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GRE over EVPN-VXLAN

GRE over EVPN-VXLAN enables encapsulation and de-encapsulation of GRE packets within VXLAN tunnels. This protects inner traffic from exposure to intermediate devices during traversal across network segments.

The integration of Generic Routing Encapsulation (GRE) over EVPN-VXLAN Type 2 tunnels on Junos OS Evolved leverages the forwarding ASIC to encapsulate and de-encapsulate GRE packets. This functionality ensures that GRE frames from remote locations can be efficiently transported through data center networks utilizing EVPN-VXLAN. Support for GRE encapsulation and de-encapsulation, along with configurations such as the "tunnel-loopback" option under Integrated Routing and Bridging (IRB) in the VXLAN bridge domain, enhances the flexibility and performance of complex tunneling setups. Additionally, it includes specific operational parameters and limitations, such as the support for IPv4 underlay only and a maximum throughput of 400 Gbps per DLB (Dynamic Load Balancing) port due to the loopback requirements.

Benefits of GRE over EVPN-VXLAN Support

  • Enhances network flexibility by supporting complex tunneling scenarios, accommodating diverse customer use cases and improving overall data traffic management.

  • Enhances security by encapsulating GRE traffic within VXLAN tunnels. This provides an additional layer of security by isolating customer traffic from external devices and potential threats.

  • Improves traffic handling efficiency by utilizing the forwarding ASIC for GRE encapsulation and de-encapsulation, ensuring high performance in data center network environments.

  • Simplifies configuration and implementation with the use of existing EVPN-VXLAN and GRE settings, minimizing the need for new commands or extensive reconfiguration.

Overview

When you implement GRE over EVPN-VXLAN on the Junos OS Evolved platform, you leverage the forwarding ASIC to encapsulate and de-encapsulate GRE packets within VXLAN tunnels. This functionality is essential for ensuring secure and efficient traversal of customer traffic across different network segments. To configure this feature, you will primarily use the tunnel-loopback option under IRB interfaces. This configuration allows GRE packets to be looped back for encapsulation within VXLAN, and upon reaching the destination, VXLAN headers are de-encapsulated first, followed by the GRE headers. This ensures that the internal traffic remains hidden from intermediate devices, maintaining its integrity and preventing double-billing issues for ISP customers.

To configure GRE over EVPN-VXLAN, you will use existing Junos OS Evolved CLI commands for EVPN-VXLAN and GRE, ensuring a streamlined configuration process. Key configuration steps include setting up the IRB interfaces with the tunnel-loopback statement. For example, you would use commands like set interfaces irb unit name family inet tunnel-loopback to enable the tunnel-loopback functionality. Additionally, you need to configure the appropriate routing instances and protocol settings to ensure proper encapsulation and de-encapsulation of traffic. This setup is critical for maintaining the operational efficiency and security of network traffic across multiple segments.

While this feature offers significant benefits, it is crucial to understand its limitations. GRE over EVPN-VXLAN requires a loopback pass for both encapsulation and de-encapsulation, which limits the overall throughput per DLB port. Additionally, it does not support VXLAN Type 5 tunnels, bypass-loopback options configured under the flexible tunnel interface for GRE, or filter-based de-encapsulation for GRE. GRE over EVPN-VXLAN support is also limited to an IPv4 underlay only. Despite these limitations, this feature enhances the flexibility and scalability of network designs, ensuring secure and efficient traffic traversal.

Please refer to Feature Explorer for a complete list of the products that support this feature.

Configuration Example

This example illustrates an ISP using GRE over VXLAN.

Related Documentation