VTP issues

[rawiramdhan]

Could someone explain me this:

CSW-1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
CSW-1(config)#do sh vtp status
VTP Version capable : 1 to 3
VTP version running : 1
VTP Domain Name :
VTP Pruning Mode : Disabled
VTP Traps Generation : Disabled
Device ID : 0088.1b4f.b300
Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00
Local updater ID is 0.0.0.0 (no valid interface found)

Feature VLAN:
--------------
VTP Operating Mode : Server
Maximum VLANs supported locally : 1005
Number of existing VLANs : 5
Configuration Revision : 0
MD5 digest : 0x57 0xCD 0x40 0x65 0x63 0x59 0x47 0xBD
0x56 0x9D 0x4A 0x3E 0xA5 0x69 0x35 0xBC
CSW-1(config)#vtp domain SiteA
Changing VTP domain name from NULL to SiteA
CSW-1(config)#vtp v
*Jul 11 10:33:16.200: %SW_VLAN-6-VTP_DOMAIN_NAME_CHG: VTP domain name changed to SiteA.e
CSW-1(config)#vtp version 3
CSW-1(config)#
*Jul 11 10:33:18.292: %SW_VLAN-6-OLD_CONFIG_FILE_READ: Old version 2 VLAN configuration file detected and read OK. Version 3
files will be written in the future.
CSW-1(config)#vtp mode client
Setting device to VTP Client mode for VLANS.
CSW-1(config)#do sh vtp status
VTP Version capable : 1 to 3
VTP version running : 3
VTP Domain Name : SiteA
VTP Pruning Mode : Disabled
VTP Traps Generation : Disabled
Device ID : 0088.1b4f.b300

Feature VLAN:
--------------
VTP Operating Mode : Client
Number of existing VLANs : 5
Number of existing extended VLANs : 0
Maximum VLANs supported locally : 4096
Configuration Revision : 0
Primary ID : 0000.0000.0000
Primary Description :
MD5 digest :

Feature MST:
--------------
VTP Operating Mode : Transparent

Feature UNKNOWN:
--------------
VTP Operating Mode : Transparent

Without setting any password, only domain version en mode the MD5 changed. This is my VTP Server:

CSW-1(config)#do sh vtp status
VTP Version capable : 1 to 3
VTP version running : 3
VTP Domain Name : SiteA
VTP Pruning Mode : Disabled
VTP Traps Generation : Disabled
Device ID : 0088.1b4f.b300

Feature VLAN:
--------------
VTP Operating Mode : Client
Number of existing VLANs : 5
Number of existing extended VLANs : 0
Maximum VLANs supported locally : 4096
Configuration Revision : 0
Primary ID : 0000.0000.0000
Primary Description :
MD5 digest :

Feature MST:
--------------
VTP Operating Mode : Transparent

CSW-1#sh vtp password
The VTP password is not configured.
CSW-1#

This is on the client:

CSW-1#sh vtp status
VTP Version capable : 1 to 3
VTP version running : 3
VTP Domain Name : SiteA
VTP Pruning Mode : Disabled
VTP Traps Generation : Disabled
Device ID : 0088.1b4f.b300

Feature VLAN:
--------------
VTP Operating Mode : Client
Number of existing VLANs : 5
Number of existing extended VLANs : 0
Maximum VLANs supported locally : 4096
Configuration Revision : 0
Primary ID : 0000.0000.0000
Primary Description :
MD5 digest :

Feature MST:
--------------
VTP Operating Mode : Transparent

CSW-1#sh vtp password
The VTP password is not configured.

[Mark Malone]

Hi

changing the domain alters the md5 digest as its part of the calculation

https://cciepursuit.wordpress.com/2007/06/29/vtp-md5-hash-utilizes-vtp-domain-name/

[rawiramdhan]

But my domain names are the same? And one has a MD5 and one hasn't. 

[Julio E. Moisa]

Hi

It is because you are using different vtp versions, if you are going to configure vtp on the switches, all of them need to be configured with the same version, it is not replicated from the server to the clients or transparent devices. It is part of the vtp calculation.

