VLAN Trunking 802.1Q

A trunk port carries packets on one or more VLANs specified. A packet that ingresses on a trunk port is in the VLAN specified in its 802.1Q header, or native VLAN if the packet has no 802.1Q header. A packet that egresses through a trunk port will have an 802.1Q header if it has a nonzero VLAN ID. Any packet that ingresses on a trunk port tagged with a VLAN that the port does not trunk is dropped.

Relevant configuration

(switch (config) #) Create a VLAN:

vlan 100

(switch (config vlan 100)#) Exit configuration mode:

exit

(switch (config) #) Enter the interface configuration mode:

interface ethernet 1/35

(switch (config interface ethernet 1/35)#) From within the interface context, configure the interface mode to “hybrid”:

switchport mode hybrid

(switch (config interface ethernet 1/35)#) From within the interface context, configure the allowed VLAN membership:

switchport hybrid allowed-vlan add 100

Expected results

  • Administrators can create and enable multiple VLAN interfaces
  • Administrators can assign the trunk VLAN interfaces

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