mix evpn and multicast/drive drive dataplane problem.

[fly]

Hi,

   I need one pure multicast drived layer 2 vxlan vtep(vtep don't run bgp) can communicate with another set of vtep running bgp as control protocol (also config same layer 2 vni)

Can  I config different set of vxlan vtep L2 gateway like this:

1、many sets of  vtep config bgp under interface nve，using bgp as control protcol

vni 10022 is layer 2 vni

12022 is layer 3 vni

nexus 93180YC-EX-1

interface nve1
  no shutdown
  host-reachability protocol bgp
  source-interface loopback1
  member vni 10022
    mcast-group 239.0.20.2
  member vni 12022 associate-vrf

2、one set of vtep config like this，didn't config bgp as control protocol 

just need layer 2 vni 10022 can communicate with other sets of vtep 

nexus 93180YC-EX-11

interface nve1
  no shutdown
  source-interface loopback1
 member vni 10022
    mcast-group 239.0.20.2

But I tested it , can't get communication between bgp tep and pure multicast dataplane drived vtep.

how I can I do this, because one set of nexus 93180YC-EX can't run bgp due to customer's reason

  thank you

Andy

[Hanfeng Cai]

To be honest, it's impossible......

EVPN need BGP to let each vtep have readability.

[fly]

 I think whatever BGP as CP or multicast drive learned mac-ip , they just form same l2route table for forwarding .

why I can't get communication under this scene

if mac-a ip-a PC send arp to query mac-b ip-b, if arp reach vtep-a(pure multicast drive) , It will be send as multicast packet(I can see this packet by using monitor), and It will reach destination vtep-b,(vte-b configure bgp and multicast.), vtep-b store mac-a ip-b to local table and send arp to mac-b ip-b, ip-b pc return to vtep-b ,     vtep-b check local table and send return packet to vtep-a(encapsulate in vxlan), it will reach mac-a ip-a pc-a

you can see if one site no bgp ,we can use multicast to "find“ vtep.

I am little confusing

thank you