VTP配置及工作原理（实验）

实验目标：理解掌握VTP的配置及其工作原理实验TOP：

基本配置SW1

SW2

R3

基本配置完成。首先，我们看下一下这个案例。如图：

通常情况下，我们需要在整个园区网或者企业网中的一组的交换机中保持VLAN数据库的同步，以保证所有交换机都能从数据帧中读取相关的VLAN信息进行正确的数据转发，然而对于大型网络来说，可能有成百上千台交换机，而一台交换机上都可能存在几十乃至数百个VLAN，如果仅凭网络工程师手工配置的话是一个非常大的工作量，并且也不利于日后维护――每一次添加修改或删除VLAN都需要在所有的交换机上部署。在这种情况下，我们引入了VTP（VLAN Trunking Protocol）。 VTP即VLAN中继协议，也被称为虚拟局域网干道协议，是思科私有协议。VTP有3种模式:服务器模式（Server）；客户机模式（Client）；透明模式（Transparent）。 Server模式：提供VTP消息（包括VLAN ID和名字信息）； 学习相同域名的VTP消息； 转发相同域名的VTP消息； 可以添加、删除和更改VLAN VLAN信息写入NVRAM。 Client模式：请求VTP消息； 学习相同域名的VTP消息； 转发相同域名的VTP消息； 不可以添加、删除和更改VLAN VLAN信息不会写入NVRAM。 Transparent模式：不提供VTP消息； 不学习VTP消息； 转发VTP消息； 可以添加、删除和更改VLAN，只在本地有效VLAN信息写入NVRAM。 新交换机出厂时的默认配置是预配置为VLAN1，VTP 模式为服务器。 在VTP域中有两个重要的概念：　　 VTP域：也称VLAN管理域，由一个以上共享VTP域名的相互连接的交换机组成的。也就是说VTP域是一组域名相同并通过中继链路相互连接的交换机；　 VTP通告：在交换机之间用来传递VLAN信息的数据包被称为VTP数据包。 　　 VTP通告包括：汇总通告，子集通告，通告请求。 　　注意：VTP通过Trunk，VTP Server向其它交换机传输信息和接收更新。若给VTP配置密码，那么本域内的所有交换机的VTP密码必须保持一致。 创建VTP域命令 　switch(config)#vtp domain DOMAIN_NAME　　 配置交换机的VTP模式switch(config)# vtp mode server | client | transparent 　　 配置VTP密码 　　switch (config) # vtp password PASSWORD 　 查看VTP配置信息 　　switch# show vtp status 　实验： 假设一个小型公司由总公司和分公司组成，而总公司和分公司里都有生产部和销售部。 需求：为了不让俩不能各个部门相互影响其工作，并能够使总公司和分公司相同部门成员间能相互通信。 解决方案：分别在总公司和分公司的交换机上配置相同的两个VLAN，分别供生产部和销售部使用，而两公司交换机的借口配为trunk模式。

如上图所示，假设总公司、分公司的交换机命名分别为SW1、SW2，公司规定：交换机fa0/1―10为生产部所使用，fa0/11―20为销售部所使用，剩余接口保留。创建VLAN 10和VLAN 20分别为生产部和销售部所使用。生产部各一成员PC1、PC3，销售部各一成员PC2、PC4分别连接于总公司、分公司交换机，如上图。配置如下：SW1(config)#vlan 10SW1(config-vlan)#exiSW1(config)#vlan 20SW1(config-vlan)#exiSW1(config)#int range f0/1 - f0/10SW1(config-if-range)#switchport mode accessSW1(config-if-range)#switchport access vlan 10SW1(config-if-range)#exiSW1(config)#int range f0/11 - f0/20SW1(config-if-range)#switchport mode accessSW1(config-if-range)#switchport access vlan 20SW1(config-if-range)#exiSW1(config)#int f0/24SW1(config-if)#switchport mode trunkSW1(config-if-range)#endSW1#sh vlanVLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/21, Fa0/22, Fa0/23, Gig1/1 Gig1/210 VLAN0010 active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/1020 VLAN0020 active Fa0/11, Fa0/12, Fa0/13, Fa0/14 Fa0/15, Fa0/16, Fa0/17, Fa0/18 Fa0/19, Fa0/201002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 010 enet 100010 1500 - - - - - 0 020 enet 100020 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------

