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VLAN info not propagating over VTP trunks

7jgray
Level 1
Level 1

I have a Cisco 3550 with IOS version 12.1(22) and a Cisco 3560 with IOS version 12.2(25r). They are connected via the fa 0/48 port. Below is all the config info.

Switch 1

Switch_1>sho vtp status

VTP Version : 2

Configuration Revision : 1

Maximum VLANs supported locally : 1005

Number of existing VLANs : 11

VTP Operating Mode : Client

VTP Domain Name : Cisco

VTP Pruning Mode : Disabled

VTP V2 Mode : Disabled

VTP Traps Generation : Disabled

MD5 digest : 0xF9 0xF4 0x82 0xED 0xF4 0x66 0xA1 0xD1

Configuration last modified by 10.1.0.0 at 3-1-93 01:49:36

Switch_1>sho vtp counters

VTP statistics:

Summary advertisements received : 73

Subset advertisements received : 36

Request advertisements received : 6

Summary advertisements transmitted : 41

Subset advertisements transmitted : 11

Request advertisements transmitted : 34

Number of config revision errors : 5

Number of config digest errors : 33

Number of V1 summary errors : 0

Switch_1>sho int trunk

Port Mode Encapsulation Status Native vlan

Fa0/48 auto 802.1q trunking 1

Port Vlans allowed on trunk

Fa0/48 1-4094

Port Vlans allowed and active in management domain

Fa0/48 1,4,8,10,12,100,102

Port Vlans in spanning tree forwarding state and not pruned

Fa0/48 1,4,8,10,12,100,102

Switch 2

Switch_2#sho vtp status

VTP Version : 2

Configuration Revision : 3

Maximum VLANs supported locally : 1005

Number of existing VLANs : 7

VTP Operating Mode : Server

VTP Domain Name : Cisco

VTP Pruning Mode : Disabled

VTP V2 Mode : Disabled

VTP Traps Generation : Disabled

MD5 digest : 0x23 0x2C 0x0E 0x97 0xE9 0x11 0x53 0x66

Configuration last modified by 10.2.0.0 at 3-1-93 01:40:59

Local updater ID is 10.2.0.0 on interface Vl1 (lowest numbered VLAN interface fo

und)

Switch_2#sho vtp counters

VTP statistics:

Summary advertisements received : 26

Subset advertisements received : 3

Request advertisements received : 28

Summary advertisements transmitted : 57

Subset advertisements transmitted : 29

Request advertisements transmitted : 0

Number of config revision errors : 2

Number of config digest errors : 0

Number of V1 summary errors : 0

Switch_2#sho int trunk

Port Mode Encapsulation Status Native vlan

Fa0/48 on 802.1q trunking 1

Port Vlans allowed on trunk

Fa0/48 1-4094

Port Vlans allowed and active in management domain

Fa0/48 1,4,7

Port Vlans in spanning tree forwarding state and not pruned

Fa0/48 1,4,7

It appears they are trunking but no vlan info is getting updated. Any help would be greatly appreciated.

8 Replies 8

ankbhasi
Cisco Employee
Cisco Employee

Hi Friend,

There is a mismatch is VTP password configured on your 2 switches.

From the output on Switch 1:

Number of config digest errors : 33 <<<<---

This means that there is a mismatch in password. I will recommend you to reconfigure the VTP password on both the switches and see if that resolves the issue.

HTH

Ankur

*Pls rate all helpfull post

Amit Singh
Cisco Employee
Cisco Employee

Hello,

There is a VTP password mismatch on VTP cleint i.e switch1. Check this :

Switch_1>sho vtp counters

VTP statistics:

Summary advertisements received : 73

Subset advertisements received : 36

Request advertisements received : 6

Summary advertisements transmitted : 41

Subset advertisements transmitted : 11

Request advertisements transmitted : 34

Number of config revision errors : 5

Number of config digest errors : 33 <<<<<<-----

Number of V1 summary errors : 0

Config Digest errors means that you have a VTP password mismatch. Please make sure that you have the same password on VTP server and client and you will be good to go.

HTH,Please rate if it does.

-amit singh

I'm not using passwords.

Hi Friend,

VTP password is definetely configured on your switches.

Have a look at the output from your switch

MD5 digest : 0xF9 0xF4 0x82 0xED 0xF4 0x66 0xA1 0xD1 <<<<<-----

This means that password is configured.

HTH

Ankur

Ok, I may be in business. I'm learning all fo this for the BCMSN test and I bet I set a password when going over the commands.

Thanks for the help.......

That fixed it. Thanks for the help. One question. If I setup vlans on the client and the server, when the server propagates to the client it will delete all of the vlans that had previously been created on the switch.

Thanks,

jg

Hi Jg,

Yes, the VTP server will override the Vlan database on client switches.VLan information is not saved on NVARM on the VTP client switches.

Please rate all helpful posts.

-amit singh

Hi Friend,

You will not be able to setup vlans on client switch, you can only do on server switch or switches which are in transparent mode.

But yes whatever vlans you configure on your VTP server switch it will be synchronised on all client switches provided domain name and password are same.

Also in a situation when you connect new client switch which has higher config revision number on it as compared to your vtp server switch, in that case your VTP server switch will update itself with vlan information on your new client switch.

Hope I am able to explain.

Regards,

Ankur

*Pls rate all helpfull post

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