[Ccna Study Notes] VTP

1.1 Introduction

After a Cisco switch activates a trunk line (trunk), the switch uses the bulletin board to indicate which VLANs are available and maintains VLAN-related information, this function is called VLAN relay protocol (VLAN Trunking Protocol, VTP for short ). It belongs to the Cisco private protocol.

1.1.1 role

VTP is responsible for synchronizing VLAN information in The VTP domain. In this way, you can configure a vtp server switch and VLAN, and set the remaining switches to VTP clients so that they can learn VLAN information automatically, simplify the configuration process.

1.1.2 VTP features

VTP is a message protocol that uses layer-3 frames and transmits them through vlan1. It manages VLAN addition, deletion, and rename on the basis of the entire network to achieve consistent VLAN configuration.

VTP uses VTP announcements (VTP advertisements) to transmit VLAN information between vswitches. VTP announcements can only interact on the trunk link.

1.1.3 default VTP Information

SW1 # Show VTP Status view VTP information SW1 (config) # VTP version 1 or 2 modify VTP version

1.1.4 VTP domain name (domains)

To allow a vswitch to spread VTP information to other switches, The vswitch must have a VTP domain name, and other switches must be in the same domain.

1.1.5 VTP announcement (advertising)

Notification Type: Summary advertisements)

Subset advertisements)

Request advertisements)

1.1.6 VTP mode (modes)

(1) server mode: You can create, modify, and delete VLANs. Advertise your own VLAN information to other switches in the same domain, and also receive VTP notifications to synchronize VLAN information.

(2) Client mode: you cannot create, modify, or delete VLANs. Advertise your own VLAN information to other switches in the same domain, and also receive VTP notifications to synchronize VLAN information.

(3) transparent mode: You can create, modify, and delete VLANs, but modifications only affect you. Forward VTP notifications to other vswitches in the network, but only forward them, neither send their own VTP information nor synchronize VTP with other vswitches.

	VTP SERVER	VTP Client	VTP transparent
Can I create, modify, and delete VLANs?	√	×	√
Can I send a VTP announcement?	√	√	Only the received VTP notifications can be forwarded, and no VTP notifications will be sent.
Can I synchronize VTP announcements?	√	√	×
Location where VLAN information is stored	VLAN. dat	VLAN. dat	Startup-config

1.1.7 VTP cropping (pruning)

VTP pruning is a function of VTP. It can reduce unnecessary information on the relay port and automatically cut out VLAN information not available on the neighbor switch. Cisco is disabled by default.

1.2 VTP configuration and troubleshooting

1.2.1 VTP configuration considerations

1. Configure VTP SERVER

Make sure that all the switches to be configured are restored to the default settings. We recommend that you configure at least two VTP servers to back up each other.

● VTP domain names are case sensitive

● If The VTP password is configured, make sure that the passwords of all vswitches In The VTP domain are the same

● Ensure that all vswitches are configured with the same VTP Protocol version.

● Ensure that the interconnection links between switches are trunk links

2. Configure The VTP Client

● Configure VTP client Mode

● Configure trunk

● Verify the VTP status

● Configure the access port. When a vswitch works in VTP client mode, a new VLAN cannot be added, but a port can be allocated to an existing VLAN.

1.2.2 VTP Configuration

1. Restore factory Configuration

Switch # erase startup-config Delete STARTUP configuration file switch # Delete VLAN. dat Delete VLAN configuration file

2. configure all trunk links

3. Configure VTP transparent

Sw3 (config) # VTP mode transparent set VTP mode to tracnsparentsw3 (config) # VTP domain ccna configure VTP domain name to ccna, you can also set it to other

4. Configure The vtp server Switch

SW1 (config) # VTP domain ccna configure VTP domain name SW1 (config) # VLAN 2 create vlansw1 (config-VLAN) # VLAN 3

5. Configure The VTP client Switch

Sw2 (config) # VTP mode client configure VTP mode to client

1.2.3 VTP troubleshooting

● Inconsistent VTP versions

● VTP password Problems

● VTP domain name problems

● VTP mode configuration is correct

● Fixed number Configuration

Sw4 # debug Sw-vlan vtp events monitoring VTP events

Sw4 (config) # After VTP domain test changes the domain name at will, The VTP configuration correction number is restored to 0. You cannot randomly access vswitches with VTP to the network, otherwise, the entire network may be paralyzed. Make sure that the correct number is restored to 0.

[Ccna Study Notes] VTP