API Guide

The interface IP address must be unique on each VTEP, including VTEPs in VLT pairs. You can configure an IPv6 address on the
virtual-network interface. Different virtual-network interfaces you configure on the same VTEP must have virtual-network IP
addresses in different subnets. If you do not assign the virtual-network interface to a tenant VRF, it is assigned to the default VRF.
interface virtual-network vn-id
ip vrf forwarding tenant-vrf-name
ip address ip-address/mask
no shutdown
exit
4. Configure an anycast gateway IPv4 or IPv6 address for each virtual network in INTERFACE-VIRTUAL-NETWORK mode. This anycast
IP address must be in the same subnet as the IP address of the virtual-network interface in Step 3.
Configure the same IPv4 or IPv6 address as the anycast IP address on all VTEPs in a virtual network. All hosts use the anycast
gateway IP address as the default gateway IP address in the subnet that connects to the virtual-network interface configured in Step
3. Configure the anycast gateway IP address on all downstream VMs. Using the same anycast gateway IP address allows host VMs to
move from one VTEP to another VTEP in a VXLAN. Dell EMC recommends using an anycast gateway in both VLT and non-VLT
VXLAN configurations.
interface virtual-network vn-id
ip virtual-router address ip-address
Configuration notes for virtual-network routing:
• VXLAN overlay routing includes routing tenant traffic on the ingress VTEP and bridging the traffic on the egress VTEP. The ingress
VTEP learns ARP entries and associates all destination IP addresses of tenant VMs with the corresponding VM MAC addresses in the
overlay. On the ingress VTEP, configure a virtual network for each destination IP subnet even if there are no locally attached hosts for
an IP subnet.
• Routing protocols, such as Open Shortest Path First (OSPF) and BGP, are not supported on the virtual-network interface in the
overlay network. However, static routes that point to a virtual-network interface or to a next-hop IP address that belongs to a virtual-
network subnet are supported.
• When you add a static route in the overlay, any next-hop IP address that belongs to a virtual-network subnet must be the only next-
hop for that route and cannot be one of multiple ECMP next-hops. For example, if you enter the following configuration commands
one after the other, where 10.250.0.0/16 is a virtual-network subnet, only the first next-hop is active on the switch.
OS10(config)# ip route 0.0.0.0/0 10.250.0.101
OS10(config)# ip route 0.0.0.0/0 10.250.0.102
If the next-hop is a pair of dual-homed VTEPs in a VLT domain, a workaround is to configure the same anycast gateway IP address on
both VTEPs and use this address as the next-hop IP address.
• VLT peer routing is not supported in a virtual network. A packet destined to the virtual-network peer MAC address L2 switches
instead of IP routes. To achieve active-active peer routing in a virtual network, configure the same virtual anycast gateway IP and
MAC addresses on both VTEP VLT peers and use the anycast IP as the default gateway on the VMs.
• Virtual Router Redundancy Protocol (VRRP) is not supported on a virtual-network interface. Configure the virtual anycast gateway IP
address to share a single gateway IP address on both VTEP VLT peers and use the anycast IP as default gateway on the VMs.
• Internet Group Management Protocol (IGMP) and Protocol-Independent Multicast (PIM) are not supported on a virtual-network
interface.
• IP routing of incoming VXLAN encapsulated traffic in the overlay after VXLAN termination is not supported.
The following tables show how to use anycast gateway IP and MAC addresses in a data center with three virtual networks and multiple
VTEPs:
• Globally configure an anycast MAC address for all VTEPs in all virtual networks. For example, if you use three VTEP switches in three
virtual networks:
Table 1. MAC address for all VTEPs
Virtual network VTEP Anycast gateway MAC address
VNID 11
VTEP 1
VTEP 2
VTEP 3
00.11.22.33.44.55
00.11.22.33.44.55
00.11.22.33.44.55
VNID 12
VTEP 1
VTEP 2
00.11.22.33.44.55
00.11.22.33.44.55
12 VXLAN