What is Layer 2 VPN?
Using OSI layer 2 networking protocols, layer 2 VPN is a particular kind of VPN mode. The entire communication from the core VPN infrastructure is forwarded in layer 2 format on a layer 3/IP network and is transformed back to layer 2 mode at the receiving end.
Layer 2 VPN commonly uses MPLS-based labels to transmit data from the transmission site to the destination node via layer 3 or network edge routers. The data is transmitted in layer 3 or IP packet form by the edge router once it chooses the best route. Data is changed back to layer mode if the destination VPN infrastructure uses layer 2 technology. However, conversion is not required if layer 3 mode is used. ISPs and VPN service providers who use layer 2 networking techniques as part of their basic infrastructure frequently use layer 2 VPN. A few of these technologies are frame relay, ATM, and others.
What is Layer 3 VPN?
The OSI layer 3 networking technologies are used to build and offer Layer 3 VPN (L3VPN), a particular sort of VPN mode. Layer 3 virtual routing and forwarding techniques are used to forward every piece of communication coming from the core VPN infrastructure. Another name for a Layer 3 VPN is a virtual private routed network (VPRN).
Main Difference Between L2VPN and L3VPN
The main difference between L2VPN and L3VPN is the layer at which they operate. L2VPN operates at Layer 2 of the OSI model while L3VPN operates at Layer 3. L2VPN is used when the main concern is to extend the reach of an Ethernet LAN while L3VPN is used when the main concern is to connect sites with disparate IP address spaces.
How to Choose Between Layer 2 and Layer 3 VPNs?
When choosing between L2VPN and L3VPN, it is important to consider the specific needs of the network. If extending the reach of an Ethernet LAN is the main concern, then L2VPN is the best option. If connecting sites with disparate IP address spaces is the main concern, then L3VPN should be used.
L3VPNs can offer impenetrable security for peer-to-peer connections, whether they come from suppliers, distant offices, or remote workers. Lower-level versions do not support IPSec protocols, while L3VPNs can, adding an extra layer of protection. But still, if sensitive information needs to be shared between national offices, Layer 2 VPN (L2VPN) can be utilised to connect VLANs.
In general, Layer 2 VPN technologies can be both faster and less expensive than other security options. However, they lack L3VPN’s routing and traffic control capabilities.