Transcript 7_IETF97_draft-boutros-bess-vxlan-evpn-02

VXLAN DCI Using EVPN
draft-boutros-bess-vxlan-evpn-04.txt
Sami Boutros
Ali Sajassi
Samer Salam
Dennis Cai
Samir Thoria
Tapraj Singh
John Drake
Jeff Tantsura
IETF 97, Nov 2016
Seoul, South Korea
VXLAN DCI Using EVPN
• This is to provide intra-subnet connectivity at Layer
2 and control-plane separation among the
interconnected VXLAN or NVGRE networks over the
EVPN MPLS/IP network.
– The scope is limited to data plane learning in this
document.
Requirements
• Control Plane Separation among VXLAN/NVGRE
Networks.
• Layer 2 Extension over the MPLS/IP Network for
intra-subnet connectivity.
• Support for IRB for both inter-subnet routing and
intra-subnet bridging for a given VNI/VSID.
Solution overview
+-----------------+
|
|
+-----------+ +-----+ MPLS +------+ +----------+
+--------+ |
|---|PE1 |
|PE3 |--|
| +---------+
|VTEP1|--|
| +------+
+------+ |
|--|VTEP3|
+--------+ | VXLAN | +------+
+------+ | VXLAN| +--------+
+--------+ |
|---|PE2 |
|PE4 |--|
| +--------+
|VTEP2|--|
| +------+Backbone+------+ |
|--|VTEP4|
+--------+ +-----------+
+--------------+
+---------+ +--------+
|<------ IGP ------------->|<-----BGP-------------->|<------ IGP ---------->| CP
|<----- VXLAN --------->|<EVPN/PBB-EVPN>|<------ VXLAN ------->| DP
|<----MPLS----->|
Legend: CP = Control Plane View
DP = Data Plane View
EVPN Routes
• BGP MAC/B-MAC Advertisement Route for EVPN/PBB-EVPN
• Ethernet Auto-Discovery Route for EVPN
• Per VPN Route Targets
• Inclusive Multicast Route to distribute the VNI information over the MPLS
network.
• Discovery of the PEs participating in a given VNI.
• Stitching of the IP multicast trees, local to each VXLAN site, with the Label
Switched Multicast (LSM) trees of the MPLS network.
Handling Unicast traffic
• Host MAC addresses will be learnt in data plane from the VXLAN network.
• Host MAC addresses will be learnt over the MPLS/IP core:– In control plane for EVPN.
– In data plane [in case of PBB-EVPN].
• L2 Unicast traffic destined to the VXLAN network will be encapsulated with
the IP/UDP header+Customer bridge VNI.
• L2 Unicast traffic destined to the MPLS/IP network will be encapsulated
with the MPLS label.
• For redundancy an IP Anycast address MUST be used as the VTEP address
on all PEs multi-homed to a given VXLAN network.
– To prevent MAC Flip flopping.
– To enable ECMP from site to core and vice versa.
Handling Mcast traffic
• Each VXLAN network independently builds its P2MP or
MP2MP shared multicast trees for one or more VNIs.
– Use of PIM Bidir relaxing the RPF check for traffic coming from
multihomed DCI(s).
• In the MPLS/IP network, multiple options are available for the
delivery of multicast traffic:
– Ingress replication
– LSM Options.
• The stitching must ensure for MH VXLAN network:
– No Packet Duplication/Forwarding Loops
• Per VNI DF election for site to core and core to site at DCI(s).
– Multicast Stitching with Per-VNI Load Balancing
PIM SM operation
• With PIM SM, multicast traffic from the core-to-site coming from a
DCI could be dropped because of RPF.
• The proposal:
– DCI nodes join towards the RP for the multicast group for a particular
VXLAN.
– The multicast flow is identified as (anycast address, group) in the
register message, and the source address for the PIM-SM register
message should be a unique address on the DCI node not the anycast
address.
– The RP will send a join for the (anycast address, group) upon receiving
the register message, routed towards the closest DCI which could be
either the DF or the non-DF. This DCI will switch to send traffic natively.
– When VTEPs receive traffic from the RP, VTEPs will send (anycast
address, group) join, routed towards the closet DCI to each VTEP.
– This starts native forwarding on multiple PE nodes connected to the
VXLAN network, but each VTEP or transit router will only accept
multicast traffic from one of the multi-homed DCI nodes.
Different interconnect use cases
• Homogeneous Network DCI interconnect
– VNI Base Mode EVPN Service
– VNI Bundle Service
– VNI Translation
• Heterogeneous Network DCI
– VXLAN VLAN Interworking Over EVPN
Next steps
• Authors believe that document is ready for
WG adoption.
Thank you
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