CCNA3 Exploration Chapter 4. Study questions. Answers
4.1
What is the purpose of VTP?
To make the management of VLANs easier by allowing switches to learn
about VLANs from each other.
What sort of link between switches is needed to transmit VTP
advertisements?
A trunk link.
What are the three VTP modes that a switch could take?
Server, client and transparent.
What name is given to a group of switches that share VLAN information using
VTP?
A VTP domain.
Which VTP modes allow switches to save VLAN information in the vlan
database?
Server mode switches store VLAN information for their domain. Transparent
mode switches store information about their own VLANs.
Which VTP versions can be used on a Catalyst 2960 switch, and which is the
default version?
Versions 1 and 2 can be used. Version 1 is the default. There is a version 3
that can be used on some switches, but no on the Catalyst 2960.
How is a VTP domain identified?
By its domain name.
Which command is commonly used to display information about VTP?
Show vtp status
How is a VTP message encapsulated?
It is encapsulated inside an Ethernet frame that is tagged using 802.1Q or
ISL.
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What destination MAC address is used for VTP messages?
The multicast address 01-00-0C-CC-CC-CC
What does a server switch do to the configuration revision number when a
new VLAN is added?
Increases it by 1.
What is the purpose of including the configuration revision number in a VTP
advertisement?
It shows the receiving switch whether the advertisement contains more up to
date information than the information that it already has.
Which type of VTP advertisement contains information about VLANs?
The subset advertisement.
How often does a switch send out summary advertisements?
Every 5 minutes, or when the VLAN configuration is changed.
A client switch is reset. How does it obtain VLAN information?
It does not have any vlan database of its own, so it needs to obtain VLAN
information from a server switch in its domain. It sends out a VTP request
advertisement and receives information in a subset advertisement from the
server.
A client switch receives a summary advertisement with a lower configuration
revision number than its own. What does it do?
It will forward the summary advertisement to any other switches, but do
nothing else about it. There is no newer VLAN information available.
A client switch receives a summary advertisement with a higher configuration
revision number than its own. What does it do?
It sends out a VTP request advertisement and receives information in a
subset advertisement from the server.
A transparent switch receives a summary advertisement. What does it do?
It will forward the summary advertisement to other switches but ignore its
contents.
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Which modes of switch will allow you to create new VLANs?
Server switches (for the domain) and Transparent switches (for local use
only).
Is it possible to have more than one server switch on a domain?
Yes. It is a good idea to have more than one server. If there was only one
server and it failed, then the VLAN information would be lost.
Is a transparent switch able to obtain VLAN information when it reboots?
If the switch has any VLANs configured then they will be saved in the switch’s
own VLAN database, and they will be retrieved. The switch stays in
transparent mode (assuming that the configuration has been saved.)
Does any VLAN configuration have to be carried out on a client switch?
Switchports need to be assigned to VLANs. This is not done centrally, but is
done on each switch.
What is the effect of giving the vtp pruning command on a server switch?
VTP pruning is enabled for the whole domain. VLAN flood traffic will be sent
only where it is needed – in the direction of devices on that VLAN.
What happens to the vtp configuration revision number of a switch if you
change its vtp domain name?
It is reset to the default value of 0.
Why might you want to change the domain name of a switch temporarily
before adding it to an existing VTP domain?
If the new switch has a configuration revision number of 0 then there is no
danger of the new switch altering the VLAN information in the VTP domain
and updating it with the wrong information.
Which should you do first on a server, configure the VTP domain name or
create the VLANs?
Configure the domain name first because this will remove existing VLANs.
Which command will make a switch into a VTP client?
vtp mode client
If VTP is not working correctly, what should you check?
VTP Version. It needs to be the same on all switches in the domain.
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Domain name. Is it exactly the same on all switches?
VTP Password if any. Is it exactly the same on all switches?
Check that there is at least one server. Better to have at least two.
If you recently added a new switch, had its revision number been set to 0?
Is it possible to have a VTP domain where all the switches are in server
mode?
Yes.
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