Aliasing

Following the example in Figure 1, if the service configuration on PE3 has ECMP > 1, PE3 adds PE1 and PE2 to the list of next-hops for ESI-1. As soon as PE3 receives a MAC for ESI-1, it starts load-balancing between PE1 and PE2 the flows to the remote ESI CE. The following command shows the FDB in PE3.

Note: MAC 00:ca:ca:ba:ce:03 is associated with the Ethernet-Segment eES:01:00:00:00:00:71:00:00:00:01 (esi configured on PE1 and PE2 for ESI-1).
*A:PE3# show service id 1 fdb detail 
===============================================================================
Forwarding Database, Service 1
===============================================================================
ServId    MAC               Source-Identifier        Type     Last Change
                                                     Age      
-------------------------------------------------------------------------------
1         00:ca:ca:ba:ce:03 eES:                     Evpn     06/11/15 00:14:47
                            01:00:00:00:00:71:00:00:00:01
1         00:ca:fe:ca:fe:69 eMpls:                   EvpnS    06/11/15 00:09:18
                            192.0.2.69:262141
1         00:ca:fe:ca:fe:70 eMpls:                   EvpnS    06/11/15 00:09:18
                            192.0.2.70:262140
1         00:ca:fe:ca:fe:72 eMpls:                   EvpnS    06/11/15 00:09:39
                            192.0.2.72:262141
-------------------------------------------------------------------------------
No. of MAC Entries: 4
-------------------------------------------------------------------------------
Legend:  L=Learned O=Oam P=Protected-MAC C=Conditional S=Static
===============================================================================

The following command shows all the EVPN-MPLS destination bindings on PE3, including the ES destination bindings.

The Ethernet-Segment eES:01:00:00:00:00:71:00:00:00:01 is resolved to PE1 and PE2 addresses:

*A:PE3# show service id 1 evpn-mpls 
===============================================================================
BGP EVPN-MPLS Dest
===============================================================================
TEP Address     Egr Label     Num. MACs   Mcast           Last Change
                 Transport                                
-------------------------------------------------------------------------------
192.0.2.69      262140        0           Yes             06/10/2015 14:33:30
                ldp                                        
192.0.2.69      262141        1           No              06/10/2015 14:33:30
                ldp                                        
192.0.2.70      262139        0           Yes             06/10/2015 14:33:30
                ldp                                        
192.0.2.70      262140        1           No              06/10/2015 14:33:30
                ldp                                        
192.0.2.72      262140        0           Yes             06/10/2015 14:33:30
                ldp                                        
192.0.2.72      262141        1           No              06/10/2015 14:33:30
                ldp                                        
192.0.2.73      262139        0           Yes             06/10/2015 14:33:30
                ldp                                        
192.0.2.254     262142        0           Yes             06/10/2015 14:33:30
                bgp                                        
-------------------------------------------------------------------------------
Number of entries : 8
-------------------------------------------------------------------------------
===============================================================================
===============================================================================
BGP EVPN-MPLS Ethernet Segment Dest
===============================================================================
Eth SegId                     TEP Address     Egr Label   Last Change
                                               Transport  
-------------------------------------------------------------------------------
01:00:00:00:00:71:00:00:00:01 192.0.2.69      262141      06/10/2015 14:33:30
                                              ldp          
01:00:00:00:00:71:00:00:00:01 192.0.2.72      262141      06/10/2015 14:33:30
                                              ldp          
01:74:13:00:74:13:00:00:74:13 192.0.2.73      262140      06/10/2015 14:33:30
                                              ldp          
-------------------------------------------------------------------------------
Number of entries : 3
-------------------------------------------------------------------------------
===============================================================================

PE3 performs aliasing for all the MACs associated with that ESI. This is possible because PE1 is configured with ECMP parameter >1:

*A:PE3>config>service>vpls# info 
----------------------------------------------
            bgp
            exit
            bgp-evpn
                evi 1
                mpls bgp 1
                    ecmp 4
                    auto-bind-tunnel
                        resolution any
                    exit
                    no shutdown
                exit
            exit
            proxy-arp
                shutdown
            exit
            stp
                shutdown
            exit
            sap 1/1/1:2 create
            exit
            no shutdown