VXLAN Packet Forwarding via Virtual Network Identifier
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In VXLAN networks, routing loops occur when multiple VMs sharing a same service IP address are connected to different VXLAN tunnel endpoint devices, leading to incorrect packet forwarding and difficulties in implementing load balancing.
Innovation Solution
A packet forwarding method where a network device receives a packet with a virtual network identifier corresponding to a local virtual machine and forwards it directly based on this identifier, bypassing the VRF table to prevent routing loops and ensure normal forwarding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the network device forwards packets based on VRF table, then routing flexibility is improved, but routing loops occur and packet forwarding reliability deteriorates
Solution Approach 1:
The patent segments the forwarding decision process into two distinct parts: VRF table lookup for initial route selection, and virtual network identifier matching for final packet forwarding. This segmentation prevents routing loops by ensuring that packets destined for local virtual machines are forwarded directly without being redirected to other network devices, thus resolving the contradiction between routing flexibility and forwarding reliability.
Solution Approach 2:
The virtual network identifier acts as an intermediary element that bridges the VRF table routing decision and the actual packet forwarding to virtual machines. By introducing this intermediate matching step, the system maintains routing flexibility through VRF tables while preventing routing loops, as the virtual network identifier explicitly identifies the final destination without requiring further VRF lookups.
2Productivity
If multiple VMs share a same service IP address, then resource utilization is improved, but packet forwarding accuracy deteriorates due to routing loops
Solution Approach 1:
The patent adds another dimension to packet forwarding by introducing virtual network identifier matching alongside the traditional IP address-based VRF table lookup. This dimensional enhancement allows the system to maintain high resource utilization through IP address sharing while achieving accurate packet forwarding, as the virtual network identifier provides an additional discrimination layer that resolves ambiguity among multiple VMs sharing the same IP address.
3Adaptability or versatility
If packets are forwarded through VRF table lookup, then routing adaptability is improved, but forwarding efficiency deteriorates due to additional forwarding hops
Solution Approach 1:
The patent applies preliminary action by performing VRF table lookup once during route establishment, and then using the pre-determined virtual network identifier for subsequent packet forwarding decisions. This preliminary routing decision eliminates the need for repeated VRF table lookups for each packet, thereby maintaining routing adaptability while significantly improving forwarding efficiency by reducing processing hops.
Data Source
Figure 1
Figure 2a
Figure 2b
AI summary
This application provides a packet forwarding method and a network device. The method specifically includes: sending, by a first network device, first routing information to a second network device, where the first routing information is used to advertise a route to a first address of a first virtual machine, and the first routing information includes a first virtual network identifier of the first virtual machine; receiving, by the first network device, a first packet sent by the second network device, where the first packet carries the first virtual network identifier, and a destination address of the first packet is the first address; and forwarding, by the first network device, the first packet to the first virtual machine based on the first virtual network identifier. The first network device forwards the first packet to the corresponding local virtual machine based on the virtual network identifier in the first packet, and does not need to forward the packet according to a virtual routing and forwarding VRF table. This prevents the packet from being forwarded to another network device again, and ensures normal forwarding of the packet.