EVPN Interworking with IPVPN draft-rabadan-sajassi-bess-evpn-ipvpn-interworking-01 Jorge Rabadan (Nokia) Ali Sajassi (Cisco) Eric Rosen (Juniper) John Drake (Juniper) Wen Lin (Juniper) Jim Uttaro (AT&T) Adam Simpson (Nokia) IETF102, Jul 2018 Montreal

Refreshing the objective VPN-IPv4 A/32 RT-5 A/32 GW1 RR PE1 IP-VRF 1 Tenant Subnets IP-VRF 1 A tenant network may span multiple domains where different Inter- Subnet-Forwarding SAFIs (ISF SAFIs) may provide inter-subnet connectivity. EVPN domain-1 IPVPN domain IP-VRF 1 GW2 This document addresses the interworking aspects between ISF-SAFIs when one of them is EVPN: BGP route selection Loop Prevention Path Attribute Propagation Route Aggregation (new in rev 01)

How can a DOMAIN be defined? EVPN GW PE GW PE BGP LU ASBR ASBR PE IP-VRF 1 IP-VRF 1 PE PE PE IP-VRF 1 IP-VRF 1 EVPN IPVPN EVPN IP-VRF 1 IP-VRF 1 IP-VRF 1 IP-VRF 1 GW PE GW PE ASBR ASBR DOMAIN 1 DOMAIN 2 DOMAIN 3 DOMAIN 1 DOMAIN LIMITS Two PEs are in the same Domain if there are no (tenant) IP lookups in intermediate routers. A GW is always configured with multiple Domain_IDs DOMAIN IDs A GW is always configured with multiple Domain_IDs

Building blocks: DOMAIN types and PE types COMPOSITE DOMAIN Uses a multiple ISF SAFIs 1 2 REGULAR DOMAIN Uses a single ISF SAFI EVPN PE IW PE EVPN IP-VRF 1 EVPN PE IW PE IPVPN PE RR IP-VRF 1 EVPN IPVPN IPVPN EVPN IP-VRF 1 IP-VRF 1 IP-VRF 1 IPVPN IP-VRF 1 IPVPN PE REGULAR DOMAIN 1 REGULAR DOMAIN 2 COMPOSITE PE Interworking PE, attached to a COMPOSITE DOMAIN, uses multiple ISF SAFIs to the RRs REGULAR PE Attached to a DOMAIN, uses only one ISF SAFI GW PE Interworking PE, attached to two DOMAINs (REGULAR or COMPOSITE), propagates the same or different ISF SAFI routes B A C

Domain Path Attribute (D-PATH) A new attribute for loop protection and ISF SAFI visibility EVPN PE1 GW PE1 GW PE2 EVPN PE2 EVPN IPVPN IPVPN Length field followed by a sequence of Domain segments, where each Domain segment is represented by <DOMAIN-ID:ISF_SAFI_TYPE> D-PATH used for Loop Prevention: any PE that imports a Prefix route MUST drop the route if its D- PATH contains a <DOMAIN- ID:ISF_SAFI_TYPE> segment, where DOMAIN-ID matches a local DOMAIN-ID IP-VRF 1 IP-VRF 1 IP-VRF 1 IP-VRF 1 REGULAR DOMAIN 65000:3 REGULAR DOMAIN 65000:2 REGULAR DOMAIN 65000:1 EVPN RT-5 10.0.0.0/24 VPN-IPv4 10.0.0.0/24 [6500:1:EVPN] EVPN RT-5 10.0.0.0/24 [6500:2:IPVPN] [6500:1:EVPN]

BGP Path Propagation Across ISF-SAFIs Two modes of operation No Propagation mode (default) Uniform Propagation mode Uniform Propagation: AS_PATH D-PATH IBGP-only Path Attributes: LOCAL_PREF, ORIGINATOR_ID, CLUSTER_ID MED AIGP Communities, (non-EVPN) Extended Communities and Large Communities

Route Selection Between EVPN and other ISF-SAFIs VPN-IPv4 10.0.0.1/32 LP 200 Between EVPN and other ISF-SAFIs EVPN RT-5 10.0.0.1/32 [6500:2:IPVPN] [6500:1:EVPN] Removes from consideration the routes following the rules and the order defined in [RFC4271], with the following exceptions and in the following order: After removing from consideration lowest Local Preference, any routes that do not have the shortest D-PATH are also removed from consideration. Routes with no D-PATH are considered to have a zero- length D-PATH. Then regular [RFC4271] selection criteria is followed. If at least one route still under consideration is an RT-2 route, remove from consideration any RT-5 routes. Steps 1-3 could possibly leave Equal Cost Multi-Path (ECMP) between IP and EVPN paths. By default, the EVPN path is considered If ECMP across ISF SAFIs is enabled by policy, and an "IP path" and an "EVPN path" remain at the end of step 3, both path types will be used. GW 1 IP-VRF 1 EVPN RT-2 10.0.0.1/32 [6500:2:IPVPN]

EVPN and IPVPN Interworking Changes in rev 01 Terminology section clarified and general cleaning (credits to John) Some procedures are clarified Route Aggregation section added

Aggregation of Routes to minimize the impact of host routes in DCs And Path Attribute Propagation EVPN RT-5 10.0.0.1/32 Combination of the characteristics of multiple ISF routes of the same ISF SAFI in such way that a single aggregate ISF route of a different ISF SAFI can be propagated. Done ONLY by a gateway PE. If Uniform Propagation mode is used: AS_PATH aggregated based on [RFC4271]. ISF routes that have different attributes of the following type codes MUST NOT be aggregated: D- PATH, LOCAL_PREF, ORIGINATOR_ID, CLUSTER_ID, MED or AIGP. Community, Extended Community and Large Community attributes of the aggregate ISF route MUST contain all the Communities/Extended Communities/Large Communities from all of the aggregated ISF routes. EVPN RT-5 10.0.0.2/32 VPN-IPv4 10.0.0.0/24 [6500:3:EVPN] EVPN RT-5 10.0.0.3/32 EVPN PE1 GW PE1 EVPN IPVPN IP-VRF 1 IP-VRF 1 REGULAR DOMAIN 65000:3 REGULAR DOMAIN 65000:2

Next steps The Authors would like to request Working Group Adoption

Thank you