SW2(config)#vlan 10SW2(config-vlan)#exiSW2(config)#vlan 20SW2(config-vlan)#exiSW2(config)#int range f0/1 - f0/10SW2(config-if-range)#switchport mode accessSW2(config-if-range)#switchport access vlan 10SW2(config-if-range)#exiSW2(config)#int range f0/11 - f0/20SW2(config-if-range)#switchport mode accessSW2(config-if-range)#switchport access vlan 20SW2(config-if-range)#exiSW2(config)#int f0/24SW2(config-if)#switchport mode trunkSW1(config-if-range)#endSW2#sh vlanVLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/21, Fa0/22, Fa0/23, Gig1/1 Gig1/210 VLAN0010 active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/1020 VLAN0020 active Fa0/11, Fa0/12, Fa0/13, Fa0/14 Fa0/15, Fa0/16, Fa0/17, Fa0/18 Fa0/19, Fa0/201002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 010 enet 100010 1500 - - - - - 0 020 enet 100020 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------

实验结果： PC1或PC3 与PC2或PC4 ping 都不通； PC2 与PC4 ping通； PC1 与PC3 ping通。 有此说明：可通过在交换机上创建VLAN以达到把不同位置的PC划分进同一区域或实现同一区域的逻辑划分。 但同时也存着在问题：如果在大型公司，存在着多个不同的部门和分公司，需要更多的交换机上实现VLAN的划分（可能有成百上千台交换机，而一台交换机上都可能存在几十乃至数百个VLAN），如果仅凭网络工程师手工配置的话是一个非常大的工作量，并且也不利于日后维护――每一次添加修改或删除VLAN都需要在所有的交换机上部署。而现在我们使用VTP只需在一台交换机上配置所有VLAN，其他交换机则会自动学习其交换机的VLAN信息。

SW1#sh vtp status 查看SW1VTP配置信息VTP Version : 2Configuration Revision : 0Maximum VLANs supported locally : 255Number of existing VLANs : 5VTP Operating Mode : Server 默认VTP 模式为服务器VTP Domain Name :VTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0x7D 0x5A 0xA6 0x0E 0x9A 0x72 0xA0 0x3AConfiguration last modified by 0.0.0.0 at 0-0-00 00:00:00Local updater ID is 0.0.0.0 (no valid interface found)

SW2#sh vtp status 查看SW2VTP配置信息VTP Version : 2Configuration Revision : 0Maximum VLANs supported locally : 255Number of existing VLANs : 5VTP Operating Mode : Server 默认VTP 模式为服务器VTP Domain Name :VTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0x7D 0x5A 0xA6 0x0E 0x9A 0x72 0xA0 0x3AConfiguration last modified by 0.0.0.0 at 0-0-00 00:00:00Local updater ID is 0.0.0.0 (no valid interface found)

SW3#sh vtp status 查看SW3VTP配置信息VTP Version : 2Configuration Revision : 0Maximum VLANs supported locally : 255Number of existing VLANs : 5VTP Operating Mode : Server 默认VTP 模式为服务器VTP Domain Name :VTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0x7D 0x5A 0xA6 0x0E 0x9A 0x72 0xA0 0x3AConfiguration last modified by 0.0.0.0 at 0-0-00 00:00:00Local updater ID is 0.0.0.0 (no valid interface found) 三台交换机在未作任何VTP配置的情况下自启动VTP，通过查看VTP运行状态命令可以看到：VTP默认模式为服务器（Server）

SW1(config)#vtp domain cisco 在SW1上创建名字为ciscoVTP域Changing VTP domain name from NULL to ciscoSW1(config)#exiSW1#sh vtp statusVTP Version : 2Configuration Revision : 0Maximum VLANs supported locally : 255Number of existing VLANs : 5VTP Operating Mode : ServerVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0xAA 0xB9 0x0C 0xCD 0xD7 0xE8 0xA6 0xE0Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00Local updater ID is 0.0.0.0 (no valid interface found)

SW2#sh vtp statusVTP Version : 2Configuration Revision : 0Maximum VLANs supported locally : 255Number of existing VLANs : 5VTP Operating Mode : ServerVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0xAA 0xB9 0x0C 0xCD 0xD7 0xE8 0xA6 0xE0Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00Local updater ID is 0.0.0.0 (no valid interface found)

