New VXLAN configuration 9372

[waqas gondal]

Hi I am configuring a VXLAN for the first time on a production environment.

I have 2 Nexus 9372 switches at each site. At each site they are in a VPC pair. These switches will be the VTEPs

Multicast is not enabled on the underlying network but it will be on the VTEPs. I was told that this would still function as needed.

Jumbo frames and all necessary features have been enabled so I believe the prerequisites have been met. The routing protocol will be EIGRP.

My question is will configuration of the VXLAN cause any outage while traffic is passing through the VTEPs? And what would a config example look like in this scenario?

Thanks!

[Victor Acevedo]

Hey Waqas,

It depends what implementation of VxLAN you will be deploying. If you will be using EVPN VxLAN with Ingress Replication then we do not require the underlying network to support multicast. However, if you are using EVPN with VxLAN with multicast replication for BUM traffic then you will need multicast support on your core. 

The VxLAN configurations are pretty involved and should definitely be performed in a MW as you could see some issues if performed incorrectly or out of order. 

You can take a look at the following guide for VXLAN design and configurations:

VxLAN Design Guide for Nexus 9300 platform

[waqas gondal]

Thanks for the help Victor.

I read through the document and I'm not sure what EVPN or ingress replication is.

Our design will be like this with 2 VTEPS in each Pod.

Also since I am using vPC pairs at each site would this be a good config example to follow for Pod 1? (swapping ospf with eigrp)

I noticed that they use the same IP address as a secondary on the loopback interface, is that correct?

[Victor Acevedo]

Hey Waqas,

Yes, for vPC VTEPs we must share the same IP address on the loopbacks as a secondary address. 

Ethernet VPN (EVPN) and essentially we will use BGP and this EVPN address-family to advertise VXLAN information such as MACs and IP's learnt over the fabric

BUM (Broadcast, Unknown Unicast, Multicast) - can use IR or multicast replication 

Ingress Replication (IR) - We will use unicast to replicate BUM traffic to all of our VTEP peers

Multicast Replication - We will set a multicast group that we can use and rely on multicast in the core to replicate this traffic to our VTEPs

Thx,

Vic

[waqas gondal]

Thanks Victor,

In that case we aren't using EVPN so Multicast will need to be enabled on our underlying network.

Thanks for the help.

-Waqas

[Victor Acevedo]

Hey Waqas,

That is correct. 

Glad I could help. 

Thanks,

Vic