VTP v.1 Vs VTP v.2

[mohammedmahmoud]

All i am preparing for switching exam, and i've got a question regarding VTP:

Does a VTP v.1 trasparent switch forward VTP information(leanred from another server or client in the domain), and what is difference between v.1 and v.2 (other than TokenRing support and concistenct check)

Thanks in advance.

[nethelper]

Hello,

as for a transparent switch forwarding VTP advertisements: you need VTP version 2 for that.

For the differences between version 1 and version 2, check this link:

Understanding VTP Version 2

http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_guide_chapter09186a008007e709.html#wp1020429

There also is a VTP version 3, check this link for details:

Cisco VTP: VLAN Trunking Protocol

http://www.javvin.com/protocolVTP.html

Regards,

Nethelper

[pkhatri]

Hi,

In VTP V1, the only time a transparent mode switch will forward advertisements is when the version and domain name match (highly unlikely). In VTP v2, advertisements are forwarded regardless of the version number.

Here are the differences between v1 and v2 (from CCO):

VTP version 2 supports the following features, which are not supported in version 1:

* Token Ring support—VTP version 2 supports Token Ring LAN switching and VLANs (TrBRF and TrCRF).

* Unrecognized Type-Length-Value (TLV) Support—A VTP server or client propagates configuration changes to its other trunks, even for TLVs it is not able to parse. The unrecognized TLV is saved in NVRAM.

* Version-Dependent Transparent Mode—In VTP version 1, a VTP transparent network device inspects VTP messages for the domain name and version, and forwards a message only if the version and domain name match. Because only one domain is supported in the supervisor engine software, VTP version 2 forwards VTP messages in transparent mode, without checking the version.

* Consistency Checks—In VTP version 2, VLAN consistency checks (such as VLAN names and values) are performed only when you enter new information through the CLI or SNMP. Consistency checks are not performed when new information is obtained from a VTP message or when information is read from NVRAM. If the digest on a received VTP message is correct, its information is accepted without consistency checks.

Hope that helps - pls rate the post if it does.

Paresh

[mohammedmahmoud]

Thanks alot Paresh.

But there is still something missing, you said

"In VTP V1, the only time a transparent mode switch will forward advertisements is when the version and domain name match (highly unlikely). In VTP v2, advertisements are forwarded regardless of the version number."

My question is, why is it unlikely to have matched version and domain name in VTP v.1 case? (does version here means v.1 or v.2 or else ?)

My second question is, in VTP v.2 the version must not match, but the domain name must still match ?

Thanks in advance.

[pkhatri · Accepted solution]

My apologies.. that should have read "highly likely". What I mean is the VTP version number. As long as you configure the same VTP domain name for transparent mode switches (which people tend to do), the transparent mode switches will forward advertisements.

As to your second question, I'm pretty sure that version 2 has also dropped the requirement for matching domain names.

Paresh

[mohammedmahmoud]

Thanks alot Paresh, you were realy so helpfull.