Here we are Once again! Now on VTP ( Vlan Trunk Protocol ) lets see Cisco Definition of VTP ( for general Knowledge purpose ).
VLAN Trunk Protocol (VTP) reduces administration in a switched network. When you configure a new VLAN on one VTP server, the VLAN is distributed through all switches in the domain. This reduces the need to configure the same VLAN everywhere. VTP is a Cisco-proprietary protocol that is available on most of the Cisco Catalyst series products.
Here is the Rest of the Document ( http://www.cisco.com/en/US/tech/tk389/tk68/technologies_tech_note09186a0080094c52.shtml ).
Configuring VTP.
-Configuring VTP Domain.
-Configuring VTP Password.
-Configuring VTP Server/Client/transparent.
-Configuring VTP Prunning.
-Troubleshooting VTP.
I have to see configuring VTP is pretty Much simple , so this will not be extensive!.
Remenber i Realize you know how to make basic configuration ( hostname,password,etc ). so i`ll just go to configuration Section.
Topology this will be pretty simple, 3 switches , 1 2960-24TT and 2 2950T-24, i was going to use 3 3640 Routers with the NM-16ESW but, configuration commands will be kinda different and in different modes, so i decided to stick to PKT devices.
This Time i will not Post Topology Picture ( some tecnical issues !!!1 ) and this is pretty much straightfoward so i realize you `ll understand, Here is the Setup.
Hostnames SW1,SW2,SW3
SW1 F0/24 To SW2 F0/14
SW1 F0/23 To SW2 F0/23
SW1 F0/22 To SW3 F0/24
SW1 F0/21 To SW3 F0/23.
SW1 Basic Conf.
SW1#show running-config
Building configuration…
Current configuration : 1117 bytes
!
version 12.2
service password-encryption
!
hostname SW1
!
enable secret 5 $1$mERr$hx5rVt7rPNoS4wqbXKX7m0
!
!
!
interface FastEthernet0/1
!
interface FastEthernet0/2
!
interface FastEthernet0/3
!
interface FastEthernet0/4
!
interface FastEthernet0/5
!
interface FastEthernet0/6
!
interface FastEthernet0/7
!
interface FastEthernet0/8
!
interface FastEthernet0/9
!
interface FastEthernet0/10
!
interface FastEthernet0/11
!
interface FastEthernet0/12
!
interface FastEthernet0/13
!
interface FastEthernet0/14
!
interface FastEthernet0/15
!
interface FastEthernet0/16
!
interface FastEthernet0/17
!
interface FastEthernet0/18
!
interface FastEthernet0/19
!
interface FastEthernet0/20
!
interface FastEthernet0/21
!
interface FastEthernet0/22
!
interface FastEthernet0/23
!
interface FastEthernet0/24
!
interface GigabitEthernet1/1
!
interface GigabitEthernet1/2
!
interface Vlan1
ip address 192.168.1.1 255.255.255.0
!
line con 0
password 7 0822455D0A16
login
exec-timeout 6 0
!
line vty 0 4
exec-timeout 6 0
password 7 0822455D0A16
login
line vty 5 15
exec-timeout 6 0
password 7 0822455D0A16
login
!
!
end
SW2 conf.
SW2#show running-config
Building configuration…
Current configuration : 1150 bytes
!
version 12.1
service password-encryption
!
hostname SW2
!
enable secret 5 $1$mERr$hx5rVt7rPNoS4wqbXKX7m0
!
!
