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Trunk Configuration: Why configure a port with switchport access VLAN XX and switchport mode trunk

Steph1963
Level 1
Level 1

Hi to All,

I was looking at the Cisco TSHOOT demo on line and I notice that their trunk port was configure as access and trunk.

vlan 10
name CLIENT_VLAN
!
vlan 98
name NATIVE_VLAN
!
vlan 99
namae PARKING_LOT

interface FastEthernet1/0/19
description Trunk to ASW1
switchport access vlan 99
switchport trunk encapsulation dot1q
switchport trunk native vlan 98
switchport trunk allowed vlan 10,98
switchport mode trunk

1) Does anybody knows the reason behind defining a single port with switchport access vlan 99 and switchport mode trunk at the same time.

2) The following show interface switchport displays an Access mode VLAN: 99 (PARKING_LOT). How can we utilize this access mode, it seems to me that native traffic will be encapsulated in VLAN 98? Do not understand when this can be used

show interface FastEthernet1/0/19 switchport
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: trunk
Administrative Trunking Encapsulation: dot1q
Negotiation of Trunking: On
Access Mode VLAN: 99 (PARKING_LOT)
Trunking Native Mode VLAN:98 (NATIVE_VLAN)
Administrative Native VLAN tagging: enable
Voice VLAN: none
Administrative private-vlan host hos-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk associations: none
Administrative private-vlan trunk mappings: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Capture Mode Disabled

Thanks for your help

Stéphane

1 Reply 1

Edison Ortiz
Hall of Fame
Hall of Fame

) Does anybody knows the reason behind defining a single port with  switchport access vlan 99 and switchport mode trunk at the same time.

It could be old configuration left behind.

Per your outputs, the port is running in trunk mode and its native Vlan is 98, not 99.

Therefore, a workstation or any device not running a trunking protocol will reside on Vlan 98.

The following show interface switchport displays an Access mode VLAN: 99  (PARKING_LOT). How can we utilize this access mode, it seems to me that  native traffic will be encapsulated in VLAN 98? Do not understand when  this can be used

The only way to utilize this mode is to change it to access.

Regards,

Edison