what is the meaning of Error *** MD5 digest checksum mismatch on trunk: Fa0/19 ***

Hi Experts

I am doing VTP transparent advanced technology lab. I created vlan "123" on VTP Server mode which is SW2. Then, I was expecting to be able to see this newly created vlan "123" on SW3 which is the client mode. However, this did not happen. when I looked at SW3 and executed the command "Show vtp status" , the error message appeared like

*** MD5 digest checksum mismatch on trunk: Fa0/19 ***
*** MD5 digest checksum mismatch on trunk: Fa0/20 ***

I did not know that MD5 digest checksum is being used on the trunk link. I am using the regular Trunk encapsulation with Dot1q without using any password or any forms of the authentications. what can be the root cause of this problem happening like that. the output is pasted below for SW2 which is VTP server and SW3 which is VTP Client. Similar error poped up in SW2 which is VTP Server mode also:

*Mar  1 02:48:18.759: %SW_VLAN-4-VTP_USER_NOTIFICATION: VTP protocol user notification: MD5 digest checksum mismatch on receipt of equal revision summary on trunk: Fa0/23

SW2>
SW2>
SW2>enable
SW2#show vlan brief

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Fa0/1, Fa0/2, Fa0/3, Fa0/4
                                                Fa0/5, Fa0/6, Fa0/7, Fa0/8
                                                Fa0/9, Fa0/10, Fa0/11, Fa0/12
                                                Fa0/13, Fa0/14, Fa0/15, Fa0/16
                                                Fa0/17, Fa0/18, Fa0/19, Fa0/20
                                                Fa0/21, Fa0/22, Gi0/1, Gi0/2
123  VLAN0123                         active

....................................................................................................................

Following is the output from SW3 which is VTP Client mode. VLAN 123 was not advertised from VTP Server to thiis switch which is VTP Client:

SW3#show vlan brief

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Fa0/1, Fa0/2, Fa0/3, Fa0/4
                                                Fa0/5, Fa0/6, Fa0/7, Fa0/8
                                                Fa0/9, Fa0/10, Fa0/11, Fa0/12
                                                Fa0/13, Fa0/14, Fa0/15, Fa0/16
                                                Fa0/17, Fa0/18, Fa0/21, Fa0/22
                                                Fa0/23, Fa0/24, Gi0/1, Gi0/2
1002 fddi-default                     act/unsup
1003 trcrf-default                    act/unsup
1004 fddinet-default                  act/unsup
1005 trbrf-default                    act/unsup
SW3#show vtp status
VTP Version capable             : 1 to 3
VTP version running             : 2
VTP Domain Name                 : CCIE
VTP Pruning Mode                : Disabled
VTP Traps Generation            : Disabled
Device ID                       : 0019.5684.8700
Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00

Feature VLAN:
--------------
VTP Operating Mode                : Client
Maximum VLANs supported locally   : 1005
Number of existing VLANs          : 5
Configuration Revision            : 0
MD5 digest                        : 0xCB 0xAE 0xBC 0x17 0x1E 0x8D 0x7D 0xB7
                                    0x3D 0xA6 0xDD 0xF0 0xE5 0x89 0x64 0x94
*** MD5 digest checksum mismatch on trunk: Fa0/19 ***
*** MD5 digest checksum mismatch on trunk: Fa0/20 ***
SW3#
SW3#

Comments

  • It seems that I found the link to my question and It was helpful so I thought to share it and not taking anybody else's time. The link is below:

     

    https://supportforums.cisco.com/discussion/11923241/md5-digest-checksum-mismatch-trunk-gi01 

    I could fix the problem with creating a bogus vlan like vlan 999 on VTP server mode so that it made the switch in VTP server mode to advertise new VTP revison number of one to all other switches and they got synchronized. other wise, VTP versions were the same on the switches and there was no VTP Password set. but all of the switches including client, server and transparent switches revision number had stayed in revison numver zero without being updated. creating new vlan forced the update from VTP server mode to other switches.

    However, My question is that why did I end up creating new bogus vlan on VTP server to make the update happen from VTP servr to the client. why at the time of finishing the lab, the new vlans which were almost 17 new vlans did not get advertised from VTP server mode to VtP Client mode. IOS version is not the issue because it is 15 code.

    Thanks

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