!
interface FastEthernet0/1
!
interface FastEthernet0/2
!
interface FastEthernet0/3
!
interface FastEthernet0/4
!
interface FastEthernet0/5
!
interface FastEthernet0/6
!
interface FastEthernet0/7
!
interface FastEthernet0/8
!
interface FastEthernet0/9
!
interface FastEthernet0/10
!
interface FastEthernet0/11
!
interface FastEthernet0/12
!
interface FastEthernet0/13
!
interface FastEthernet0/14
!
interface FastEthernet0/15
!
interface FastEthernet0/16
!
interface FastEthernet0/17
!
interface FastEthernet0/18
!
interface FastEthernet0/19
!
interface FastEthernet0/20
!
interface FastEthernet0/21
!
interface FastEthernet0/22
!
interface FastEthernet0/23
!
interface FastEthernet0/24
!
interface GigabitEthernet1/1
!
interface GigabitEthernet1/2
!
interface Vlan1
ip address 192.168.1.2 255.255.255.0
!
ip default-gateway 192.168.1.1
!
line con 0
password 7 0822455D0A16
login
exec-timeout 6 0
!
line vty 0 4
exec-timeout 6 0
password 7 0822455D0A16
login
line vty 5 15
exec-timeout 6 0
password 7 0822455D0A16
login
!
!
end
SW3 Conf.
SW3#show running-config
Building configuration…
Current configuration : 1150 bytes
!
version 12.1
service password-encryption
!
hostname SW3
!
enable secret 5 $1$mERr$hx5rVt7rPNoS4wqbXKX7m0
!
!
!
interface FastEthernet0/1
!
interface FastEthernet0/2
!
interface FastEthernet0/3
!
interface FastEthernet0/4
!
interface FastEthernet0/5
!
interface FastEthernet0/6
!
interface FastEthernet0/7
!
interface FastEthernet0/8
!
interface FastEthernet0/9
!
interface FastEthernet0/10
!
interface FastEthernet0/11
!
interface FastEthernet0/12
!
interface FastEthernet0/13
!
interface FastEthernet0/14
!
interface FastEthernet0/15
!
interface FastEthernet0/16
!
interface FastEthernet0/17
!
interface FastEthernet0/18
!
interface FastEthernet0/19
!
interface FastEthernet0/20
!
interface FastEthernet0/21
!
interface FastEthernet0/22
!
interface FastEthernet0/23
!
interface FastEthernet0/24
!
interface GigabitEthernet1/1
!
interface GigabitEthernet1/2
!
interface Vlan1
ip address 192.168.1.3 255.255.255.0
!
ip default-gateway 192.168.1.1
!
line con 0
password 7 0822455D0A16
login
exec-timeout 6 0
!
line vty 0 4
exec-timeout 6 0
password 7 0822455D0A16
login
line vty 5 15
exec-timeout 6 0
password 7 0822455D0A16
login
!
!
end
Configuring VTP Domain.
The first Step in configuring VTP its setting the DOmain on which de Server and CLient will be in.
SW1(config)#vtp domain cisco
Changing VTP domain name from NULL to cisco ! This is the Message You should see when you configure the domain name.
On SW2
SW2(config)#vtp domain cisco
Changing VTP domain name from NULL to cisco.
Pretty Simple.
Configuring VTP Password.
Note: VTP Password if you configure a password for VTP, you must configure the password on all switches in the VTP domain. The password must be the same password on all those switches. The VTP password that you configure is translated by algorithm into a 16-byte word (MD5 value) that is carried in all summary-advertisement VTP packets.
The second Step ( another Pretty simple step. )
SW1(config)#vtp password cisco
Setting device VLAN database password to cisco ! This is the message Again that shows that the password has changed.
On SW2.
SW2(config)#vtp password cisco
Setting device VLAN database password to cisco
Configuring VTP Server/Client/transparent.
Ok now to Terms.
You can configure a switch to operate in any one of these VTP modes:
- Server—In VTP server mode, you can create, modify, and delete VLANs and specify other configuration parameters, such as VTP version and VTP pruning, for the entire VTP domain. VTP servers advertise their VLAN configuration to other switches in the same VTP domain and synchronize their VLAN configuration with other switches based on advertisements received over trunk links. VTP server is the default mode.
