PE Device Host Route Processing in Virtual Subnets
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In virtual subnets, multiple provider edge (PE) devices can form CE host routing loops, leading to increased data packet forwarding paths and reduced transmission efficiency between customer edge (CE) hosts.
Innovation Solution
A method where a first PE device determines if a source MAC address in a received packet is a virtual MAC address, and if so, skips saving or distributing a local CE host routing table entry or route, preventing the propagation of incorrect routing information and thus avoiding routing loops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If PE devices exchange local CE host routes through L3VPN routing protocol to implement subnet extension, then routing coverage is improved, but routing loops may form and transmission efficiency deteriorates
Solution Approach 1:
The patent applies local quality by making PE devices differentiate their behavior based on local conditions - specifically, whether they have multiple CE hosts locally or single CE host. PE devices with multiple local CE hosts suppress local CE host route advertisements, while those with single local CE hosts continue normal route exchange. This localized adaptation prevents routing loops at specific sites while maintaining subnet extension capability elsewhere.
Solution Approach 2:
The patent introduces an intermediary mechanism - the detection of locally connected CE hosts acting as mediators between routing information exchange and loop prevention. By identifying and suppressing routes to locally connected CE hosts at PE devices, the patent creates an intermediary layer that blocks potential routing loops before they can propagate through the L3VPN routing protocol.
2Loss of information
If PE devices distribute local CE host routes in virtual subnet, then routing information completeness is improved, but forwarding path length increases
Solution Approach 1:
The patent extracts and removes problematic routing information - specifically local CE host routes that cause loops - from the routing distribution process. By selectively suppressing advertisements of local CE host routes at PE devices with multiple local CE hosts, the patent takes out the harmful element while preserving necessary routing information for legitimate subnet extension scenarios.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
Embodiments of the present invention disclose a method for processing a host route in a virtual subnet, a related device and a communications system. The method for processing a host route in the virtual subnet includes: receiving, by a first provider edge device, a packet for address resolution, where a virtual subnet site in which the first provider edge device is located further includes at least one second provider edge device; determining, by the first provider edge device, whether a source MAC address carried in the packet is a virtual MAC address; and when it is determined that the source MAC address is a virtual MAC address, skipping performing at least one of the following operations: saving a local CE host routing table entry corresponding to a source IP address carried in the packet, or distributing, in the virtual subnet based on a routing protocol of a layer 3 VPN, a local CE host route corresponding to the IP address. Technical solutions of the embodiments of the present invention are helpful to avoid forming a CE host routing loop to a greatest extent, further improving efficiency of data packet transmission between CE hosts.