What is Dot1q tunneling?

802.1Q tunneling enables Service Providers to use a single VLAN to support customers who have multiple VLANs, while preserving customer VLAN IDs and keeping traffic in different customer VLANs segregated. A port configured to support 802.1Q tunneling is called a tunnel port.

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 QinQ Tunnelling?

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.

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 in an Ethernet frame; together these tags constitute a tag stack.

What is Cvlan and Svlan?

CVLAN tag—Identifies the VLAN to which the frame belongs when it is transmitted in the customer network. SVLAN tag—Identifies the VLAN to which the QinQ frame belongs when it is transmitted in the service provider network. The service provider allocates the SVLAN tag to the customer.

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 a dot1q trunk?

VLAN Trunking (802.1Q) allows physical network interfaces in a computing environment to be shared, or multi-homed. Network devices on the network then only interact with packets that have the correct tags. This allows multiple different logical networks to run on the same cable and switch infrastructure.

What is dot1q Cisco?

802.1q (also known as dot1q) is an IEEE industry standard trunking protocol. Cisco switches supports both ISL (Inter Switch Link – Cisco propietory) and 802.1q. 802.1Q-compliant switch ports can be configured to transmit tagged or untagged frames.

What is Svlan and Cvlan?

What is second dot1q?

Router(config-subif)# encapsulation dot1q 100 second-dot1q 200. (Required) Enables the 802.1Q encapsulation of traffic on a specified subinterface in a VLAN. • Use the second-dot1q keyword and the vlan-id argument to specify the VLAN tags to be terminated on the subinterface.

What is 0x8100 EtherType?

0x8100 is standard ethertype for single tagged frames (802.1Q), it can be used(and it is) for QinQ tunneling but you should be careful with other vendors configuration, as defaults vary.

What is C tag and S-tag?

C-Tag is an abbreviation of Customer VLAN tag. In this double tagging, the C-Tag (customer tag) is the inner tag set by the customer. The S-Tag is the outer tag next to the MAC address.

How does Q-in-Q tunneling work in Juniper Networks?

The Juniper Networks Junos operating system (Junos OS) implementation of Q-in-Q tunneling supports the IEEE 802.1ad standard. In Q-in-Q tunneling, as a packet travels from a customer VLAN (C-VLAN) to a service provider’s VLAN, a customer-specific 802.1Q tag is added to the packet.

What is Cisco Q-in-Q tunneling (Dot1q)?

This article describes how to configure an EX Series switch with Cisco Q-in-Q tunneling. 802.1Q (dot1Q) tunneling (Q-in-Q) is commonly used by service providers on metro Ethernet access networks. The protocol extensions are defined in IEEE 802.1ad.

What is Dot1q protocol extension?

The protocol extensions are defined in IEEE 802.1ad. A “service” dot1Q tag is used on the service provider network to segregate traffic into different VLANs defined by the service provider.

Does Junos OS support Q-in-Q tunneling?

The Junos OS software implementation of Q-in-Q tunneling supports the IEEE 802.1ad standard. The following example outlines a Q-in-Q topology and configuration. Customer tagged traffic comes in on ge-0/0/1 and ge-0/0/3, and is sent across ge-0/0/4 (cloud) preserved, and ge-0/0/15 gets the tagged traffic.