1 / 13

MVPN PE-PE Signaling

MVPN PE-PE Signaling. IETF 64 Nov 2005 Nidhi Bhaskar/Gargi Nalawade/Pranav Mehta. PE-PE signaling for Multicast VPNs. Multicast VPN PE-PE signaling deployed using PIM LAN procedures Push for replacing PIM with BGP This is an analysis of the BGP enhancements and impact on BGP/PIM.

rianne
Download Presentation

MVPN PE-PE Signaling

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MVPN PE-PE Signaling IETF 64 Nov 2005 Nidhi Bhaskar/Gargi Nalawade/Pranav Mehta

  2. PE-PE signaling for Multicast VPNs • Multicast VPN PE-PE signaling deployed using PIM LAN procedures • Push for replacing PIM with BGP • This is an analysis of the BGP enhancements and impact on BGP/PIM.

  3. Enhancements required in BGP draft-nalawade-l3vpn-mcast-signaling-bgp-00.txt • Multicast PE-PE (Overlay) SAFI NLRI - {RD:G:Flags:S/RP:U-PE:D-PE} • RT/RD Import/Export • Filtering • PIM/BGP Interaction • Inter-AS • New functions in BGP like aggregating D-PE, U-PE based filtering, RPF lookup on ASBR and probably others. No extensions for Unicast Reachability. Rely on existing VPNv4 Unicast for that.

  4. CE-2 CE-4 Receiver1 Source = 1.1.1.1 RR BGP State: RD:232.1.1.1:SPT:1.1.1.1:PE-4:PE-2 RD:232.1.1.1:SPT:1.1.1.1:PE-4:PE-3 RD:232.1.1.1:SPT:1.1.1.1:PE-4:Label200… Transit for VPN SSM - BGP PE-2 BGP State: RD:232.1.1.1:SPT:1.1.1.1:PE-4:PE-2 RD:232.1.1.1:SPT:1.1.1.1:PE-4:Label200… PE-4 BGP State: RD:232.1.1.1:SPT:1.1.1.1:PE-4:PE-2 RD:232.1.1.1:SPT:1.1.1.1:PE-4:PE-3 RD:232.1.1.1:SPT:1.1.1.1:PE-4:Label200… RR PE-1 PIM-V4 VRF JOIN:1.1.1.1,232.1.1.1 e0 e1 PIM-V4 VRF JOIN:1.1.1.1, 232.1.1.1 PE-2 PE-4 PE-3 PE-3 BGP State: RD:232.1.1.1:SPT:1.1.1.1:PE-4:PE-3 RD:232.1.1.1:SPT:1.1.1.1:PE-4:Label200… e0 CE-3 Receiver2

  5. PE-2 Unicast imports reachability for 1.1.1.1 into Red and Blue VRF. When host 1.1.1.1 joins towards 2.2.2.2 ->We don’t want join imported into both Red and Blue table. CE-Y CE-X Source=2.2.2.2 Host = 1.1.1.1 BGP- Issue w/ Re-using unicast RTs PE-2 Red VRF: RD2 Import RT: RT1 Export RT: RT2 Blue VRF: RD3 Import RT:RT1 Export RT:RT3 P PE-1 Red VRF: RD1 Import RT:RT2 Export RT:RT1 e0 e1 PE-2 PE-1 PE-3 e0 CE-Z Receiver2

  6. ABSR Exchange VPNv4 Routes - Option B Update Sent to PE1: PE1:G:SSM:S:ASBR1 Update Sent to ASBR1: ASBR1:G:SSM:S:Label100:FEC-Y Update sent to ASBR2: ASBR2:G:SSM:S:PE2 Update sent to PE2: ASBR2:G:SSM:S:Label20:FEC-X vpnv4 RD:S NH=PE1 vpnv4 RD:S NH=ASBR1 ASBR2 Update to ASBR1: ASBR1:G:SSM:S:ASBR2:Label10 vpnv4 RD:S NH=ASBR2 ASBR1 ASBR2 PE1 AS 2 PE2 AS 1 next-hop-self towards iBGP neighbors CE1 CE2 CE3 CE4 S

  7. BGP - Multicast Routing State • RR Stores 1 multicast route as N*NLRI where N is #of D-Pes interested in stream. And stores all mroutes in the AS. • If there are “N” messages/minute on “M” PEs, RR processes “N*M” messages/minute. • Multicast J/P or route change frequency is different from unicast. Potential load on RR processing a large number of multicast route changes. • Filtering semantics required to meet the MVPN requirements fundamentally different from filtering techniques available in BGP today

  8. BGP - Multicast Routing State (contd) • PIM today uses already converged routing state established by unicast routing • Putting PIM Join/Prune in BGP requires PIM Join/Prune to be routed as a BGP NLRI • This has latency implications on PIM • Potential load on RR has further implications for multicast.

  9. BGP <-> PIM Futures/Open Issues PIM State machine changes to interact with BGP. • No PIM hellos for option negotiation. Might be good to allow options to be carried in BGP. • No Join suppression or Prune override in PIM. Requires explicitly tracking downstream joiners in either PIM or BGP. • No support for Bidir DF Election. • No support for PIM Assert resolution.

  10. BGP <-> PIM Futures/Open Issues • PIM-SM shared tree pruning. Cannot preserve the full state nature of (*,G),(S,G,R) prunes in BGP. NLRI are not “associated” with each other => Re-flooding of the shared tree for pruned sources. • BSR mappings require “full state update” as well. • G/mask, RP1, RP2, RP3… For proper operation PIM needs all three RPs before it can make a decision based on the mapping. • Mappings carry holdtimes/priorities for RPs, where to put these, BGP attributes ?

  11. BGP Futures/Open Issues… • BGP will not restrict Binding state to multicast tree. • Not enough bits to encode SAFI length for IPv6!! • Need to define transition from LAN procedures to BGP.

  12. Comments / Questions ?

  13. Differences from other document • Differences from draft-raggarwa-l3vpn-2547bis-mcast-bgp-00.txt • Separate RTs for Multicast VPNs (required for correct functioning of extranets) • Tracking of Downstream PEs (required for SGR Joins/Prunes) • Does not require RT configuration on ASBRs • Aggregation done on ASBR • Differences in NLRI

More Related