300-115 STP Case 问题

mineave0206

答案是A，解释的原因是SW1和SW2都是Server模式，但是SW1是Primary Server for VLAN Database. 在SW2上是无法新增VLAN的. 我觉得正确答案应该是B.

Question3

You are adding new VLANs: VLAN500 and VLAN600 to the topology in suchway that you need to configure SW1 as primary root for VLAN 500 and secondaryfor VLAN 600 and SW2 as primary root for VLAN 600 and secondary for VLAN 500.Which configuration step is valid?

A. Configure VLAN 500 & VLAN600 on both SW1 & SW2

B. Configure VLAN 500 and VLAN 600 on SW1 only

C. Configure VLAN 500 and VLAN 600 on SW2 only

D. Configure VLAN 500 and VLAN 600 on SW1, SW2 and SW4

E. On SW2; configure vtp mode as off and configure VLAN 500 and VLAN600; configure back to vtp server mode.

SW2#show vtp status

VTP Version capable             : 1 to 3

VTP version running             : 3

VTP Domain Name                 : CCNP

VTP Pruning Mode                : Disabled

VTP Traps Generation            : Disabled

Device ID                       : aabb.cc80.2000

Feature VLAN:

--------------

VTP Operating Mode                : Server

Number of existing VLANs          : 5

Number of existing extended VLANs : 0

Maximum VLANs supported locally   : 4096

Configuration Revision            : 1

Primary ID                        : aabb.cc80.1000

Primary Description               : SW1

MD5 digest                        : 0x99 0x0F 0x78 0x48 0xDF 0x4A 0xDD 0xBE

                                    0x2C 0xA9 0x09 0xF8 0xE6 0xFE 0x01 0xEE

Feature MST:

--------------

VTP Operating Mode                : Transparent

         

Feature UNKNOWN:

--------------

VTP Operating Mode                : Transparent

SW2#conf

Configuring from terminal, memory, or network [terminal]?

Enter configuration commands, one per line.  End with CNTL/Z.

SW2(config)#vlan 500,600

VTP VLAN configuration not allowed when device is not the primary server for vlan database.

SW2(config)#

larry.liang

SW1 as primary root for VLAN 500 SW2 as primary root 所以两个都 是server模式。都可以增加

laputaxu

其实我也没去尝试真的放vlan进去sw2
但是我记得sw1和sw2别的vlan都有放,相应的500，600也要都放，我是这么理解的
sw4是没有的，因为是client

mineave0206

larry.liang 发表于 2019-12-31 14:22
SW1 as primary root for VLAN 500 SW2 as primary root 所以两个都 是server模式。都可以增加

SW1和SW2分别是VLAN 500和VLAN 600的根桥，这跟STP相关，跟VTP没有关系. 我后面看到答案了，SW1并不是Primary Server，所以要么就同时配置，要么就SW1或者SW2，可能出题者就是这个意思吧

Toys

By issuing the "show vtp status command on SW2, SW2, and SW4 we see that both SW1 and SW2 are operating in
VTP server mode, but SW4 is a client, so we will need to add both VLANs to SW1 and SW2.