Changing VTP domain Name

bapatsubodh · ‎02-22-2010

Hi,

If one switch has one VTP domain name configured with VTP mode as client. Then without reloading the switch another trunk is formed with another segment of the network. Then if we cahnge the VTP domain name to the new segment VTP domain name and VTP mode is still client.

In this case will this switch get the new VLAN information from the new VTP server switch or "configuration revision" number of server switch and cleint switch may create some problems. As if something goes wrong it can bring the whole LAN to standstill

Please share the experience.

Thanks

Subodh

KARUPPUCHAMY MALAIYANDI · ‎02-22-2010

Hi,

in VTP server client architecture, the vtp domain should be same in both server mode switch as well as client mode switch.

if the client switch vtp domain name is different than the vtp server mode switch, then this client will not get vlan update from the server switch.

// Then if we cahnge the VTP domain name to the new segment VTP domain name and VTP mode is still client. In this case will this switch get the new VLAN information from the new VTP server switch //

the above scenario, the client switch will not get vlan updates, so there wil be a huge impact.

thanks & regards

karuppu

bapatsubodh · ‎02-22-2010

Hi
KARUPPUCHAMY MALAIYANDI
I think I could not put my difficulty clearly,
Here is the deal, one USER_ swicth is connected to one segment via trunk having VTP domain name "Office" . Therse exists another segment
with VTP domain name as "Branch" to which switch is not connected.

Step 1:
USER_Swicth configured as client to VTP domain name "Office" this switch is connected to this this segment by a trunk.
USER_Switch is getting all VLAN updates from VTP server with domain as "Office" so far so good.

Step 2:
A new trunk is configured and working ok on USER_Switch which connects to the second segment that is having VTP domain name as "Branch"
Up to this step, User_Switch will not get any information from "Branch" VTP domain. As USER_Switch is currently client of "Office" domain.

Step 3:
Without reloading the USER_Switch we change the VTP domain name on the USER_Switch to "Branch" from it's original VTP domain name "Office".
USER_Swicth is a client to new VTP domain name.

At this point USER_Switch ( client ) has VTP domain name as "Branch" and also there exists a VTP server with the same domain name.
In this case ideally, USER_Switch should get all VLAN information from new VTP domain server namely "Branch".

But if we not reloading the switch and "revision" number of old VTP is higher than the current "revision number" of the new VTP domain what is the effect.

1. Will the client reset the revision number of old VTP domain and accept the new VTP update from new VTP server
2. Client switch will not accept any VTP updates from new VTP domain.
3. Something else will take place.
I hope I have made the scenario clear.
Please share the experience
Subodh

Jon Marshall · ‎02-22-2010

Subodh

You need to be really careful with this. A VTP client can still send out VTP advertisements. If it has a higher revision number than the VTP server for VTP domain Branch then the VTP client will overwrite the VTP servers vlan database and all the other switches in that VTP domain as well.

So if you change the VTP domain make sure that the revision number on the client is lower than the revision number on the VTP server for Branch VTP domain.

Jon

bapatsubodh · ‎02-22-2010

Hi,

Oh !!

If that is possible that client revision number is higher that server revision number, that will be create havoc.

It's better to reload the switch so that revision number will be reset to zero.

Is there any way to mannully reset the revision number to zero?

Thanks a lot for sharing the infromation.

subodh

Jon Marshall · ‎02-22-2010

bapatsubodh wrote:

Hi,

Oh !!

If that is possible that client revision number is higher that server revision number, that will be create havoc.

It's better to reload the switch so that revision number will be reset to zero.

Is there any way to mannully reset the revision number to zero?

Thanks a lot for sharing the infromation.

subodh

Subodh

Yes, you can reset the revision to number to zero by changing the switch to VTP transparent then changing it back to VTP client mode.

Jon