Browse Prior Art Database

Load Balancing Method of BGP Path

IP.com Disclosure Number: IPCOM000193898D
Publication Date: 2010-Mar-12
Document File: 3 page(s) / 197K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method of BGP path load balancing.

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Load Balancing Method of BGP Path

1. Background
- BGP (Boarder Gateway Protocol) is one of IP routing protocol.
- BGP is mainly used in the Internet between AS, however it can be in private enterprise network.
- When using BGP in enterprise network, load balancing between multiple paths is often required.
- There are three methods that make load balanced paths enable on BGP. - eBGP multi-path

     Load balancing between multiple eBGP paths - iBGP multi-path

     Load balancing between multiple iBGP paths - eiBGP multi-path

Load balancing between eBGP and iBGP paths

2. eiBGP multi-path

   Redistribute route of terminal A to OSPF

Load balancing: per session

BGP AS Path:
x, y0, z BGP AS Path:

x, y1, z

Datacenter A Datacenter B

Server

Terminal A Blanch

VRF

OSPF OSPF iBGP

eBGP eBGP

eBGP eBGP

Rc0

Rc2

R

R

Rc1

Rc3

BGP AS x

BGP AS y0 BGP AS y1

BGP AS z

OSPF area 0

  Left path traverses only on eBGP sections, although right path does on iBGP and eBGP.

Rg0

Rg1

Rb0

Rb1

OSPF

R

R

Router

3. Problem to be solved
- eiBGP multi-path is implemented only on VRF (Virtual router forwarding). e.x. Cisco IOS
- VRF is a sub function of MPLS, therefore VRF is not used in a normal configuration.

- How can eiBGP or same function can be implemented without using VRF

4. False Solution

1

Page 2 of 3

   Redistribute route of terminal A to OSPF ?
at Cost: 100

Datacenter A Datacenter B

OSPF OSPF iBGP

eBGP eBGP

               eBGP eBGP
BGP AS Path:
x, y0, z BGP AS Path:

x, y1, z

Rc0

Rc2

Server

Cost:100

R

R

Rc1

Rc3

BGP AS x

BGP AS y0 BGP AS y1

BGP AS z

   Redistribute route of terminal A to OSPF
at Cost: 100

OSPF area 0

  Path cost of left and right paths from the Server is the same, that seems to make load balancing available.

  However, the route can not be redistributed from Rc0, since Rc0 does not have eBGP best path

Rg0

Rg1

Rb0

Rb1

OSPF

R

Terminal A

5. Sound Solution

Datacenter A Datacenter B

   Redistribute route of term inal A to O SPF at

Cost 100

VRF

O SPF Cost: 100

O SPF O SPF...