Trunk realizes the interworking of the same network segment between different VLAN

Experimental purpose:

The principle of Trunk's treatment of pvid

For Access and Hybrid, pvid is an interface to tag frames without tag, from scratch to existence

For Trunk, if the tag = = pvid in the outward frame, the tag is stripped off, so it is also called the native vlan native VLAN, which is restored to the native frame, the process from being to nothing.

Topology:

Configuration:

SW1 configuration

[sw1] dis cur int g0/0/1

#

Interface GigabitEthernet0/0/1

Port link-type access

Port default vlan 10

#

Return

[sw1] dis cur int g0/0/24

#

Interface GigabitEthernet0/0/24

Port link-type trunk

Port trunk pvid vlan 10

Port trunk allow-pass vlan 10 20

#

Return

SW2 configuration

[sw2] dis cur int g0/0/1

#

Interface GigabitEthernet0/0/1

Port link-type access

Port default vlan 20

#

Return

[sw2] dis cur int g0/0/24

#

Interface GigabitEthernet0/0/24

Port link-type trunk

Port trunk pvid vlan 20

Port trunk allow-pass vlan 10 20

#

Return

Finally, trunk may not be the same for different vendors to deal with pvid. For example, ZTE's trunk does not handle direct forwarding for tag = = pvid.