Edge Device Software Hardware Forwarding Table Packet Routing
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Solution Overview
Problem
In data center networks using VXLAN, conventional methods lead to bandwidth wastage and service interruptions due to broadcast flooding when packets with specific destination IP addresses are not matched in the forwarding table, causing packets to be undeliverable and affecting user experience.
Innovation Solution
A packet transmission method for local edge devices that maintains both software and hardware forwarding tables, where the local edge device receives notification messages to update these tables, allowing it to route packets efficiently through established EVPN neighbors, avoiding broadcast flooding by using the software forwarding table to match and send packets to their correct destinations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If broadcast flooding is used when destination IP address is not matched in forwarding table, then packet delivery coverage is improved, but bandwidth is wasted and service interruptions occur
Solution Approach 1:
The patent maintains a software forwarding table in advance that stores mapping relationships between destination IP addresses and corresponding VLAN IDs. When a packet arrives, the system performs preliminary matching against this pre-established software forwarding table before attempting hardware table lookup, enabling proactive identification of packets requiring cross-VLAN routing and preventing unnecessary broadcast flooding.
Solution Approach 2:
The patent introduces a software forwarding table as an intermediary layer between the hardware forwarding table and the broadcast flooding mechanism. This intermediate software table acts as a buffer that captures packets needing special handling (cross-VLAN routing), allowing the system to avoid direct broadcast flooding while maintaining reliable packet delivery through software-based routing.
2Measurement precision
If software forwarding table is queried for every packet, then packet routing accuracy is improved, but processing time increases
Solution Approach 1:
The patent segments the forwarding table into two distinct layers: a hardware forwarding table for fast, common-case packet forwarding and a software forwarding table for accurate, cross-VLAN packet routing. This segmentation allows the system to use the lightweight hardware table for the majority of packets, reserving software table queries only for packets requiring cross-VLAN routing, thereby minimizing processing time overhead while maintaining routing accuracy.
Solution Approach 2:
Instead of querying the software forwarding table for every packet (excessive action), the patent applies partial action by first checking the hardware forwarding table and only querying the software table when the hardware table indicates a miss or when cross-VLAN routing is detected. This partial approach reduces processing time while maintaining sufficient routing accuracy for the specific use case of cross-VLAN packet forwarding.
Data Source
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AI summary
A packet-transmission method, a local edge device and a machine-readable storage medium are provided. The method includes: receiving a first notification message from an opposite edge device, parsing out a first host route from the first notification message, and adding a first forwarding table entry to a software forwarding table, wherein the first forwarding table entry includes a correspondence between the first host route and an interface receiving the first notification message; inquiring, after receiving a packet, a hardware forwarding table according to a destination address of the packet, if there is no forwarding table entry matched with the destination address in the hardware forwarding table, inquiring the software forwarding table according to the destination address of the packet, if there is a forwarding table entry matched with the destination address in the software forwarding table, sending the packet according to the forwarding table entry matched with the destination address. With the technical solutions of the present disclosure, broadcasting of this packet in the data center of the local edge device is avoided, saving the bandwidth resource of the data center, avoiding interruption of the service of the host, and improving the user's using experience.