QinQ tagging

Taking a look at QinQ technologies. Had to work with a cloud provider that leveraged this technology and wanted to take a look at what the heck QinQ was under the hood. After labing this one up there isn’t much to it and it reminds me of “VLAN hopping”, an old security issue I remember reading up on during my Certified Ethical Hacker studies years ago.

Topology

…show me the config

conf t
!
vlan 3000
 name customer XYZ
!
int g0/1
switch access vlan 3000
switch mode dot1q-tunnel

conf t
!
vlan 3000
 name customer XYZ
!
int g0/1
switch access vlan 3000
switch mode dot1q-tunnel

conf t
!
vlan 3000
 name customer XYZ
!
int g0/1
switch access vlan 3000
switch mode dot1q-tunnel

conf t
!
vlan 3000
 name customer XYZ
!
int g0/1
switch access vlan 3000
switch mode dot1q-tunnel