VTP Configuration
Before VLANs can be configured, VTP charge be configured. By default, every about-face will
operate in VTP server approach for the administration area NULL, with no countersign or secure
mode. The afterward sections altercate the commands and considerations that should be acclimated to
configure a about-face for VTP operation.
Configuring a VTP Administration Domain
Before a about-face is added into a network, the VTP administration area should be identified. If
this about-face is the aboriginal one on the network, the administration area will charge to be created.
Otherwise, the about-face may accept to accompany an absolute administration area with added existing
switches.
Configuring a VTP Administration Area on an IOS-Based Switch
The afterward command can be acclimated to accredit a about-face to a administration domain, area the
domain-name is a argument cord up to 32 characters long.
Switch# vlan database
Switch(vlan)# vtp area domain-name
Configuring a VTP Administration Area on a CLI-Based Switch
Similar to the command to accredit a about-face to a administration area on an IOS-based switch,
the afterward command does the aforementioned for a CLI-based switch:
Switch(enable) set vtp [domain domain-name]
Configuring the VTP Mode
Next, the VTP approach needs to be called for the new switch. The three VTP modes of operation
and their guidelines for use are as follows:
• Server mode—Server approach can be acclimated on any about-face in a administration domain, alike if
other server and applicant switches are in use. This approach provides some back-up in the
event of a server abortion in the domain. However, anniversary VTP administration area must
have at atomic one server. The aboriginal server authentic in a arrangement additionally defines the management
domain that will be acclimated by approaching VTP servers and clients. Server approach is the default
VTP mode.
• Applicant mode—If added switches are in the administration domain, a new about-face should be
configured for applicant approach operation. In this way, the about-face will apprentice any absolute VTP
information from a server.
120 Affiliate 4: VLANs and Trunking
If this about-face will be acclimated as a bombastic server, it should alpha out in applicant mode
to apprentice all VTP advice from reliable sources. If the about-face was initially
configured for server approach instead, it ability bear incorrect advice to
the added area switches. Once the about-face has abstruse the accepted VTP
information, it can be reconfigured for server mode.
• Cellophane mode—This approach is acclimated if a about-face is not activity to allotment VLAN
information with any added about-face in the network. VLANs can still be created, deleted, and
renamed on the cellophane switch. However, they will not be advertised to other
neighboring switches. VTP advertisements accustomed by a cellophane about-face will be
forwarded on to added switches on block links.
• Keeping switches in cellophane approach can annihilate the adventitious for duplicate, overlapping
VLANs in a ample arrangement with abounding arrangement administrators. For example, two
administrators ability configure VLANs on switches in their corresponding areas, but use the
same VLAN identification or VLAN number. Alike admitting the two VLANs accept different
meanings and purposes, they could overlap if both administrators advertised them using
VTP.
Configuring the VTP Approach on an IOS-Based Switch
On an IOS-based switch, the VTP approach can be configured with the afterward arrangement of
commands:
Switch# vlan database
Switch(vlan)# vtp area domain-name
Switch(vlan)# vtp {server | applicant | transparent}
Switch(vlan)# vtp countersign password
Configuring the VTP Approach on a CLI-Based Switch
On a CLI-based switch, the VTP approach can be configured with the afterward command:
Switch(enable) set vtp [domain domain-name] [mode {server | applicant | transparent}]
[passwd password]
If the area is operating in defended mode, a countersign can be included in the command line.
The countersign charge be a cord of 8 to 64 characters.
Configuring the VTP Version
Two versions of VTP are accessible for use in a administration domain. Catalyst switches are
capable of active either VTP adaptation 1 or VTP adaptation 2. Within a administration domain, the
two versions are not interoperable. Therefore, the aforementioned VTP adaptation charge be configured on
each about-face in a domain. VTP adaptation 1 is the absence agreement on a switch.
VTP Agreement 121
If a about-face is able of active VTP adaptation 2, however, a about-face may coexist with other
version 1 switches, as continued as its VTP adaptation 2 is not enabled. This bearings becomes
important if you appetite to use adaptation 2 in a domain. Then, alone one server approach about-face needs
to accept VTP adaptation 2 enabled. The new adaptation cardinal is broadcast to all added version
2-capable switches in the domain, causing them all to automatically accredit adaptation 2 for use.
By default, VTP adaptation 1 is enabled. Adaptation 2 can be enabled or disabled application the v2 option.
