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Community Member

Risk of changing to VTP version?

Hi,

I have a local 3750 that is giving me VTP warnings and filling up the logs.

165394: Sep 10 10:32:53.015 EDT: %SW_VLAN-4-VTP_USER_NOTIFICATION: VTP protocol user notification: Version 1 device detected on Gi2/0/24 after grace period has ended

The remote switch (info below) is still runing VTP 1. What is the risk/impact of setting the remote switch to 2?

 

This is the VTP info for the local switch.

VTP Version                     : running VTP2
Configuration Revision          : 83
Maximum VLANs supported locally : 1005
Number of existing VLANs        : 48
VTP Operating Mode              : Server
VTP Domain Name                 : Corpo
VTP Pruning Mode                : Enabled
VTP V2 Mode                     : Enabled
VTP Traps Generation            : Disabled
MD5 digest                      : 0x54 0x74 0x17 0xB2 0x40 0xDD 0x56 0x0B

 

Here is the Remote switch

VTP Version                     : running VTP1 (VTP2 capable)
Configuration Revision          : 20
Maximum VLANs supported locally : 1005
Number of existing VLANs        : 26
VTP Operating Mode              : Server
VTP Domain Name                 : Corpo
VTP Pruning Mode                : Disabled
VTP V2 Mode                     : Disabled
VTP Traps Generation            : Disabled
MD5 digest                      : 0x84 0x28 0x22 0xCA 0xB9 0xD9 0x32 0xE6

1 REPLY
Cisco Employee

Hi,If I look at the above VTP

Hi,

If I look at the above VTP information I see they both are not synchronized between eachother.

Question what happens/impact when you change the vtp version to 2.

I dont see any impact, were in if you configure with the same domain and password the remote switch would get sychnozed with the server with proper vlan information.

The major difference between VTP version 1 and version 2 are:
 
1.  Support for Token Ring Vlans.
 
2. Version 2 supports consistancy checks.  This means that when new information about the VTP domain is entered through the command line or some other method like SNMP, VTP version 2 will perform the consistancy check.  VTP version 2 will not check a VTP frame if is it received from another VTP peer or if the information is obtained from NVRAM.  The VTP peer will perfom a MD5 hash check on a VTP frame received from a VTP peer and if it's correct, it will accept the message.
 
3.  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.

Best practice would be:

NOTE: Change the Remote switch mode to Transparent, do all the required changes and made it to be client to avoid any issue.

 

HTH

Inayath

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