Hierarchy of Provider Edge Devices in Hierarchy of Provider Edge - - PowerPoint PPT Presentation

Hierarchy of Provider Edge Devices in Hierarchy of Provider Edge Devices in BGP/MPLS VPN BGP/MPLS VPN

<draft-libin-hierarchy-pe-bgp-mpls-vpn-00.txt> Huawei Technologies IETF 56, San Francisco, March 16-21, 2003

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Agenda Agenda

• Problem Overview
• Proposed Solution
• Summary of PPVPN List Discussions

– Differences with RFC2547bis – Differences with Multi-VRF CE – Using OSPF between CE/UPE

• Next Steps

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Problem Overview Problem Overview

Contradiction between “Plane Model Plane Model” in BGP/MPLS VPN model and typical “Layered Architecture Layered Architecture” of SP’s network.

PE1

Core Layer Convergence Layer Convergence Layer Access Layer Access Layer

PE2

SP‘s Backbone for BGP/MPLS VPN

SP‘s Backbone for BGP/MPLS VPN

PE1

PE2

PE1 and PE2 should maintain the same VPN routes. However, if VPN route table is large, PE2 will have capacity and performance issues.

?

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Proposed Solution Proposed Solution

UPE1 UPE2 SPE

VPN1 Site1 VPN1 Site2 VPN2 Site1 VPN2 Site2

MPLS network

Hierarchy ofPE

PE PE

VPN1 Site3 VPN2 Site3 MP-BGP

MPLS network

VPN1 Site1

HoPE supplements RFC2547bis to make it more scalable.

Hierarchy of Provider Edge (HoPE)

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Differences with RFC2547bis Differences with RFC2547bis

• SPE only sends aggregate vpnv4 routes or a

default vpnv4 route to UPE

• Vpnv4 routes are aggregated in SPE. SPE

terminates the LSP from UPE and establishes a new LSP with the remote PE

• UPE advertises its import route target list to SPE.

SPE creates the HoPE-wide import route target list to filter vpnv4 routes from other PEs

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Differences with Multi Differences with Multi-

• VRF CE

VRF CE

Multi-VRF CE

• Requires 1 tunnel, 1

sub-interface, 1 IP address, and 1 routing instance for each VPN site

• Plus PE and CE must

both configure VRF HoPE

• Requires 1 tunnel, 1

sub-interface, 1 IP address, and 1 routing instance for all VPN sites

• Via ORF mechanism,

SPE does not need to configure VRFs already configured in UPE

VCE1 VCE2 PE

VPN1 Site1 VPN1 Site2 VPN2 Site1 VPN2 Site2

MPLS Network

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Using OSPF between CE/UPE Using OSPF between CE/UPE

• If no backdoor links b/w VPN sites, follow standard OSPF procedures
• If backdoor links, create sham-link between HoPE UPE and remote PE
• Then backdoor link may become the preferred link for UPE. To solve:

– Aggregate routes through backdoor at the same granularity and configure metric to make the CE-UPE link the preferred link, or – Have remote PE distribute routes from remote sites to UPE through sham- link and configure a larger metric to backdoor link to make the CE-UPE link the preferred link

UPE1 UPE2 SPE

VPN1 Site1

MPLS network

Hierarchy ofPE

PE PE

VPN1 Site3 MP-BGP

MPLS network

VPN1 Site1

backdoor link OSPF

OSPF OSPF

• sham-link

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Next Steps Next Steps

• Submit ‘01 to I-D and PPVPN mail lists
• Continue discussions on lists and get more

input from interested parties to improve it

• Move forward as a PPVPN WG item
• Incorporate proposal in RFC2547bis or

combine proposal with similar proposals

• Move forward as a Proposed Standard