Layer 2 Multicast Forwarding And Layer 3 Multicast Routing - Cisco Nexus 7000 Series Configuration Manual

VXLAN BGP EVPN and OTV Interoperation
• Configure the anycast gateway MAC address used in the VXLAN fabric as the HSRP MAC address in
• Layer 3 traffic between the legacy fabric and the IP WAN should be over OTV, MPLS L3VPN, or VRF
DC-4, the datacenter with the OTV+BDI switch as the one box solution
• Layer 3 routing within this datacenter is through an IGP implemented on the Layer 3 vPC switch pair
• When the Layer 3 DCI enabled border switch receives Layer 3 traffic from another site, it does a lookup
ARP requests
• All ARP requests are resolved through the VXLAN and/or OTV overlays.
• When ARP suppression is enabled on the VXLAN overlay NVE interface (for a specific Layer 2 virtual
• A Layer 3 gateway generated ARP request sent over OTV uses the primary gateway IP and virtual device
You should enable the ARP proxy function under the OTV overlay and ARP suppression function under
Note
the VXLAN overlay at the same time or you should disable both the functions.

Layer 2 Multicast Forwarding and Layer 3 Multicast Routing

Multicast traffic across the datacenters:
Layer 2 Multicast Forwarding
• When a server in the VXLAN BGP EVPN fabric sends multicast traffic to the attached ToR/leaf switch,
FHRP filtering is required to allow for the existence of the same default gateway in
Note
different locations and optimize outbound traffic flows (traffic from a server in DC-3
to another datacenter). See
more information.
the legacy fabric for efficient MAC moves.
Lite.
at the border. When a server in DC-4 sends traffic to a server in another VLAN/subnet, either located
within the site or in a remote site, the traffic first reaches the designated Layer-3 switch. If the destination
is within the fabric, it routes the packets (across VLANs, through the corresponding BDI) towards the
corresponding Layer 2 switch which forwards it to the destination. If the destination is in another site,
the Layer-3 border switch routes the traffic towards the remote site, through a Layer 3 DCI technology
like MPLS L3VPN or OTV, depending on how the host route was learnt (through MPLS VPN or OTV).
to find out where the destination server resides and routes the traffic through the IGP in the fabric, to
the corresponding Layer 2 switch. The switch forwards the packets to the intended destination server.
network[s]), then an ARP request is suppressed if the entry is present in the ARP cache. Else, the request
is flooded into the VXLAN fabric.
context (VDC) MAC addresses, while an ARP request sent over the VXLAN BGP EVPN fabric uses
the secondary BDI or anycast gateway IP and corresponding MAC addresses.
the leaf switch forwards the multicast traffic within the fabric, as explained in the Cisco Programmable
Fabric with VXLAN BGP EVPN Configuration Guide. If there are receivers in the Layer 2 CE pod
within DC-1, the leaf switch sends traffic towards the border switch, which VXLAN decapsulates the
Layer 2 Multicast Forwarding and Layer 3 Multicast Routing
Overlay Transport Virtualization Best Practices Guide
Cisco Nexus 7000 Series NX-OS VXLAN Configuration Guide
for
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