switchport;pvid;20
switchport;trunk;vlan-allowed;20,24
switchport;trunk;vlan-untagged;20,24
!
interface;FastEthernet0/21
switchport;mode;trunk
switchport;pvid;21
switchport;trunk;vlan-allowed;21,24
switchport;trunk;vlan-untagged;21,24
!
interface;FastEthernet0/22
switchport;mode;trunk
switchport;pvid;22
switchport;trunk;vlan-allowed;22,24
switchport;trunk;vlan-untagged;22,24
!
interface;FastEthernet0/23
switchport;mode;trunk
switchport;pvid;23
switchport;trunk;vlan-allowed;23-24
switchport;trunk;vlan-untagged;23-24
!
interface;FastEthernet0/24;;;;//端口24,本例中作为上行口
switchport;mode;trunk;//设为trunk模式
switchport;pvid;24;;;;;;;//数据入端口时加上vlan24的tag
switchport;trunk;vlan-untagged;all;;//数据出端口时去除所有tag(tag1~tag24)
!;//注重trunk口时默认属于所有tag的!
vlan;1-24;;;;;//建立1~24个vlan,默认情况下只有vlan1,其他需要增加,且这个操作时第一步要做的!
!
!说明,本例子完成之后,interface;f0/1~f/23分别属于不同的vlan,相互之间是不能互通的(不考虑使用三层路由转发的情况),但此时这23个端口都能与上行口interface;f0/24口通讯!
此时的vlan分配情况为:
Switch_config#show;vlan
VLAN;Status;;Name;;;;;Ports
----;-------;--------------------------------;---------------------------------
1;;;;Static;;Default;;F0/1,;F0/24
2;;;;Static;;VLAN0002;F0/2,;F0/24
3;;;;Static;;VLAN0003;F0/3,;F0/24
4;;;;Static;;VLAN0004;F0/4,;F0/24
5;;;;Static;;VLAN0005;F0/5,;F0/24
6;;;;Static;;VLAN0006;F0/6,;F0/24
7;;;;Static;;VLAN0007;F0/7,;F0/24
8;;;;Static;;VLAN0008;F0/8,;F0/24
9;;;;Static;;VLAN0009;F0/9,;F0/24
10;;;Static;;VLAN0010;F0/10,;F0/24
11;;;Static;;VLAN0011;F0/11,;F0/24
12;;;Static;;VLAN0012;F0/12,;F0/24
13;;;Static;;VLAN0013;F0/13,;F0/24
14;;;Static;;VLAN0014;F0/14,;F0/24
15;;;Static;;VLAN0015;F0/15,;F0/24
16;;;Static;;VLAN0016;F0/16,;F0/24
17;;;Static;;VLAN0017;F0/17,;F0/24
18;;;Static;;VLAN0018;F0/18,;F0/24
19;;;Static;;VLAN0019;F0/19,;F0/24
20;;;Static;;VLAN0020;F0/20,;F0/24
21;;;Static;;VLAN0021;F0/21,;F0/24
22;;;Static;;VLAN0022;F0/22,;F0/24
23;;;Static;;VLAN0023;F0/23,;F0/24
24;;;Static;;VLAN0024;F0/1,;F0/2,;F0/3,;F0/4,;F0/5
F0/6,;F0/7,;F0/8,;F0/9,;F0/10
F0/11,;F0/12,;F0/13,;F0/14,;F0/15
F0/16,;F0/17,;F0/18,;F0/19,;F0/20
F0/21,;F0/22,;F0/23,;F0/24简单分析一下工作流程:
1、f0/2和f0/3之间的通信,
Switch_config#show;vlan;inter;f0/2
Interface;;;;VLAN
Name;Property;PVID;Vlan-Map;uTagg-VLan-Map
--------------------;--------;----;----------------;----------------
FastEthernet0/2;;;;;;Trunk;;;;2;;;;2,24;;;;;2,24
Switch_config#show;vlan;inter;f0/3
Interface;;;;VLAN
Name;Property;PVID;Vlan-Map;uTagg-VLan-Map
--------------------;--------;----;----------------;----------------
FastEthernet0/3;;;;;;Trunk;;;;3;;;;3,24;;;;;3,24
从中我们可以看到,f0/2是属于vlan2和vlan的,且pvid为2,那就是说普通数据(非802.1q)进入这个端口时会被打上tag2,然后zhge报通过交换机到达f0/3时,端口三是指能够untagvlan3和vlan24的的tag的,这个可以从上面的show;vlan;inter;f0/3看出来,所以f0/3无法识别从f0/2过来的数据包!反过来也是一样的!
换句话说就是实现了vlan2和vlan3的隔离!
2、f0/2和f0/24之间的通信,
Switch_config#show;vlan;inter;f0/2
Interface;;;;VLAN
Name;Property;PVID;Vlan-Map;uTagg-VLan-Map
--------------------;--------;----;----------------;----------------
FastEthernet0/2;;;;;;Trunk;;;;2;;;;2,24;;;;;2,24
Switch_config#show;vlan;inter;f0/24
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