SW3#sh vtp statusVTP Version : 2Configuration Revision : 0Maximum VLANs supported locally : 255Number of existing VLANs : 5VTP Operating Mode : ServerVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0xAA 0xB9 0x0C 0xCD 0xD7 0xE8 0xA6 0xE0Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00Local updater ID is 0.0.0.0 (no valid interface found) 在交换机SW1上创建名字为cisco的VTP，交换机SW2和SW3上无任何操作，但他们将自动学习到VTP域名：cisco。

SW2(config)#vlan 10SW2(config-vlan)#endSW2#sh vtp statusVTP Version : 2Configuration Revision : 1 修订版本号由0变为1Maximum VLANs supported locally : 255Number of existing VLANs : 6 VLAN数由5变为6VTP Operating Mode : ServerVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0x50 0xDF 0x49 0x46 0x91 0xEF 0x8B 0x41Configuration last modified by 0.0.0.0 at 3-1-93 00:00:51Local updater ID is 0.0.0.0 (no valid interface found)

SW1#sh vtp statusVTP Version : 2Configuration Revision : 1 修订版本号由0变为1Maximum VLANs supported locally : 255Number of existing VLANs : 6 VLAN数由5变为6VTP Operating Mode : ServerVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0x50 0xDF 0x49 0x46 0x91 0xEF 0x8B 0x41Configuration last modified by 0.0.0.0 at 3-1-93 00:00:51Local updater ID is 0.0.0.0 (no valid interface found)SW1#sh vlan

VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Fa0/24, Gig1/1 Gig1/210 VLAN0010 active 1002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 010 enet 100010 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------

SW3#sh vtp statusVTP Version : 2Configuration Revision : 1 修订版本号由0变为1Maximum VLANs supported locally : 255Number of existing VLANs : 6 VLAN数由5变为6VTP Operating Mode : ServerVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0x50 0xDF 0x49 0x46 0x91 0xEF 0x8B 0x41Configuration last modified by 0.0.0.0 at 3-1-93 00:00:51Local updater ID is 0.0.0.0 (no valid interface found)SW3#sh vlan

VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Fa0/23, Gig1/1 Gig1/210 VLAN0010 active 1002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 010 enet 100010 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------ 交换机SW2因为添加VLAN 10而修订版本号有1变为2，而交换机SW1和SW3修订版本号都为0 < 1，所以自动学习SW2的VLAN配置，自动添加VLAN 10，并同步VTP信息。由此可以看出：添加VLAN可以使VTP修订版本号增大，且在多台交换机VTP都Server模式时，修订版本号越大信息越新，会被其他修订版本号地的交换机学习。

SW2(config)#vtp mode transparent 把交换机SW2设为透明模式Setting device to VTP TRANSPARENT mode.SW2(config)#vlan 30 在交换机SW2上添加VLAN 30SW2(config-vlan)#exiSW1(config)#vtp mode server 把交换机SW1设为服务器模式Device mode already VTP SERVER.SW1(config)#vlan 20 在交换机SW1上添加VLAN 20SW1(config-vlan)#endSW1#sh vtp statusVTP Version : 2Configuration Revision : 2Maximum VLANs supported locally : 255Number of existing VLANs : 7VTP Operating Mode : ServerVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0x8A 0xBD 0xC9 0xDB 0xE2 0x59 0x61 0x29Configuration last modified by 0.0.0.0 at 3-1-93 00:12:55Local updater ID is 0.0.0.0 (no valid interface found)SW1#sh vlan

VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Fa0/24, Gig1/1 Gig1/210 VLAN0010 active 20 VLAN0020 active 1002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 010 enet 100010 1500 - - - - - 0 020 enet 100020 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------

SW2#sh vtp statusVTP Version : 2Configuration Revision : 0Maximum VLANs supported locally : 255Number of existing VLANs : 6VTP Operating Mode : TransparentVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0x2F 0x58 0x29 0x9B 0x10 0x9A 0x42 0x41Configuration last modified by 0.0.0.0 at 3-1-93 00:00:51SW2#sh vlan

VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Gig1/1, Gig1/210 VLAN0010 active 30 VLAN0030 active 1002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 010 enet 100010 1500 - - - - - 0 030 enet 100030 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------

