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

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 2

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. SP‘s Backbone for BGP/MPLS VPN PE1 Core Layer Convergence Layer Convergence Layer Access Layer Access Layer PE2 ? PE1 PE2 SP‘s Backbone for BGP/MPLS VPN PE1 and PE2 should maintain the same VPN routes. However, if VPN route table is large, PE2 will have capacity and performance issues. 3

Proposed Solution Proposed Solution Hierarchy of Provider Edge (HoPE) VPN1 Site1 VPN1 Site1 VPN1 Site3 VPN2 Site1 PE UPE1 MP-BGP MPLS network MPLS SPE network VPN1 Site2 VPN2 Site2 VPN2 Site3 UPE2 Hierarchy ofPE PE HoPE supplements RFC2547bis to make it more scalable. 4

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 5

Differences with Multi- -VRF CE VRF CE Differences with Multi Multi-VRF CE HoPE • Requires 1 tunnel, 1 • Requires 1 tunnel, 1 sub-interface, 1 IP sub-interface, 1 IP address, and 1 routing address, and 1 routing instance for each VPN instance for all VPN site sites • Plus PE and CE must • Via ORF mechanism, both configure VRF SPE does not need to configure VRFs VPN1 Site1 already configured in VPN2 Site1 VCE1 UPE MPLS Network PE VPN1 Site2 VPN2 Site2 VCE2 6

Using OSPF between CE/UPE Using OSPF between CE/UPE backdoor link OSPF sham-link OSPF VPN1 Site1 VPN1 Site1 OSPF ------------------------ VPN1 Site3 PE UPE1 MP-BGP MPLS network MPLS SPE network UPE2 Hierarchy ofPE PE • 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 7

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 8