Bài viết sưu tầm

 

Tại sao lại cần VTP:

“VTP allows a network manager to configure a switch so that it will propagate VLAN configurations to other switches in the network”

 

VTP minimizes misconfigurations and configuration inconsistencies that can cause problems, such as duplicate VLAN names or incorrect VLAN-type specifications. VTP helps you simplify management of the VLAN database across multiple switches.

VTP is a Cisco-proprietary protocol and is available on most of the Cisco switches.

 

Why we need VTP?

Suppose you are working in a medium company in a 5-floor office. You assigned each floor to a switch for easy management and of course they can be assigned to different VLANs. For example, your bosses can sit in any floor and still access Manage VLAN (VLAN 7). Your technical colleagues can sit anywhere on the floors to access Technical VLAN (VLAN 4). This is the best design because each person’s permission is not limited by the physical location.

 

How VTP Works

+ To make switches exchange their VLAN information with each other, they need to be configured in the same VTP domain. Only switches belonging to the same domain share their VLAN information. When a change is made to the VLAN database, it is propagated to all switches via VTP advertisements.

+ To maintain domain consistency, only one switch should be allowed to create (or delete, modify) new VLANs. This switch is like the “master” of the whole VTP domain and it is operated in Server mode. This is also the default mode.

+ Other switches are only allowed to receive and forward updates from the “server” switch. They are operated in Client mode. Switches in this mode cannot create, delete or modify VLANs.

+ VTP Version: displays the VTP version the switch is running. By default, the switch runs version 1 but can be set to version 2. Within a domain, the two VTP versions are not interoperable so make sure to configure the same VTP version on every switch in a domain.

+ Configuration Revision: current Revision number on this switch.

+ Maximum VLANs Supported Locally: maximum number of VLANs supported locally.

+ Number of Existing VLANs: Number of existing VLANs.

+ VTP Operating Mode: can be server, client, or transparent.

+ VTP Domain Name: name that identifies the administrative domain for the switch.

 

Một số thông số VPT:

+ VTP Pruning Mode: displays whether pruning is enabled or disabled. We will discuss about VTP Pruning later.

+ VTP V2 Mode: displays if VTP version 2 mode is enabled. VTP version 2 is disabled by default.

+ VTP Traps Generation: displays whether VTP traps are sent to a network management station.

+ MD5 Digest: a 16-byte checksum of the VTP configuration.

+ Configuration Last Modified: date and time of the last configuration modification. Displays the IP address of the switch that caused the configuration change to the database.