5.3 VLAN间通信

1.基本概念

不同VLAN之间无法进行二层通信，如果需要通信，需要三层设备（功能）来实现通信。

1）通过路由器接口实现VLAN间通信

[R1]interface GigabitEthernet 0/0/0
[R1-GigabitEthernet0/0/0]ip address 192.168.10.254 24
[R1]interface GigabitEthernet 0/0/1
[R1-GigabitEthernet0/0/1]ip address 192.168.20.254 24

[sw1]vlan batch 10 20
[sw1]interface GigabitEthernet 0/0/1
[sw1-GigabitEthernet0/0/1]port link-type access 
[sw1-GigabitEthernet0/0/1]port default vlan 10

[sw1]interface GigabitEthernet 0/0/2
[sw1-GigabitEthernet0/0/2]port link-type access 
[sw1-GigabitEthernet0/0/2]port default vlan 20

[sw1]interface GigabitEthernet 0/0/23
[sw1-GigabitEthernet0/0/23]port link-type access 
[sw1-GigabitEthernet0/0/23]port default vlan 20

[sw1]interface GigabitEthernet 0/0/24
[sw1-GigabitEthernet0/0/24]port link-type access 
[sw1-GigabitEthernet0/0/24]port default vlan 10

PC1>ping 192.168.20.1

From 192.168.20.1: bytes=32 seq=5 ttl=127 time=62 ms

PC1>tracert 192.168.20.1
traceroute to 192.168.20.1, 8 hops max
(ICMP), press Ctrl+C to stop
 1  192.168.10.254   63 ms  31 ms  47 ms
 2  192.168.20.1   94 ms  78 ms  94 ms

2）通过路由器子接口实现VLAN间通信

（1）SW1配置

[sw1]vlan batch 10 20
[sw1]interface GigabitEthernet 0/0/1
[sw1-GigabitEthernet0/0/1]port link-type access 
[sw1-GigabitEthernet0/0/1]port default vlan 10

[sw1]interface GigabitEthernet 0/0/2
[sw1-GigabitEthernet0/0/2]port link-type access 
[sw1-GigabitEthernet0/0/2]port default vlan 20

[sw1]interface GigabitEthernet 0/0/24
[sw1-GigabitEthernet0/0/24]port link-type trunk 
[sw1-GigabitEthernet0/0/24]port trunk allow-pass vlan 10 20

（2）R1配置

[R1]interface GigabitEthernet 0/0/0.10
[R1-GigabitEthernet0/0/0.10]ip address 192.168.10.254 24
[R1-GigabitEthernet0/0/0.10]dot1q termination vid 10
[R1-GigabitEthernet0/0/0.10]arp broadcast enable 

[R1]interface GigabitEthernet 0/0/0.20
[R1-GigabitEthernet0/0/0.2]ip address 192.168.20.254 24
[R1-GigabitEthernet0/0/0.20]dot1q termination vid 20
[R1-GigabitEthernet0/0/0.20]arp broadcast enable 

PC1>ping 192.168.20.1
Ping 192.168.20.1: 32 data bytes, Press Ctrl_C to break
PC1>tracert 192.168.20.1
traceroute to 192.168.20.1, 8 hops max
(ICMP), press Ctrl+C to stop
 1  192.168.10.254   31 ms  31 ms  47 ms
 2  192.168.20.1   78 ms  94 ms  78 ms

3）使用 VLANIF实现VLAN间通信

（1）SW1配置

[sw1]vlan batch 10 20
[sw1]interface GigabitEthernet 0/0/1
[sw1-GigabitEthernet0/0/1]port link-type access 
[sw1-GigabitEthernet0/0/1]port default vlan 10

[sw1]interface GigabitEthernet 0/0/2
[sw1-GigabitEthernet0/0/2]port link-type access 
[sw1-GigabitEthernet0/0/2]port default vlan 20

[sw1]interface GigabitEthernet 0/0/24
[sw1-GigabitEthernet0/0/24]port link-type trunk 
[sw1-GigabitEthernet0/0/24]port trunk allow-pass vlan 10 20

（2）SW2配置

[SW2]vlan batch 10 20 100
[SW2]interface GigabitEthernet 0/0/24
[SW2-GigabitEthernet0/0/24]port link-type trunk 
[SW2-GigabitEthernet0/0/24]port trunk allow-pass vlan 10 20
[SW2]interface GigabitEthernet 0/0/23
[SW2-GigabitEthernet0/0/23]port link-type access 
[SW2-GigabitEthernet0/0/23]port default vlan 100

[SW2]interface Vlanif 10
[SW2-Vlanif10]ip address 192.168.10.254 24
[SW2-Vlanif10]quit
[SW2]interface Vlanif 20
[SW2-Vlanif20]ip address 192.168.20.254 24
[SW2]interface Vlanif 100
[SW2-Vlanif100]ip address 192.168.100.253 24
[SW2]ip route-static 0.0.0.0 0.0.0.0 192.168.100.254

（3）R1配置

[R1]interface GigabitEthernet 0/0/0
[R1-GigabitEthernet0/0/0]ip address 192.168.100.254 24
[R1]interface GigabitEthernet 0/0/1 
[R1-GigabitEthernet0/0/1]ip address 192.168.1.254 24
[R1]ip route-static 192.168.10.0 24 192.168.100.253 
[R1]ip route-static 192.168.20.0 24 192.168.100.253

（4）查看SW2路由表

[SW2]display ip routing-table
Destination/Mask    Proto   Pre  Cost      Flags NextHop         Interface
0.0.0.0/0   Static  60   0          RD   192.168.100.254 Vlanif100
127.0.0.0/8   Direct  0    0           D   127.0.0.1       InLoopBack0
127.0.0.1/32  Direct  0    0           D   127.0.0.1       InLoopBack0
192.168.10.0/24  Direct  0    0           D   192.168.10.254  Vlanif10
192.168.10.254/32  Direct  0    0           D   127.0.0.1       Vlanif10
192.168.20.0/24  Direct  0    0           D   192.168.20.254  Vlanif20
192.168.20.254/32  Direct  0    0           D   127.0.0.1       Vlanif20
192.168.100.0/24  Direct  0    0           D   192.168.100.253 Vlanif100
192.168.100.253/32  Direct  0    0           D   127.0.0.1       Vlanif100
PC1>ping 192.168.1.254
From 192.168.1.254: bytes=32 seq=2 ttl=254 time=62 ms

PC1>tracert 192.168.1.1
traceroute to 192.168.1.1, 8 hops max
(ICMP), press Ctrl+C to stop
 1  192.168.10.254   31 ms  47 ms  47 ms
 2  192.168.100.254   62 ms  63 ms  62 ms
 3  192.168.1.1   63 ms  62 ms  63 ms