SW3#sh vtp statusVTP Version : 2Configuration Revision : 2Maximum VLANs supported locally : 255Number of existing VLANs : 7VTP Operating Mode : ServerVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0x28 0x2B 0x39 0xF0 0xE3 0xCD 0x25 0xC7Configuration last modified by 0.0.0.0 at 3-1-93 00:06:07Local updater ID is 0.0.0.0 (no valid interface found)SW3#sh vlan

VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Fa0/23, Gig1/1 Gig1/210 VLAN0010 active 20 VLAN0020 active 1002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 010 enet 100010 1500 - - - - - 0 020 enet 100020 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------ 交换机SW1配置为服务器模式，交换机SW2配置为透明模式，交换机SW3未作任何配置，默认为服务器模式。在交换机SW1上添加VLAN 20修订版本再次有1变为2，使交换机SW3自动学习，与交换机SW1同步信息，添加VLAN 20并同步VTP信息；而交换机SW2不同步VLAN配置，只发送、转发通告，所以既不学习VLAN 20，也不会让交换机SW1和SW3学习到VLAN 30，两者更不会同步VTP信息。由此说明：VTP服务器模式的交换机具有建立、修改和删除VLAN，发送、转发通告，同步VLAN配置作用；VTP透明模式的交换机建立、修改和删除本交换机的VLANs，不同步VLAN配置，但发送、转发通告。

SW3(config)#no vlan 20SW3(config)#exiSW3#sh vtp statusVTP Version : 2Configuration Revision : 3Maximum VLANs supported locally : 255Number of existing VLANs : 6VTP Operating Mode : ServerVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0xA8 0x0B 0x21 0x34 0x68 0x53 0xE6 0xC1Configuration last modified by 0.0.0.0 at 3-1-93 00:11:35Local updater ID is 0.0.0.0 (no valid interface found)

SW1#sh vtp statusVTP Version : 2Configuration Revision : 3Maximum VLANs supported locally : 255Number of existing VLANs : 6VTP Operating Mode : ServerVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0xA8 0x0B 0x21 0x34 0x68 0x53 0xE6 0xC1Configuration last modified by 0.0.0.0 at 3-1-93 00:11:35Local updater ID is 0.0.0.0 (no valid interface found)

SW2#sh vtp statusVTP Version : 2Configuration Revision : 0Maximum VLANs supported locally : 255Number of existing VLANs : 7VTP Operating Mode : TransparentVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0x0F 0xB1 0xAC 0x47 0x23 0xFE 0x0A 0x44Configuration last modified by 0.0.0.0 at 3-1-93 00:04:36

在交换机SW3上删除VLAN 20后，其修订版本号由2变为3，使交换机SW1自动学习，与交换机SW3同步信息，删除VLAN 20，并同步VTP版本号信息。而交换机SW2去无任何变化，只向交换机SW1、SW3间相互发送、转发通告。由此看出，添加、删除VLAN都能使修订版本号增大。

SW3(config)#vtp mode clientSetting device to VTP CLIENT mode.SW3(config)#vlan 20VTP VLAN configuration not allowed when device is in CLIENT mode.SW3#sh vtp statusVTP Version : 2Configuration Revision : 3Maximum VLANs supported locally : 255Number of existing VLANs : 6VTP Operating Mode : ClientVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0xF3 0xA4 0x91 0xAC 0x45 0xBD 0x9B 0xB8Configuration last modified by 0.0.0.0 at 3-1-93 00:08:00

SW3(config)#no vlan 10VTP VLAN configuration not allowed when device is in CLIENT mode.SW3#sh vtp statusVTP Version : 2Configuration Revision : 3Maximum VLANs supported locally : 255Number of existing VLANs : 6VTP Operating Mode : ClientVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0xF3 0xA4 0x91 0xAC 0x45 0xBD 0x9B 0xB8Configuration last modified by 0.0.0.0 at 3-1-93 00:08:00

SW1(config)#vlan 20SW1(config-vlan)#endSW1#sh vtp statusVTP Version : 2Configuration Revision : 4Maximum VLANs supported locally : 255Number of existing VLANs : 7VTP Operating Mode : ServerVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0xF2 0x09 0x72 0xEF 0x3B 0x8B 0x28 0x57Configuration last modified by 0.0.0.0 at 3-1-93 00:11:10Local updater ID is 0.0.0.0 (no valid interface found)