- Client—VTP clients behave the same way as VTP servers, but you cannot create, change, or delete VLANs on a VTP client.
- Transparent—VTP transparent switches do not participate in VTP. A VTP transparent switch does not advertise its VLAN configuration and does not synchronize its VLAN configuration based on received advertisements, but transparent switches do forward VTP advertisements that they receive out their trunk ports in VTP Version 2.
SW1(config)#vtp mode server
Device mode already VTP SERVER. ! Cisco Switches by default come in the Server VTP mode.
On SW2 ( Client Switch ).
SW2(config)#vtp mode client
Setting device to VTP CLIENT mode.
On SW3 ( Transparent Switch ).
SW3(config)#vtp mode transparent
Setting device to VTP TRANSPARENT mode.
Configuring VTP Prunning.
VTP Pruning
VTP ensures that all switches in the VTP domain are aware of all VLANs. However, there are occasions when VTP can create unnecessary traffic. All unknown unicasts and broadcasts in a VLAN are flooded over the entire VLAN. All switches in the network receive all broadcasts, even in situations in which few users are connected in that VLAN. VTP pruning is a feature that you use in order to eliminate or prune this unnecessary traffic.
This can be set with the global command “set vtp pruning enable” or entering the vlan database mode issuing “vlan database” in EXec mode, then “vtp prunning”.
Troubleshooting VTP.
There are a couple of show commands that will be very useful in the time to Troubleshoot VTP.
show vtp status.
show vtp counter.
show vtp password.
This are the main ones ( yes i know this commands Vary depending on Plataform and IOS, this i CCNA focus i`m not going to post different Plataforms COnfigs and any other unrelated stuff ).
Examples of show Commands.
show vtp status
SW1#show vtp status
VTP Version : 2
Configuration Revision : 0
Maximum VLANs supported locally : 255
Number of existing VLANs : 5
VTP Operating Mode : Server
VTP Domain Name : cisco
VTP Pruning Mode : Disabled
VTP V2 Mode : Disabled
VTP Traps Generation : Disabled
MD5 digest : 0xAB 0x8A 0xB6 0xF8 0×91 0×34 0×79 0xDA
Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00
Local updater ID is 192.168.1.1 on interface Vl1 (lowest numbered VLAN interface found)
Show vtp Counter.
SW1#show vtp counters
VTP statistics:
Summary advertisements received : 0
Subset advertisements received : 0
Request advertisements received : 0
Summary advertisements transmitted : 0
Subset advertisements transmitted : 0
Request advertisements transmitted : 0
Number of config revision errors : 0
Number of config digest errors : 0
Number of V1 summary errors : 0
VTP pruning statistics:
Trunk Join Transmitted Join Received Summary advts received from
non-pruning-capable device
—————- —————- —————- —————————
show vtp password.
SW1#show vtp password
VTP Password: cisco
Ok now, for you to see VTP operations there you have to consider some more stuff, First of all the links between the Switches should be set up to trunk mode. You can do this with the “Switchport mode trunk” on interfaces mode, remenber the trunk must be set up in both side of the link ( meaning on both switches interchanging vlan info ).
The next thing you should consider is VLANS , you have to set up vlans on the vlan database ( which is saved on the vlan.dat file in the flash memory ,not on the NVRAM ), cause this will be the info VTP is Going to Exchange ( pretty obvious ) you can set vlans in the vlan database mode ( “vlan database” on EXEc mode ) then using “vlan x” x being the number of the vlan you are adding , you can also use names “vlan 2 name Accounting” and so on.
I will stop now, but i know this post lacks lots of information Regarding this subject, i would advice if someone reads this post to not, used it to learn VTP ,trunks and VLANS, use the information on Cisco Website, this information is for Quick reference as you may know ( if not read the Post related to the FOcus of this Blog ).
i leave you guys for now, i have to take care of something and keep reading ( lol ), in the future i`ll post a real document on Vlans and VTP.
