Host Routing for VM Mobility with Proxy ARP and EVPN Type-5 Routes
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Solution Overview
Problem
Conventional Ethernet virtual private network (EVPN) integrated routing and bridging (IRB) networking schemes require network devices to store the MAC addresses of all VMs, leading to scalability and mobility issues when dealing with thousands to hundreds of thousands of VMs.
Innovation Solution
Implementing a method that combines features of type-2 and type-5 routes, utilizing proxy ARP for VM identification and incorporating IP mobility extensions, allowing network traffic to be routed rather than bridged, and using unicast reverse path forwarding to manage VM mobility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If network devices store MAC addresses of all VMs in network address tables for EVPN IRB networking, then network traffic can be bridged between VMs, but scalability deteriorates when dealing with thousands to hundreds of thousands of VMs
Solution Approach 1:
The patent extracts the MAC address storage requirement from the network address tables by introducing type-5 EVPN routes that carry VM mobility information. Instead of storing all VM MAC addresses in L2 tables, the system uses L3 routing tables with type-5 routes to track VM locations, thereby removing the scalability bottleneck while preserving bridging functionality through proxy ARP.
Solution Approach 2:
The patent introduces proxy ARP as an intermediary mechanism between L2 bridging and L3 routing. Proxy ARP allows VMs to resolve each other's MAC addresses through ARP requests routed via type-5 routes, enabling VM communication without requiring network devices to maintain complete MAC address tables of all VMs, thus achieving both bridging and scalability.
2Reliability
If network devices program MAC addresses of all VMs in network address tables, then VM communication is enabled, but extensive reprogramming is required during VM moves
Solution Approach 1:
The patent implements dynamic VM mobility support through type-5 EVPN routes that automatically update when VMs move between network devices. The routing table entries with type-5 routes are dynamically modified to reflect new VM locations, eliminating the need for extensive manual reprogramming and reducing mobility disruption time.
Solution Approach 2:
The patent prepares for VM mobility by pre-configuring type-5 routes with mobility information before VM moves occur. This preliminary setup allows the network to quickly adapt to VM relocations through automated route updates, minimizing the reprogramming time and disruption during VM mobility events.
3Reliability
If network address tables include MAC addresses of all VMs, then complete network connectivity is achieved, but hardware storage resources are excessively consumed
Solution Approach 1:
The patent extracts the essential connectivity information from complete MAC address tables by using type-5 EVPN routes that store only necessary routing information. This extraction reduces the storage requirement from storing all VM MAC addresses to storing only the routing table entries with mobility information, significantly conserving hardware storage resources while maintaining network connectivity.
Data Source
AI summary
A method for supporting virtual machine (VM) mobility between network devices connected to a network includes: selecting a first type of route for interconnecting VMs that are connected to the network devices; and adding a feature of a second type of route to the first type of route to enable the network devices to execute proxy address resolution protocol (ARP) for transmitting network traffic between the VMs without requiring each of the network devices to store a physical address of each of the VMs in respective ones of a network address table.