VxLAN - underlay traffic to VxLAN

[kain.niak]

Hi guys,

I currently have some trouble with VXLAN.

Currently I want to test a simple topology with 1 Catalyst 9500 as spine switch and 2 Catalyst 9300 as leaf switch as below:

       

My current configuration is very simple:

• Underlay running OSPF
• Overlay running BGP
• VXLAN over BGP EVPN using multicast (PIM sparse-mode)
• No VRF/no border leaf

The l2vpn evpn is up, each vtep can learn MAC-address of the remote host. So I assume my VXLAN is successful.

But I'm unable to route normal traffic to VXLAN (host3 to host1/host2), ping is successful but other traffic has problem. It seems that from Spine switch, it see 2 different paths to the subnet 192.168.1.x via leaf1 and leaf2.

host3 >> spine >> leaf1 >> leaf2 >> host 2 >> leaf2 >> spine >> host3.

Does anyone have idea about this or any guide that I can follow to solve this problem?

Thank you!

[omz]

You dont connect end hosts to spines .. only leafs 

[kain.niak]

Yes. But this is just for lab purpose. This host3 stand for traditional network..

[MHM Cisco World]

Bro spine must not have any idea about the subnet,

The underlaying config to connect loopback "router id" of leaf to spine only.

The vxlan do the job of forward traffic between host.

Just remove subnet from ospf and let vxlan do forwarding 

[kain.niak]

Thanks. I'm just trying to tweak the usage of VXLAN a little bit. I'm having a case that need to extend a L2 network across 2 sites. We have 2 core (stacking virtual) and a L3 switch at each site.

The job is done easily with VXLAN. Next step is how to communicate with this VXLAN. Since this is just a small topo, I cannot afford a border node to let the traffic in VXLAN exit. I have some reference to other vendor and see they use something called naked routing or route leak to advertise routes.

Do you have any suggestion? I guess VXLAN or any L2 VPN method is not the solution for my case?

[BCKWDS]

Read up on Border Leaf or Border Spine for ISP connectivity then look into Multisite for connecting two remote locations.