vtp2 from client to transparent mode to verify that the vlans could be created.

I deleted the vlan.dat file on both devices vtp2 and vtp3. I configured the vtp server for vtp version 2 on device vtp3 and added a vlan. Device vtp2 is in client mode running vtp version 2 and it will not receive a configuration revision update. I've include the config files of both devices.

You need a domain name to exchange VTP updates.

__

Edison.

Oops. Thanks. It looks like deleting the vlan.dat file was what I needed to do. The client is receiving configuration revision updates.

Do you know if VTP version 3 is compatible with VTP version 2? (I've contradictory information in the configu guide.) If so, what do I need to modify to force the vtp version 2 client to receive updates from the vtp version 3 server?

The VTP version 3 is backward compatible with VTP version 2.

Enabling VTP version 3 in a server will allow the server to use the new features that came with VTP version 3 on others VTPv3 enabled devices while communicating with VTPv2 devices in VTPv2 mode.

HTH,

__

Edison.

Please rate helpful posts

I can't get it to work. This is the issue that started this thread. Do you have a sample config?

No, I do not. I suggest you open a TAC Case and work with them on duplicating your scenario.

One thing to keep in mind, don't force the VTP Server to run in V3 mode only. It must be able to communicate in VTP mode 2 for those VTPv2 clients/servers.

__

Edison.

Leo Laohoo
Hall of Fame
Hall of Fame

"configured a VTP domain and NO password"

VTP Domain and VTP Password must be the same before VLAN database will propagate.

By the way: Good idea setting up the 2nd one as a client. :)

Aren't the passwords the same if no passwords are configured? In our current VTP2 environment we have only the VTP domain name configured. The VTP domain name is configured on both of these devices.

Leo Laohoo
Hall of Fame
Hall of Fame

You have NO VTP password.

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