The two versions of VTP alter in the appearance they support. VTP adaptation 2 offers the following
additional appearance over adaptation 1:
• Version-dependent cellophane mode—VTP adaptation 1 in cellophane approach matches the
VTP adaptation and area name afore forwarding the advice to added switches using
VTP. VTP adaptation 2 in cellophane approach differs by forwarding the VTP letters without
checking the adaptation number. Because alone one area is accurate in a switch, the
domain name doesn’t accept to be checked.
• Bendability checks—VTP adaptation 2 performs bendability checks on the VTP and
VLAN ambit entered from the CLI or by Simple Arrangement Administration Protocol
(SNMP). This blockage helps anticipate errors in such things as VLAN names and numbers
from actuality broadcast to added switches in the domain. However, no bendability checks
are performed on VTP letters that are accustomed on block links or on agreement and
database abstracts that is apprehend from NVRAM.
• Token Ring support—VTP adaptation 2 supports the use of Token Ring switching and
Token Ring VLANs. (If Token Ring switching is actuality used, VTP adaptation 2 charge be
enabled.) The area “Token Ring VLANs” after in this affiliate discusses these capacity in
detail.
• Anonymous Type-Length-Value (TLV) support—VTP adaptation 2 switches will
propagate accustomed agreement change letters out added block links, alike if the
switch administrator is not able to anatomize or accept the message. For example, a VTP
advertisement contains a Blazon acreage to denote what blazon of VTP bulletin is actuality sent.
VTP bulletin blazon 1 is a arbitrary advertisement, and bulletin blazon 2 is a subset
advertisement. An addendum to VTP could be in use that utilizes added bulletin types and
other bulletin breadth values. Instead of bottomward the anonymous VTP message, version
2 will still bear the advice and accumulate a archetype in NVRAM.
Configuring the VTP Adaptation on an IOS-Based Switch
On an IOS-based switch, the VTP adaptation cardinal is configured application the afterward commands:
Switch# vlan database
Switch(vlan)# vtp v2-mode
122 Affiliate 4: VLANs and Trunking
Configuring the VTP Adaptation on a CLI-Based Switch
On a CLI-based switch, the VTP adaptation cardinal is configured application the afterward command:
Switch(enable) set vtp v2 enable
NOTE Abounding abstracted VTP options can be accustomed in a distinct set vtp command, if desired. Consider the
following example:
Switch(enable) set vtp area mayberry approach server countersign opie9 v2 enable
Here, one command has set the VTP administration area name to mayberry, enabled VTP
server mode, set the VTP countersign to opie9, and enabled VTP adaptation 2.
VTP Status
The accepted VTP ambit for a administration area can be displayed. On an IOS-based
switch, use the appearance vtp cachet command. On a CLI-based switch, use the appearance vtp domain
command. Archetype 4-2 demonstrates some sample achievement of this command on a CLI-based
switch.
VTP bulletin and absurdity counters can additionally be displayed with the appearance vtp counters IOS-based
command and the appearance vtp statistics CLI-based command. This command can be acclimated for
basic VTP troubleshooting to see if the about-face is interacting with added VTP nodes in the
domain. Archetype 4-3 demonstrates some sample achievement from the appearance vtp statistics
command.
Example 4-2 appearance vtp area Reveals VTP Ambit for a Administration Domain
Switch> appearance vtp domain
Domain Name Area Index VTP Adaptation Local Approach Password
-------------------------------- ------------ ----------- ----------- ----------
mydomain 1 2 server -
Vlan-count Max-vlan-storage Config Afterlight Notifications
---------- ---------------- --------------- -------------
15 1023 7 disabled
Last Updater V2 Approach Pruning PruneEligible on Vlans
--------------- ------- -------- -------------------------
192.168.1.4 enabled disabled 2-1000
Switch>
show vtp statistics Reveals VTP Bulletin and Absurdity Counters
Switch> appearance vtp statistics
VTP statistics:
summary advts accustomed 8
subset advts accustomed 11
request advts accustomed 0
summary advts transmitted 1
subset advts transmitted 1
request advts transmitted 0
No of config afterlight errors 0
No of config abstract errors 0
VTP pruning statistics:
Trunk Accompany Transmitted Accompany Accustomed Arbitrary advts accustomed from
non-pruning-capable device
-------- --------------- ------------- ---------------------------
3/1
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