SW3#sh vtp statusVTP Version : 2Configuration Revision : 4Maximum VLANs supported locally : 255Number of existing VLANs : 7VTP Operating Mode : ClientVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0xF2 0x09 0x72 0xEF 0x3B 0x8B 0x28 0x57Configuration last modified by 0.0.0.0 at 3-1-93 00:11:10

SW3#sh vlanVLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Fa0/23, Gig1/1 Gig1/210 VLAN0010 active 20 VLAN0020 active 1002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 010 enet 100010 1500 - - - - - 0 020 enet 100020 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------

把交换机SW3配置为客户机模式，然后在交换机上添加VLAN 20，弹出信息：VTP VLAN configuration not allowed when device is in CLIENT mode. （在VTP客户机模式下不能添加VLAN配置）；接着在交换机上删除VLAN 10，弹出信息：VTP VLAN configuration not allowed when device is in CLIENT mode. （在VTP客户机模式下不能删除VLAN配置） 在交换机SW1上添加VLAN 20，其修订版本号由3变为4，交换机SW3自动学习，添加VLAN 20并同步VTP信息。由此说明：VTP客户机模式的交换机不建立、修改和删除VLAN；发送、转发通告；同步VLAN配置。

SW1(config)#vtp password cisco 给交换机SW1配置VTP密码为ciscoSetting device VLAN database password to ciscoSW1(config)# vlan 40 在交换机SW1上添加VLAN 40SW1(config-vlan)#endSW1#sh vlan

VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Fa0/24, Gig1/1 Gig1/210 VLAN0010 active 20 VLAN0020 active 40 VLAN0040 active 1002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 010 enet 100010 1500 - - - - - 0 020 enet 100020 1500 - - - - - 0 040 enet 100040 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------

SW3#sh vlan

VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Fa0/23, Gig1/1 Gig1/210 VLAN0010 active 20 VLAN0020 active 1002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 010 enet 100010 1500 - - - - - 0 020 enet 100020 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------

SW3(config)#vtp password cisco 给交换机SW1配置VTP密码为ciscoSetting device VLAN database password to ciscoSW3(config)#exiSW3#sh vlan

VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Fa0/23, Gig1/1 Gig1/210 VLAN0010 active 20 VLAN0020 active 40 VLAN0040 active 1002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 010 enet 100010 1500 - - - - - 0 020 enet 100020 1500 - - - - - 0 040 enet 100040 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------

在交换机SW1上添加VLAN 40交换机SW3却没有添加，因为再添加VLAN 40前交换机SW1 VTP已添加密码。而在交换机SW3上配上密码，即可自动学习得VLAN 40。由此可见：若给VTP配置密码，那么本域内的所有交换机都必须拥有密码才能相互同步信息。

SW3(config)#no vtp password ciscoClearing device VLAN database password.SW3(config)#vtp password cisc1Setting device VLAN database password to cisc1SW1(config)#vlan 50SW1(config-vlan)#exiSW3#sh vlan

VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Fa0/23, Gig1/1 Gig1/210 VLAN0010 active 20 VLAN0020 active 40 VLAN0040 active 1002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 010 enet 100010 1500 - - - - - 0 020 enet 100020 1500 - - - - - 0 040 enet 100040 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------

SW3(config)#no vtp password cisc1Clearing device VLAN database password.SW3(config)#vtp password ciscoSetting device VLAN database password to cisco

SW3#sh vlan

VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Fa0/23, Gig1/1 Gig1/210 VLAN0010 active 20 VLAN0020 active 40 VLAN0040 active 50 VLAN0050 active 1002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 010 enet 100010 1500 - - - - - 0 020 enet 100020 1500 - - - - - 0 040 enet 100040 1500 - - - - - 0 050 enet 100050 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------

在交换机SW3上VTP使用与SW1不同的密码cisc1，并在交换机SW1上添加VLAN 50，交换机SW3不能学习到，但使用相同的密码cisco，则能学习到。由此可见：若给VTP配置密码，那么本域内的所有交换机不仅要拥有VTP密码而且要必须保持一致才能相互同步信息。

将三台交换机恢复基本配置。SW1(config)#int f0/23SW1(config-if)#no switchport mode trunkSW2(config)#int f0/23SW2(config-if)#no switchport mode trunk

