Multihoming in EVPN with InterAS Option B draftheitzbessevpnoptionb00

Multi-homing in EVPN with Inter-AS Option B draft-heitz-bess-evpn-optionb-00 IETF 96, July 2016 Berlin Jakob Heitz (Cisco) Ali Sajassi (Cisco) John Drake (Juniper) Jorge Rabadan (Nokia)

Intra-AS ASN=1 MAC route|RD=1. 1: 21|NH=1. 1 Egress PE 1 EAD per EVI route|RD=1. 1: 21|NH=1. 1 EAD per ES route |RD=1. 1: 41|NH=1. 1 CE Ingress PE 3 EAD per EVI route|RD=1. 1. 1. 2: 22|NH=1. 1. 1. 2 Egress PE 2 EAD per ES route |RD=1. 1. 1. 2: 42|NH=1. 1. 1. 2 draft-heitz-bess-evpn-optionb-00 2

Intra-AS Same Next-Hop. Mass withdraw ASN=1 ES fails MAC route|RD=1. 1: 21|NH=1. 1 Egress PE 1 EAD per EVI route|RD=1. 1: 21|NH=1. 1 EAD per ES route |RD=1. 1: 41|NH=1. 1 CE Ingress PE 3 Withdraw per ES EAD per EVI route|RD=1. 1. 1. 2: 22|NH=1. 1. 1. 2 Egress PE 2 EAD per ES route |RD=1. 1. 1. 2: 42|NH=1. 1. 1. 2 draft-heitz-bess-evpn-optionb-00 3

Intra-AS ASN=1 MAC route|RD=1. 1: 21|NH=1. 1 Egress PE 1 EAD per EVI route|RD=1. 1: 21|NH=1. 1 EAD per ES route |RD=1. 1: 41|NH=1. 1 CE Ingress PE 3 Same Next-Hop. Mass withdraw EAD per EVI route|RD=1. 1. 1. 2: 22|NH=1. 1. 1. 2 ES fails Egress PE 2 EAD per ES route |RD=1. 1. 1. 2: 42|NH=1. 1. 1. 2 Withdraw per ES draft-heitz-bess-evpn-optionb-00 4

Inter-AS Option B Same next-hop ASN=1 ASN=2 MAC route|RD=1. 1: 21|NH=2. 1. 1. 1 Egress PE 1 EAD per EVI route|RD=1. 1: 21|NH=2. 1. 1. 1 NH=1. 1 EAD per ES route |RD=1. 1: 41|NH=2. 1. 1. 1 CE ASBR 1 Ingress PE 3 ASBR 2 NH=2. 1. 1. 1 EAD per EVI route|RD=1. 1. 1. 2: 22|NH=2. 1. 1. 1 EAD per ES route |RD=1. 1. 1. 2: 42|NH=2. 1. 1. 1 Egress PE 2 NH=1. 1. 1. 2 draft-heitz-bess-evpn-optionb-00 5

EAD per ES route cannot be associated ASN=1 ES fails ASN=2 MAC route|RD=1. 1: 21|NH=2. 1. 1. 1 Egress PE 1 EAD per EVI route|RD=1. 1: 21|NH=2. 1. 1. 1 NH=1. 1 EAD per ES route |RD=1. 1: 41|NH=2. 1. 1. 1 CE ASBR 1 Ingress PE 3 ASBR 2 Withdraw per ES NH=2. 1. 1. 1 EAD per EVI route|RD=1. 1. 1. 2: 22|NH=2. 1. 1. 1 Egress PE 2 NH=1. 1. 1. 2 Rule: Mass Withdraw must not occur until all EAD per ES routes with a matching nexthop are withdrawn draft-heitz-bess-evpn-optionb-00 EAD per ES route |RD=1. 1. 1. 2: 42|NH=2. 1. 1. 1 Same next-hop. Which one failed? 6

Mass Withdraw per EVI ASN=1 Same RD. Mass Wdr the MAC ASN=2 Withdraw per EVI Egress PE 1 NH=1. 1 CE MAC route|RD=1. 1: 21|NH=2. 1. 1. 1 EAD per EVI route|RD=1. 1: 21|NH=2. 1. 1. 1 EAD per ES route |RD=1. 1: 41|NH=2. 1. 1. 1 ASBR 1 Ingress PE 3 ASBR 2 NH=2. 1. 1. 1 EAD per EVI route|RD=1. 1. 1. 2: 22|NH=2. 1. 1. 1 Egress PE 2 NH=1. 1. 1. 2 EAD per EVI is optional. If it never existed, then no mass withdrawal occurs. draft-heitz-bess-evpn-optionb-00 EAD per ES route |RD=1. 1. 1. 2: 42|NH=2. 1. 1. 1 7

Solution: PE of Origin ASN=1 Egress PE 1 NH=1. 1 CE ASN=2 ASBR 1 adds PEO. Copies NH+ASN into tunnel encap attribute ASBR 1 MAC route|RD=1. 1: 21|NH=2. 1. 1. 1|PEO=1. 1 EAD per EVI route|RD=1. 1: 21|NH=2. 1. 1. 1|PEO=1. 1 EAD per ES route |RD=1. 1: 41|NH=2. 1. 1. 1|PEO=1. 1 Ingress PE 3 ASBR 2 NH=2. 1. 1. 1 EAD per EVI route|RD=1. 1. 1. 2: 22|NH=2. 1. 1. 1|PEO=1. 1. 1. 2 Egress PE 2 EAD per ES route |RD=1. 1. 1. 2: 42|NH=2. 1. 1. 1|PEO=1. 1. 1. 2 NH=1. 1. 1. 2 draft-heitz-bess-evpn-optionb-00 8