Connectivity Guide

*> Route distinguisher: 110.111.170.107:64536
[3]:[0]:[32]:[110.111.170.107]/152 110.111.170.107 0 100 0 100 101 ?
Display the EVPN routes for host MAC addresses
OS10# show evpn mac
Type -(lcl): Local (rmt): remote
EVI Mac-Address Type Seq-No Interface/Next-Hop
50 00:00:00:aa:aa:aa rmt 0 55.1.1.3
50 00:00:00:cc:cc:cc lcl 0 ethernet1/1/8:1
OS10# show evpn mac evi 50
Type -(lcl): Local (rmt): remote
EVI Mac-Address Type Seq-No Interface/Next-Hop
50 00:00:00:aa:aa:aa rmt 0 55.1.1.3
50 00:00:00:cc:cc:cc lcl 0 ethernet1/1/8:1
VXLAN BGP EVPN routing
Configure BGP EVPN for VXLAN describes how EVPN facilitates traffic switching within the same L2 tenant segment virtual
network on a VTEP for virtual networks that associate with EVIs. This section describes how EVPN implements overlay routing
between L2 segments associated with EVIs belonging to the same tenant on a VTEP. IETF draft draft-ietf-bess-evpn-inter-
subnet-forwarding-05 describes EVPN inter-subnet forwarding, Integrated Routing and Bridging (IRB), and how to use EVPN
with IP routing between L2 tenant domains.
As described in Configure VXLAN — Enable overlay routing between virtual networks, you set up overlay routing by assigning
a VRF to each tenant, creating a virtual-network interface, and assigning an IP subnet in the VRF to each virtual-network
interface. The VTEP acts as the L3 gateway that routes traffic from one tenant subnet to another in the overlay before
encapsulating it in the VXLAN header and transporting it over the underlay fabric. On virtual networks that associate with EVIs,
EVPN IRB is enabled only after you create a virtual-network interface.
When you enable IRB for a virtual network/EVI, EVPN operation on each VTEP also advertises the local tenant IP-MAC bindings
learned on the EVPN-enabled virtual networks to all other VTEPs. The local tenant IP-MAC bindings are learned from ARP or
ICMPv6 protocol operation. They advertise as EVPN Type-2 BGP route updates to other VTEPs, each of whom then imports
and installs them as ARP/IPv6 neighbor entries in the dataplane.
To enable efficient traffic forwarding on a VTEP, OS10 supports distributed gateway routing. A distributed gateway allows
multiple VTEPs to act as the gateway router for a tenant subnet. The VTEP that is located nearest to a host acts as its gateway
router.
To enable L3 gateway/IRB functionality for BGP EVPN, configure a VXLAN overlay network and enable routing on a switch:
1. Create a non-default VRF instance for overlay routing. For multi-tenancy, create a VRF instance for each tenant.
2. Cconfigure globally the anycast gateway MAC address used by all VTEPs.
3. Configure a virtual-network interface for each virtual network, (optional) assign it to the tenant VRF, and configure an IP
address. Then enable the interface.
4. Configure an anycast gateway IP address for each virtual network. OS10 supports distributed gateway routing.
For more information, see Configure VXLAN — Enable overlay routing between virtual networks.
EVPN supports different types of IRB routing for tenants, VMs and servers, that connect to each VTEP in a tenant network.
● Asymmetric routing: IP routing is performed on ingress VTEPs. L2 bridging is performed on egress VTEPs. You must
configure an ingress VTEP with a virtual network even for destination IP subnets that have no locally attached hosts. EVPN
asymmetric IRB installs ARP entries to associate each tenant VM IP address with its corresponding VM MAC address in the
overlay.
● Symmetric routing: IP routing is performed on both ingress and egress VTEPs. You do not have to configure an ingress
VTEP with a virtual network for destination IP subnets that have no locally attached hosts. EVPN symmetric IRB installs ARP
entries to associate each tenant VM destination IP address with the MAC address of the VTEP where the VM is located,
reducing the number of required hardware next-hop routing resources.
NOTE: In release 10.4.3.0, OS10 supports only distributed asymmetric routing mode.
For a sample BGP EVPN routing configuration, see Example: VXLAN with BGP EVPN.
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VXLAN