802.1q Tunneling

  1. How big is the qnq/encapsulation, 802.1q Tunneling header?
    4 bytes
  2. What should you set the MTU when configuring 802.1q Tunneling?
  3. What are the commands on the PE router to enable 802.1q Tunneling?
    • switchport mode dot1q-tunnel
    • switchport access vlan X
  4. What is Layer 2 Protocol Tunneling used for?
    To tunnel CDP, VTP, STP, PAgP, LACP, and UDLD through a switch.
  5. What are the command to enable Layer 2 Protocol Tunneling for a specific protocol?
    • l2protocol-tunnel [CDP, VTP STP]
    • l2protocol-tunnel point-to-point [LACP, PAgP, UDLD]
  6. When configuring 802.1q tunneling what must be done to prevent leaking of traffic from the customers to the provider?
    vlan dot1q tag native
  7. What is needed when using 802.1q tunneling for etherchannel?
    • On PE Switch:
    • switchport mode dot1q-tunnel on both etherchannel links

    2 different vlans for each linkĀ from etherchannel

    Layer 2 protocol tunneling for the pagp or lacp
Card Set
802.1q Tunneling
802.1q Tunneling, Layer 2 Protocol Tunneling