1.删除之前导入的ios；
2.选择GNS3——Edit——Preferences——IOS routers——New——导入ios—— 勾选This is an EtherSwitch router——next……——默认选择添加了nm-16esw（如无则加上）——计算idle值——Finish；
3.在gns3左侧找到browse all devices，选择刚刚命名的EtherSwitch router即可；
4.验证成功创建vlan。ESW1(config)#no ip routing
ESW1(config)#exit
ESW1#vlan database
% Warning: It is recommended to configure VLAN from config mode,
as VLAN database mode is being deprecated. Please consult user
documentation for configuring VTP/VLAN in config mode.
ESW1(vlan)#vlan 200
VLAN 200 modified:
ESW1(vlan)#exit
APPLY completed.
Exiting....
ESW1#show vlan-sw
ESW1#show vlan-switch
VLAN Name Status Ports
1 default active Fa1/0, Fa1/2, Fa1/3, Fa1/4
Fa1/5, Fa1/6, Fa1/7, Fa1/8
Fa1/9, Fa1/10, Fa1/11, Fa1/12
Fa1/13, Fa1/14, Fa1/15
200 VLAN0200 active Fa1/1
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup
VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
1 enet 100001 1500 - - - - - 1002 1003
200 enet 100200 1500 - - - - - 0 0
1002 fddi 101002 1500 - - - - - 1 1003
1003 tr 101003 1500 1005 0 - - srb 1 1002
1004 fdnet 101004 1500 - - 1 ibm - 0 0
1005 trnet 101005 1500 - - 1 ibm - 0 0
问题的关键在于导入ios的时候就要选择设置为多层交换机，This is an EtherSwitch router.最后这句很重要！
我搞了一天，终于在第二天才解决。有时候连基本的问题都没解决，实验无法继续下去，这种沮丧很痛苦。但解决出来也很兴奋。与诸君共享。