VTP v2 and v3

[Nabarun Halder]

What is difference between VTP v2 and VTP v3 ?

[InayathUlla Sharieff · Accepted solution]

Hi NAbarun,

Please find the details below:

VTP Details: -

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

-->  The main differences  between VTP Ver 3 and VTP Ver 2, the VTPv3 is able to distribute information about extended range VLANs, private VLANs, provides protection against unwanted overwriting of the VLAN database by a switch with a higher revision number, and is even able to synchronize MSTP region configuration throughout your VTP domain.

-->  The VTP password can be, to my best knowledge, encrypted only for VTPv3 using the command vtp password password hidden in the global configuration mode. After entering this command, the password will be stored in an encrypted format in the vlan.dat file and even the show vtp password command will be unable to reveal the original p

2-

VTP v2

VTP v2 is not much different than VTP V1. The major difference is that VTP V2 introduces support for Token Ring VLANs. If you use Token Ring VLANs, you must enable VTP V2. Otherwise, there is no reason to use VTP V2. Changing the VTP version from 1 to 2 will not cause a switch to reload.

In VTP version 2, if a switch is in transparent mode, it will forward the message without checking version information.  A transparent switch using VTP version 1 will check the domain and version before if forwards the frame.

VTP v3

•Support for extended VLANs (4094).

•Support for the creation and advertising of private VLANs.

•Support for VLAN instances and MST mapping propagation instances.

•Adds a new mode called "primary server" which is the only one allowed to make changes to the domain.

•Improved server authentication. VTP version 2 stored the password as ASCII in the running config. V3 stores it a hex number.

•Protection from the "wrong" database accidentally being inserted into a VTP domain.

•Interaction with VTP version 1 and VTP version 2.

•Ability to be configured on a per-port basis.

HTH

REgards

Inayath

*Plz rate te usefull posts.

[Ricardo Munioz Cabero]

Hello,

It is said that v3 is backward compatible with v2 and v1, so what would happen if we had one v3 primary server and a v2 server in the same domain.
- If we make a change in the v2 server, this would publish the change to all the other switches, including the clients and other v2 servers, but also to the v3 primary server.

- What would the v3 primary server do in this case? Learn or discard the advertisement.

Thanks.

[Ricardo Munioz Cabero]

Just found out:

- VTPv3 primary server will generate v3 advertisements and v2 advertisements (if it detects a v2 neighbor).

- However v3 devices are not able to accept v2 advertisements in its database, so v2 devices should be used only as clients, if not transparent.

[abhdivak]

Hello Inayath,

Which VTP version is enabled on cisco catalyst switches by default ?

Thanks,

Abhijith

[Joseph W. Doherty]

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Posting

I think v1 is the default.