Multi-homed network in EVPN draft-hao-evpn-mhn-00 July 20131MHN in EVPN Weiguo Hao(Huawei) Yizhou Li(Huawei) Pei Xu(Huawei) July, 2013 Berlin Germany

EVPN Network Multi-homed network (MHN) in EVPN scenarios July 20132MHN in EVPN PE1 PE2 B1 B2 B3 Bridged 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. ES1 ES2 ES3

DF Mechanism July 20133MHN in EVPN  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. EVPN Network PE1 PE2 B1(STP Root) B2 B3 BLOCKED MSTP Network ES1 ES2 ES3 EVPN For DF Non- DF ES1,ES2 and ES3 access to EVPN network through PE1

Active/Active MAC-based load balancing mechanism July 20134MHN in EVPN EVPN Network PE1 PE2 B1 B2 B3 BLOCKED MSTP Network ES1 ES2 ES3 ES1 and ES2 access to EVPN network through PE1 BLOCKED ES3 accesses to EVPN network through PE2  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.

Emulated MSTP root bridge solution July 20135MHN in EVPN EVPN Network PE1 PE2 B1(STP Root) B2 B3 BLOCKED MSTP Network ES1 ES2 ES3 BLOCKED PE1 and PE2 emulate MSTP root bridge  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. PE3

Bridge control plane protocol tunneling solution EVPN Network PE1(ST P Root) PE2 B1 B2 B3 BLOCKED MSTP Network ES1 ES2 ES3 BLOCKED PE3 BPDU tunnel EVPN Network PE1 PE2 B1 B2 B3 BLOCKED G.8032 Network ES1 ES2 ES3 BLOCKED PE3 G.8032 message tunnel RPL owner node MHN in EVPNJuly 2013 RPL owner node The cost should be set to 0 to avoid blocking

Bridge control plane protocol tunneling solution July 2013MHN in EVPN7 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.

EVPN protocol extension July 20138MHN in EVPN  "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 | Type=0x06 | Sub-Type=0x01 |DF|R|M| Reserved=0 | | Reserved = 0| ESI Label | ESI Label Extended Community

Next Steps July 20139MHN in EVPN Does WG think this can be put into EVPN base protocol? Any other comments and suggestions?