1. Optimized Ingress Replication solution for EVPN
draft-rabadan-l2vpn-evpn-optimized-ir-00
Jorge Rabadan
Senthil Sathappan
Wim Henderickx
Mukul Katiyar
Ravi Shekhar
Nischal Sheth
Wen Lin
IETF 90, July 2014
Toronto, Canada

2. draft-rabadan-l2vpn-evpn-optimized-ir-00
When EVPN is used as the control plane for NVO networks, what options do we have to transport BUM?
Ingress Replication
PIM-based Trees
No dependencies on the underlay network core
Enough if the tenant does not use multicast applications (EVPN optimizes B/U)
Inefficient for highly demanding multicast applications
Dependencies on the underlay network core
Creates states in the core
Efficient    
Alignment includes: terminology, DF SHOULD send the ESI label to non-DF too, set of AD routes per EVI with 4k RTs (as opposed to 1)  
IR is the preferred solution when independency between overlay and underlay core is required
draft-rabadan-l2vpn-evpn-optimized-ir-00
IETF90 – July 2014

3. VXLAN/NVGRE/MPLSoGRE
Problem statement: IR is inefficient and may be too expensive for low-performance NVEs
VXLAN/NVGRE/MPLSoGRE
IP Fabric
TOR
EVI-1
Hypervisor
NVE-1
VM1
Mcast Source
Tenant Systems
NVE-2
NVE-3
PE1
PE2
TS1
TS2
Alignment includes: terminology, DF SHOULD send the ESI label to non-DF too, set of AD routes per EVI with 4k RTs (as opposed to 1) 2
Applications can be seriously affected in low-performance-replication NVEs 1
NVEs might not be interested in all B/U/M traffic
draft-rabadan-l2vpn-evpn-optimized-ir-00
IETF90 – July 2014

4. Solution: Optimized-IR for EVPN
ASSISTED-REPLICATION
(AR) 2 1
PRUNED-FLOOD-LISTS
(PFL)
Optimizes BM IR for low-performance-replication NVEs
Prunes non-interested NVEs from BM/U flooding list
Alignment includes: terminology, DF SHOULD send the ESI label to non-DF too, set of AD routes per EVI with 4k RTs (as opposed to 1)
Backwards-compatible with existing NVEs
Backwards-compatible with existing NVEs
draft-rabadan-l2vpn-evpn-optimized-ir-00
IETF90 – July 2014

5. EVPN BGP attributes for optimized-IR
New proposal
AR type field
00 = RNVE (non-AR support)
01 = AR-Replicator
10 = AR-Leaf
PFL flags
BM (Broadcast and Multicast)
U (Unknown)
1 = “prune me”
0 = regular behavior
Inclusive Multicast Ethernet Tag Route 1 2 3 4 5 6 7
Route Distinguisher(8 byte)
Ethernet Tag ID (4 bytes)
IP Address Length (1 byte)
Originating Router’s IP addr
(4 or 16 bytes)
Rsvd
Type BM U L
Flags (1 byte)
Tunnel Type (1 byte)= IR or AR
MPLS label (3 bytes)
Tunnel Identifier (variable)
PMSI Tunnel Attribute
Alignment includes: terminology, DF SHOULD send the ESI label to non-DF too, set of AD routes per EVI with 4k RTs (as opposed to 1)
AR ROLE
FUNCTION
Inc. Mcast Route information
AR-REPLICATOR
Assists AR-leafs
IR incl. mcast route (IR IP)
AR incl. mcast route (AR IP, tunnel=AR, T=1)
AR-LEAF
Sends BM only to AR-Rep
IR incl. mcast route (IR IP, T=2)
RNVE
Non-AR support
draft-rabadan-l2vpn-evpn-optimized-ir-00
IETF90 – July 2014

6. Broadcast/Multicast forwarding
ASSISTED-REPLICATION
(AR)
Broadcast/Multicast forwarding B
AR-R
AR-R
AR-R
AR-R
AR-LEAF
RNVE
AR-LEAF
AR-LEAF
RNVE
AR-LEAF A
BM received on AR-R AC
Normal IR
BM received on AR-LEAF AC
AR-R selected by AR-LEAF
AR IP used as IP DA
AR-R forwards based on IP lookup
Unknown unicast follows IR to avoid packet re-ordering
Alignment includes: terminology, DF SHOULD send the ESI label to non-DF too, set of AD routes per EVI with 4k RTs (as opposed to 1)
AR-R
AR-R
AR-LEAF
RNVE
AR-LEAF
BM received on RNVE AC
Normal IR C
BM on AC
BM on overlay tunnel
draft-rabadan-l2vpn-evpn-optimized-ir-00
IETF90 – July 2014

7. Use of PFL in optimized-IR
PRUNED-FLOOD-LISTS
(PFL)
Use of PFL in optimized-IR B
AR-R
AR-R
AR-R
AR-R
AR-LEAF
RNVE
AR-LEAF
AR-LEAF
RNVE
AR-LEAF A
PFL can be used independently of AR
PFL flags are used in IR incl. Mcast routes
In this example NVEs in hypervisors are not interested in receiving unknown unicast
Alignment includes: terminology, DF SHOULD send the ESI label to non-DF too, set of AD routes per EVI with 4k RTs (as opposed to 1)
AR-R
AR-R
AR-LEAF
RNVE
AR-LEAF C
Unknown on AC
Unknown on overlay tunnel
draft-rabadan-l2vpn-evpn-optimized-ir-00
IETF90 – July 2014

8. Conclusions and next steps
Ingress replication is the preferred way of sending BUM in an EVPN-overlay network.
Optimized-IR proposes a solution to improve the performance in NVEs with poor replication capabilities (AR) and avoids the replication of BUM to uninterested NVEs (PFL).
The authors request feedback from the WG
draft-rabadan-l2vpn-evpn-optimized-ir-00
IETF90 – July 2014