[j-nsp] BGP EVPN, VXLAN and ECMP

[Vincent Bernat]

Hey!

I am trying to setup a Juniper QFX5100 as a VTEP with a very classic
setup. Everything works as expected, but the setup is only using one
possible path from the underlay network.

I have the route to the other VTEP like this:

# run show route 10.16.39.3

inet.0: 240 destinations, 1808 routes (240 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

10.16.39.3/32      *[BGP/140] 00:38:24, localpref 500, from 10.64.0.5
                      AS path: I, validation-state: unverified
                      to 10.64.0.23 via xe-0/0/46.181
                    > to 10.64.128.23 via xe-0/0/47.183
                    [BGP/140] 00:38:24, localpref 500, from 10.64.128.6
                      AS path: I, validation-state: unverified
                    > to 10.64.128.23 via xe-0/0/47.183
                    [BGP/140] 00:38:24, localpref 500, from 10.64.0.3
                      AS path: I, validation-state: unverified
                    > to 10.64.0.23 via xe-0/0/46.181

:vxlan.inet.0: 17 destinations, 21 routes (17 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

10.16.39.3/32      *[Static/1] 00:31:10, metric2 0
                    > to 10.64.128.23 via xe-0/0/47.183

So, from an IP point of view, I have two available routes to the other
VTEP. In the :vxlan.inet.0 table, only one route is kept. I suppose the
problem is at this point.

Looking at the forwarding table, I have only one indirect next-hop too:

# show route forwarding-table family ethernet-switching bridge-domain vlan-client1-543 extensive
   Routing table: default-switch.bridge [Index 4] 
   Bridging domain: vlan-client1-543.bridge [Index 3] 
   VPLS:
   Enabled protocols: Bridging, ACKed by all peers, 
       
[...]       
   Destination:  0a:e3:40:00:00:d9/48
     Learn VLAN: 0                        Route type: user                  
     Route reference: 0                   Route interface-index: 575 
     Multicast RPF nh index: 0         
     P2mpidx: 0              
     IFL generation: 142                  Epoch: 0   
     Sequence Number: 0                   Learn Mask: 0x4000000000000000000000000000000000000000
     L2 Flags: control_dyn
     Flags: sent to PFE
     Next-hop type: composite             Index: 2045     Reference: 6    
     Next-hop type: indirect              Index: 131317   Reference: 3    
     Nexthop: 10.64.128.23
     Next-hop type: unicast               Index: 1928     Reference: 4    
     Next-hop interface: xe-0/0/47.183

So, how to ensure the two possible next-hops are copied to the
":vxlan.inet.0" table?
-- 
Make input easy to prepare and output self-explanatory.
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