SW1(config)#vtp domain ciscoChanging VTP domain name from NULL to ciscoSW1(config)#exiSW1#sh vtp statusVTP Version : 2Configuration Revision : 0Maximum VLANs supported locally : 255Number of existing VLANs : 5VTP Operating Mode : ServerVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0xAA 0xB9 0x0C 0xCD 0xD7 0xE8 0xA6 0xE0Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00Local updater ID is 0.0.0.0 (no valid interface found)

SW2#sh vtp statusVTP Version : 2Configuration Revision : 0Maximum VLANs supported locally : 255Number of existing VLANs : 5VTP Operating Mode : ServerVTP Domain Name :VTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0x7D 0x5A 0xA6 0x0E 0x9A 0x72 0xA0 0x3AConfiguration last modified by 0.0.0.0 at 0-0-00 00:00:00Local updater ID is 0.0.0.0 (no valid interface found)

SW1(config)#int f0/23SW1(config-if)# switchport mode trunkSW2(config)#int f0/23SW2(config-if)# switchport mode trunk

SW2#sh vtp statusVTP Version : 2Configuration Revision : 0Maximum VLANs supported locally : 255Number of existing VLANs : 5VTP Operating Mode : ServerVTP Domain Name : ciscoVTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0xAA 0xB9 0x0C 0xCD 0xD7 0xE8 0xA6 0xE0Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00Local updater ID is 0.0.0.0 (no valid interface found)

使交换机SW1和SW2相连的接口模式变为默认，则交换机SW2不能学到VTP域名cisco。由此说明：VTP通过Trunk向其它交换机传输信息和接收更新。

SW1(config)#vlan 10SW1(config-vlan)#exiSW1(config)#vlan 20SW1(config-vlan)#exiSW2(config)#vlan 30SW2(config-vlan)#exiSW2(config)#vlan 40SW2(config-vlan)#exi

SW1(config)#int f0/23SW1(config-if)# switchport mode trunkSW2(config)#int f0/23SW2(config-if)# switchport mode trunk

SW1#sh vlan

VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Fa0/24, Gig1/1 Gig1/210 VLAN0010 active 20 VLAN0020 active 1002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 010 enet 100010 1500 - - - - - 0 020 enet 100020 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------

SW2#sh vlan

VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Gig1/1, Gig1/230 VLAN0030 active 40 VLAN0040 active 1002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 030 enet 100030 1500 - - - - - 0 040 enet 100040 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------

SW2(config)#vlan 50SW2(config-vlan)#exi

SW2#sh vlan

VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Gig1/1, Gig1/210 VLAN0010 active 20 VLAN0020 active 50 VLAN0050 active 1002 fddi-default act/unsup1003 token-ring-default act/unsup1004 fddinet-default act/unsup1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 0 010 enet 100010 1500 - - - - - 0 020 enet 100020 1500 - - - - - 0 050 enet 100050 1500 - - - - - 0 01002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs------------------------------------------------------------------------------

Primary Secondary Type Ports------- --------- ----------------- ------------------------------------------

在交换机SW1上添加VLAN 10、VLAN 20，交换机SW2上添加VLAN 30、VLAN 40，交换机SW1和交换机SW2修订版本号相同，而在交换机SW1上添加VLAN 50，修订版本号由2变为3，所以交换机SW2自动学习交换机SW1VLAN配置，而交换机SW2原有的VLAN配置却被清空。由此说明：交换机通过VTP相互学习信息的方式是覆盖式学习的方式。

总结： 在企业网中，配置VLAN工作量大，可以使用VTP协议。VTP通过网络(ISL帧或cisco私有DTP帧)保持VLAN配置统一性。VTP在系统级管理增加，删除，调整的VLAN，自动地将信息向网络中其它的交换机广播。此外，VTP减小了那些可能导致安全问题的配置。便于管理,只要在vtp server做相应设置,vtp client会自动学习vtp server上的vlan信息。

优点

1.保持配置的一致性；2.提供跨不同介质类型如ATM FDDI和以太网配置虚拟局域网的方法；3.提供跟踪和监视虚拟局域网的方法；4.提供检测加到另一个交换机上的虚拟局域的方法；5.提供从一个交换机在整个管理域中增加虚拟局域网的方法。

缺点

1.覆盖式学习，当交换机学习完其他交换机上的VLAN配置后本交换机的VLAN配置也会被清空；2.VTP通过Trunk，VTP Server向其它交换机传输信息和接收更新。若未给VTP配置密码，则所有通过Trunk相连的交换机都会学习到相同的VLAN配置。

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