Voice VLAN Lab 配置举例

r1-1(e0/0)-----(f0/1)sw(f0/2)---------r1-2(f0/0)
　　 |
　　 (f0/3)----------r1-3(e0)
　　
　　cat3550 f0/2 configured with one access vlan 20 and
　　one voice vlan 50
　　 f0/1 access vlan 50
　　 f0/3 access vlan 20
　　
　　r1-2 configured with a native vlan 20 and a dot1q
　　trunk vlan 50 (simulating ip phone)
　　
　　And ping r1-1 and r1-3 works from r1-2!
　　
　　This means that cat3550 treats the voice vlan in a
　　very special way!
　　
　　If you configure the voice vlan port as a dot1q trunk
　　port, you may need
　　to block all vlans other than the native vlan and
　　voice vlan. Otherwise
　　all other vlan packets will be sent to the ip phone...
　　
　　===================================
　　cat3550 configuration:
　　
　　interface FastEthernet0/1
　　 switchport access vlan 50
　　 no ip address
　　!
　　interface FastEthernet0/2
　　 switchport access vlan 20
　　 switchport voice vlan 50
　　 no ip address
　　 duplex full
　　 speed 100
　　 spanning-tree portfast
　　!
　　interface FastEthernet0/3
　　 switchport access vlan 20
　　 no ip address
　　!
　　=============
　　
　　r1-1:
　　interface Ethernet0/0
　　 ip address 50.1.1.10 255.255.255.0
　　
　　r1-2:
　　
　　interface FastEthernet0/0
　　 no ip address
　　 speed 100
　　 full-duplex
　　!
　　interface FastEthernet0/0.20
　　 encapsulation dot1Q 20 native
　　 ip address 20.1.1.1 255.255.255.0
　　!
　　interface FastEthernet0/0.50
　　 encapsulation dot1Q 50
　　 ip address 50.1.1.1 255.255.255.0
　　!
　　
　　
　　r1-3:
　　interface Ethernet0
　　 ip address 20.1.1.3 255.255.255.0
　　 no ip directed-broadcast
　　!
　　
　　r1-2#p 20.1.1.3
　　
　　Type escape sequence to abort.
　　Sending 5, 100-byte ICMP Echos to 20.1.1.3, timeout is
　　2 seconds:
　　!!!!!
　　Success rate is 100 percent (5/5), round-trip
　　min/avg/max = 1/2/4 ms
　　
　　r1-2#p 50.1.1.10
　　
　　Type escape sequence to abort.
　　Sending 5, 100-byte ICMP Echos to 50.1.1.10, timeout
　　is 2 seconds:
　　!!!!!
　　Success rate is 100 percent (5/5), round-trip
　　min/avg/max = 1/2/4 ms
　　
　　cat3550-11#sh int f0/2 swi
　　Name: Fa0/2
　　Switchport: Enabled
　　Administrative Mode: dynamic desirable
　　Operational Mode: static access
　　Administrative Trunking Encapsulation: negotiate
　　Operational Trunking Encapsulation: native
　　Negotiation of Trunking: On
　　Access Mode VLAN: 20 (VLAN0020)
　　Trunking Native Mode VLAN: 1 (default)
　　Administrative private-vlan host-association: none
　　Administrative private-vlan mapping: none
　　Operational private-vlan: none
　　Trunking VLANs Enabled: ALL
　　Pruning VLANs Enabled: 2-1001
　　
　　Protected: false
　　Unknown unicast blocked: disabled
　　Unknown multicast blocked: disabled
　　
　　
　　Voice VLAN: 50 (VLAN0050) <--- wow, voice vlan now is