What is QinQ Cisco?

A Q-in-Q VLAN tunnel enables a service provider to segregate the traffic of different customers in their infrastructure, while still giving the customer a full range of VLANs for their internal use by adding a second 802.1Q tag to an already tagged frame.

What is the difference between QinQ and DOT1Q?

The original 802.1Q specification allows a single Virtual Local Area Network (VLAN) header to be inserted into an Ethernet frame. QinQ allows multiple VLAN tags to be inserted into a single frame, an essential capability for implementing Metro Ethernet network topologies.

What is encapsulation DOT1Q command?

The switchport trunk encapsulation dot1q command tells the switch that the interface should use IEEE 802.1Q encapsulation on the frames when the interface is configured as a trunk. Basically 802.1Q inserts a VLAN tag on the frames. This contrasts with ISL that actually encapsulates the frames with an ISL frame.

How do I configure QinQ?

To configure the switch, follow these steps:

  1. Enable QinQ: Edge l(config)#: qinq svlan tag-type 88a8.
  2. Reboot the box with the configuration saved to transfer into svlan bridge mode.
  3. Configure S-VLANs and ports connected to the customer network.
  4. Configure the provider ports leading to the core of the provider network.

What is ISL and dot1q?

ISL and DOT1Q are 2 encapsulation standards supporting Virtual LANs (VLANs) on an Ethernet network. These are the 2 frame tagging protocols that Cisco supports. The tagging protocol can be manually specified on a trunk port, or dynamically negotiated using Cisco’s proprietary Dynamic Trunking Protocol (DTP).

Is 802.1Q the same as dot1q?

IEEE 802.1Q, often referred to as Dot1q, is the networking standard that supports virtual LANs (VLANs) on an IEEE 802.3 Ethernet network. The standard defines a system of VLAN tagging for Ethernet frames and the accompanying procedures to be used by bridges and switches in handling such frames.

What is encapsulation dot1q in Cisco?

IEEE 802.1Q encapsulation is configurable on Ethernet and EtherChannel interfaces. IEEE 802.1Q is a standard protocol for interconnecting multiple switches and routers and for defining VLAN topologies. Use the encapsulation dot1q command in subinterface range configuration mode to apply a VLAN ID to the subinterface.

What is QinQ tunneling?

802.1Q tunneling (aka Q-in-Q) is a technique often used by Metro Ethernet providers as a layer 2 VPN for customers. By using a different VLAN tag for each customer we can separate the traffic from different customers and also transparently transfer it throughout the service provider network.

Why is QinQ used?

The general purpose of QinQ is to allow frames from multiple customers to be forwarded (or tunneled) through another topology (provider network) using service VLANs or S-VLANs.

What is QinQ Tunnelling?