Hope it is useful

:-)

[rawiramdhan]

They are both version 3:

DSW-1>sh vtp status
VTP Version capable : 1 to 3
VTP version running : 3
VTP Domain Name : SiteA
VTP Pruning Mode : Disabled
VTP Traps Generation : Disabled
Device ID : 0088.1b6a.ac00

Feature VLAN:
--------------
VTP Operating Mode : Server
Number of existing VLANs : 7
Number of existing extended VLANs : 0
Maximum VLANs supported locally : 4096
Configuration Revision : 2
Primary ID : 0088.1b6a.ac00
Primary Description : DSW-1
MD5 digest : 0x05 0x7F 0x68 0x3E 0xEF 0x79 0xE1 0x2A
0x8A 0x05 0x82 0xE2 0x65 0xAA 0x45 0x02

CSW-1>sh vtp status
VTP Version capable : 1 to 3
VTP version running : 3
VTP Domain Name : SiteA
VTP Pruning Mode : Disabled
VTP Traps Generation : Disabled
Device ID : 0088.1b4f.b300

Feature VLAN:
--------------
VTP Operating Mode : Client
Number of existing VLANs : 5
Number of existing extended VLANs : 0
Maximum VLANs supported locally : 4096
Configuration Revision : 0
Primary ID : 0000.0000.0000
Primary Description :
MD5 digest :

[Julio E. Moisa]

I see,

It is because this switch is not the VTP server yet, in order to complete the process to be the server, you need to configure vtp primary force:

Switch# vtp primary force

Once it is configured you will see the MD5 under the show vtp status. The way to configure VTP server from version 1 and 2 to 3 is different and from my point of view it is more robust and secure.

Hope it is useful

:-)

[rawiramdhan]

The client is missing the MD5. I can only configure vtp primary force when it is a server. Your comments are really appreciated!

[Julio E. Moisa]

If the server and client switches are properly configured to run vtp ver 3, the server must replicate the vlans and MD5 to the client. Please see the attachment.

Also you can verify if there are trunk interface between the server and client switches. The following command is optional, you could include it on the server:

SERVER#vtp primary vlan force
This system is becoming primary server for feature vlan

[paul driver]

Hello

The MD5 digest string seems to reset due to the promotion to vtp ver 3, I am assuming this is due to the re -synchronization of the vtp D/B to accommodate ver 3 hidden password feature..

SW4#sh vtp status
VTP Version capable             : 1 to 3
VTP version running             : 1
VTP Domain Name                 :
VTP Pruning Mode                : Disabled
VTP Traps Generation            : Disabled
Device ID                       : 0011.5c79.9500
Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00
Local updater ID is 0.0.0.0 (no valid interface found)

Feature VLAN:
--------------
VTP Operating Mode                : Server
Maximum VLANs supported locally   : 1005
Number of existing VLANs          : 5
Configuration Revision            : 0
MD5 digest                        : 0x57 0xCD 0x40 0x65 0x63 0x59 0x47 0xBD
                                    0x56 0x9D 0x4A 0x3E 0xA5 0x69 0x35 0xBC

SW4(config)#vtp domain SiteA
Changing VTP domain name from NULL to SiteA
SW4(config)#
*Mar  1 00:03:04.062: %SW_VLAN-6-VTP_DOMAIN_NAME_CHG: VTP domain name changed to SiteA.
SW4(config)#do sh vtp status
VTP Version capable             : 1 to 3
VTP version running             : 1
VTP Domain Name                 : SiteA
VTP Pruning Mode                : Disabled
VTP Traps Generation            : Disabled
Device ID                       : 0011.5c79.9500
Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00
Local updater ID is 0.0.0.0 (no valid interface found)

Feature VLAN:
--------------
VTP Operating Mode                : Server
Maximum VLANs supported locally   : 1005
Number of existing VLANs          : 5
Configuration Revision            : 0
MD5 digest                        : 0x36 0xFC 0xED 0x23 0x90 0x45 0x8A 0xFB
                                    0xD1 0x08 0x66 0x0E 0x04 0x37 0x2F 0xD2

SW4(config)#vtp ve 3
SW4(config)#
*Mar  1 00:03:31.980: %SW_VLAN-6-OLD_CONFIG_FILE_READ: Old version 2 VLAN configuration file detected and read OK.  Version 3
    files will be written in the future.
SW4(config)#do sh vtp status
VTP Version capable             : 1 to 3
VTP version running             : 3
VTP Domain Name                 : SiteA
VTP Pruning Mode                : Disabled
VTP Traps Generation            : Disabled
Device ID                       : 0011.5c79.9500

Feature VLAN:
--------------
VTP Operating Mode                : Server
Number of existing VLANs          : 5
Number of existing extended VLANs : 0
Configuration Revision            : 0
Primary ID                        : 0000.0000.0000
Primary Description               :
MD5 digest                        : 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
                                    0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00



res
Paul