Multi-homed network in EVPN draft-hao-evpn-mhn-00

1. Multi-homed network in EVPN draft-hao-evpn-mhn-00 WeiguoHao(Huawei) Yizhou Li(Huawei) Pei Xu(Huawei) haoweiguo@huawei.com liyizhou@huawei.com xupei@huawei.com July, 2013 Berlin Germany MHN in EVPN

2. Multi-homed network (MHN) in EVPN scenarios EVPN Network There are two categories of mechanisms to avoid the layer 2 traffic loop. 1, PEs doesn’t participate in the control protocol of the bridged network , that is designated forwarder (DF) election mechanism. 2, PEs participate in the control protocol of the bridged network, active/active MAC-based load balancing can be achieved through the solution. PE1 PE2 B1 B2 ES3 ES1 B3 ES2 Bridged Network MHN in EVPN

3. DF Mechanism EVPN Network EVPN For DF PE1 PE2 ES1,ES2 and ES3 access to EVPN network through PE1 Non-DF • VLAN-based load balancing among PEs can be achieved. • Only one of the links between the • switched bridged network and the PEs is active for a given VLAN. • All end systems of one VLAN can access the EVPN network through only one PE. B1(STP Root) B2 ES3 ES1 BLOCKED B3 ES2 MSTP Network MHN in EVPN

4. Active/Active MAC-based load balancing mechanism EVPN Network • The mechanism requires PEs participate in the control plane protocol of the bridged network. • per-vlan MAC-based load balancing can be achieved through the mechanism , so it can achieve better load balancing than DF election. • Two solutions: • 1, emulated MSTP root bridge solution. • 2, bridge control plane protocol tunneling solution. PE1 PE2 ES1 and ES2 access to EVPN network through PE1 ES3 accesses to EVPN network through PE2 B1 B2 BLOCKED ES3 ES1 BLOCKED B3 ES2 MSTP Network MHN in EVPN

5. Emulated MSTP root bridge solution PE3 EVPN Network PE1 and PE2 emulate MSTP root bridge PE1 PE2 • PE1 & PE2 use the same bridge ID to emit spanning tree BPDUs as the highest priority • root Bx. • When PE2 receives TC BPDU from the bridge network , PE2 tunnel the TC BPDU to PE1. • This solution is only applicable for STP/MSTP network. B1(STP Root) BLOCKED B2 ES3 ES1 BLOCKED B3 ES2 MSTP Network MHN in EVPN

6. Bridge control plane protocol tunneling solution PE3 PE3 EVPN Network The cost should be set to 0 to avoid blocking EVPN Network BPDU tunnel G.8032 message tunnel PE1(STP Root) PE2 PE1 PE2 RPL owner node BLOCKED BLOCKED B1 B2 B1 B2 ES3 ES3 ES1 BLOCKED ES1 BLOCKED B3 B3 RPL owner node ES2 ES2 MSTP Network G.8032 Network MHN in EVPN

7. Bridge control plane protocol tunneling solution The solution can be used for both MSTP and G.8032 domain. Scenario 1: Local bridged network is MSTP PE1 and PE2 act as normal MSTP bridge nodes. BPDU message can be sent through tunnel over EVPN network between PE1 and PE2. Scenario 2: Local bridged network is G.8032 PE1 and PE2 act as normal G.8032 ring nodes. They support standard FDB MAC learning, forwarding, flush behavior and port blocking/unblocking mechanisms. G.8032 message can be sent through tunnel over EVPN network between PE1 and PE2. MHN in EVPN

8. EVPN protocol extension 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type=0x06 | Sub-Type=0x01 |DF|R|M| Reserved=0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved = 0| ESI Label | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ESI Label Extended Community • "M" bit is introduced to indicate multi-homing mode of MAC-based all active without DF Election. • DF selection procedures should be skipped if "M" bit is set to be 1. • When remote PE receives Ethernet A-D route withdraw message, it simply invalidates the MAC entries for the segment that corresponding to the Ethernet A-D route. MHN in EVPN

9. Next Steps • Does WG think this can be put into EVPN base protocol? • Any other comments and suggestions? MHN in EVPN