Virtual Bridge ARP Interception for IP Reuse in Data Centers

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Solution Overview

Problem

In network data centers, managing multiple virtual machines from different corporations with the same private IP address range is challenging, as existing systems require exclusive IP addresses for correct packet forwarding, leading to increased costs and complexity.

Innovation Solution

A data center network system that uses a virtual bridge and ARP server to intercept ARP requests, add a VDCID to the identification field, and query the corresponding MAC address based on the IP address and VDCID, allowing the same private IP address to be reused across virtual machines within the same virtual data center.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If exclusive IP addresses are assigned to each virtual machine for correct packet forwarding, then packet forwarding accuracy is improved, but network management complexity and cost increase

Engineering Contradiction:

Improvepacket forwarding accuracyVSAvoidnetwork management complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the network identification space by introducing VDCID as an additional dimension. Instead of relying solely on IP addresses, the system divides virtual machines into different VDCs (Virtual Data Centers) identified by VDCID. This segmentation allows IP address reuse within each VDC while maintaining global uniqueness across the network, reducing the need for exclusive IP addresses and simplifying network management.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces VDCID as an intermediary identifier between the IP address and the virtual machine. The extended ARP request mechanism uses VDCID as a mediator to disambiguate IP addresses that are reused across different VDCs. This intermediary layer enables correct packet forwarding without requiring unique IP addresses for each virtual machine, thereby reducing network management complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If exclusive IP addresses are assigned to each virtual machine, then packet forwarding correctness is improved, but IP address resource consumption increases

Engineering Contradiction:

Improvepacket forwarding correctnessVSAvoidIP address resources

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The network space is segmented into multiple VDCs, each with its own VDCID. Within each VDC, IP addresses can be reused from a common pool. This segmentation enables the same IP address range to be allocated to multiple VDCs simultaneously, significantly reducing the total number of unique IP addresses required while maintaining correct packet forwarding through VDCID disambiguation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the identification parameters from just IP address to a combination of IP address and VDCID. This parameter change allows the system to distinguish between virtual machines with the same IP address by using the additional VDCID parameter, thereby enabling IP address reuse and reducing overall IP address resource consumption.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If same private IP address is reused across virtual machines in the same data center network, then IP address resource efficiency is improved, but packet forwarding accuracy deteriorates without additional identification mechanisms

Engineering Contradiction:

ImproveIP address resource efficiencyVSAvoidpacket forwarding accuracy

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent adds another dimension (VDCID) to the IP address identification space. Instead of relying on a single-dimensional IP address, the system uses a two-dimensional identification scheme combining IP address and VDCID. This dimensional extension allows the same IP address to be reused across different VDCs while maintaining unique identification and accurate packet forwarding.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

VDCID serves as an intermediary identifier that resolves the ambiguity caused by IP address reuse. The extended ARP request mechanism incorporates VDCID as a mediator to correctly identify the target virtual machine when multiple virtual machines share the same IP address across different VDCs, thereby maintaining packet forwarding accuracy while enabling IP address reuse.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS8767737B2Data center network system and packet forwarding method thereof

Publication Date: 2014.07.01 IND TECH RES INST

AI summary

A data center network system and a packet forwarding method thereof are provided. The data center network system includes a virtual bridge and an address resolution protocol (ARP) server. The virtual bridge intercepts an ARP request having an identification field and a destination IP address field and adds a corresponding virtual data center identification to the identification field of the ARP request and redirecting the ARP request to the ARP server. Additionally, the ARP server queries a corresponding MAC address according to an IP address recorded in the destination IP address field of the ARP request and the corresponding VDCID recorded in the identification field of the ARP request, and transmits the corresponding MAC address in response to the ARP request. Accordingly, the same private IP address can be reused in the data center network system.