cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
655
Views
8
Helpful
5
Replies

Management domain length in VTP

chandra_rc16
Level 4
Level 4

Hi,

I'm preparing for my CCNA. Please don't mind if this is too small question to ask here.

What does the Management Domain length contains in a VTP packet?

Here is the screenshot from a cisco doc for understanding VTP.

management domain length.PNG

Regards,

Chandu              

Regards, Chandu
1 Accepted Solution

Accepted Solutions

Chandu,

1. Can we find out how many switches are there in the vtp domain including server, client & tansp?

There is no automatic tool for this. VTP protocol itself has no provisions to enumerate the count of switches in a VTP domain and their roles.

2. How to find the count of client switches & transp switches?

Not possible with VTP tools. You could of course visit the configuration of each switch and check its VTP settings but this option is probably not what you are asking for.

And finally is there any use to include the length of the domain name?

Because the IOS needs to know how many bytes in the "Management domain name" field are significant. If you were writing a software to process VTP packets, you would be able to read the entire "Management domain name" field as a 32-byte long string into memory easily, but you still need to know how long is the VTP domain name in that string.

Best regards,

Peter

View solution in original post

5 Replies 5

Peter Paluch
Cisco Employee
Cisco Employee

Hi Chandu,

The "Management domain length" is an unfortunate field designation. In reality, this field says what is the length of the VTP domain name.

In VTP packet header, the field for VTP domain name - the "Management domain name" has a constant length of 32 bytes. However, the true length of the VTP domain name can be anywhere between 1 and 32 characters, so the packet also carries information about how long the name is, exactly in the "Management domain length" field. If your VTP domain name is, say, "CCNA" then only 4 bytes out of 32 are occupied in the domain name field, and the "Management domain length" would carry the value of 4.

Best regards,

Peter

Sandeep Choudhary
VIP Alumni
VIP Alumni

HI Chandu,

Management domain Length: Used to specify the length of the VTP management domain or Indicates the size of the name that follows

The main purpose of VTP is to provide a facility by which individual Cisco switches can be managed as a group for VLAN configuration purposes. A VTP management domain is simply a group of switches that participate in sharing VTP information. A given switch can be part of only one VTP management domain at a time, and is part of no VTP management domain by default.

Regards

Dont forget to rate helpful posts.

chandra_rc16
Level 4
Level 4

Thanks to you both.

I've two more questions:

1. Can we find out how many switches are there in the vtp domain including server, client & tansp?

2. How to find the count of client switches & transp switches?

Is there any way?

Thanks in advance.

Regards,

Chandu

Regards, Chandu

And finally is there any use to include the length of the domain name?

Regards,

Chnadu

Regards, Chandu

Chandu,

1. Can we find out how many switches are there in the vtp domain including server, client & tansp?

There is no automatic tool for this. VTP protocol itself has no provisions to enumerate the count of switches in a VTP domain and their roles.

2. How to find the count of client switches & transp switches?

Not possible with VTP tools. You could of course visit the configuration of each switch and check its VTP settings but this option is probably not what you are asking for.

And finally is there any use to include the length of the domain name?

Because the IOS needs to know how many bytes in the "Management domain name" field are significant. If you were writing a software to process VTP packets, you would be able to read the entire "Management domain name" field as a 32-byte long string into memory easily, but you still need to know how long is the VTP domain name in that string.

Best regards,

Peter

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Innovations in Cisco Full Stack Observability - A new webinar from Cisco