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New Member

VTP Password Reset?

I'm adding a 3560G to my existing 3548-XL stack as a VTP client because I want it to get the VLAN config. After the basic config the switch is not getting VTP info from the server so I have three questions:

1. I have to connect the 3560 to my existing 3548 through the a switch port because the 3548 doesn't have SFP ports. Do I have to change the mode of the switch ports that are connecting the two switches to something special?

2. I added the 3560 to the VTP domain (hsf) but I'm not sure if there is a VTP password set which may be causing the issue. All these switches were in place when I cam on-board and I haven't had to mess with them much. SH VTP PASSWORD doesn't exist on the 3548 so I can't see what the password may be. Should I change the VTP password on all the existing switches so I know what it is? Will this hurt the existing VTP clients? Is there a better way to do this?

3. I'm I going about this wrong? Is there something else I need to change or configure to get it working?

1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Blue

Re: VTP Password Reset?

1) You need the port to be a trunk port. So you need to configure both ends as trunks.

2) Try 1 first before messing with the password.

What IOS version are you running on the 3548XL switches ?

Jon

8 REPLIES
Hall of Fame Super Blue

Re: VTP Password Reset?

1) You need the port to be a trunk port. So you need to configure both ends as trunks.

2) Try 1 first before messing with the password.

What IOS version are you running on the 3548XL switches ?

Jon

New Member

Re: VTP Password Reset?

I'm going to use port 48 on both switches to connect them.

On the 3548 I did SWITCHPORT MODE TRUNK and it worked fine.

When I did SWITCHPORT MODE TRUNK on the 3560 I got an error stating 'Command rejected: An interface whose trunk encapsulation is "Auto" can not be configured to "Trunk" mode.'

What do I need to make the encapsulation so it works? Is dot1q the only thing that will work on the 3548? Do I need to specify that on the 3548 and then on the 3560 before I can make it a trunk port?

All 3548s are running 12.0(5.1)XW

Hall of Fame Super Blue

Re: VTP Password Reset?

On the 3560

int fa0/48

switchport trunk encapsulatioin dot1q

switchport mode trunk

Jon

Hall of Fame Super Blue

Re: VTP Password Reset?

In addtion to previous post. I believe the 3548 defaults to ISL trunking so on the 3548

int fa0/48

switchport trunk encapsulation dot1q

switchport mode trunk

Jon

New Member

Re: VTP Password Reset?

You were correct about the default to ISL, thanks. The new 3560 is receiving VTP updates now and has all the correct VLAN info but now I can't reach the switch on the management VLAN IP. I can't ping from one switch to the other either.

Attached is my SH VLAN for clarification. VLAN 10 (HSF) is where all the ports on all the switches reside because we have a flat network currently.

Hall of Fame Super Blue

Re: VTP Password Reset?

Okay what is the management vlan for these switches - can you post output of "sh run" from the 3560 and the 3548.

Jon

New Member

Re: VTP Password Reset?

Sorry, it was my mistake. I had the LAN IP assigned to VLAN1 instead of VLAN10 which is what everything is using. Things seem to be working fine now. Thanks for the help.

New Member

Re: VTP Password Reset?

Hi,

1. you should configure the two ports as trunks in order to transmit different VLANs over them. I'm not sure but you should also set the Trunk encapsulation to the same value on both ends(e.g. dot1q).

2. Are there only 3548XL on the LAN. Otherwise you could enter "show vtp password" on another switch.

The only helpful action i could imagine is to debug vtp on the VTP server ("debug sw-vlan vtp packet"). Maybe this way you can see if the password entered is wrong.

Greets,

Sebastian

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