Connectivity Guide

You can auto-generate or manually configure the RT import and export for each EVI. In auto-EVI mode, RT auto-generates. In
manual EVI configuration mode, you can auto-generate or manually configure the RT.
The RT consists of a 2-octet type and a 6-octet value. If you auto-configure a RT, the encoding format is different for a 2-byte
and 4-byte AS number (ASN):
● For a 2-byte ASN, the RT type is set to 0200 (Type 0 in RFC 4364). The RT value is encoded in the format described in
section 5.1.2.1 of RFC 8365: 2-octet-ASN: 4-octet-number, where the following values are used in the 4-octet-number field:
○ Type: 1
○ D-ID: 0
○ Service-ID: VNI
● For a 4-byte ASN, OS10 can auto-configure RTs for both 2-byte and 4-byte ASNs. The RT type is set to 0202 (Type 2 in
RFC 4364). The RT value is encoded in the format: 4-octet-ASN: 2-octet-number, where the 2-octet-number field contains
the EVI ID. In auto-EVI mode, the EVI ID is the same as the virtual network ID (VNID). Therefore, in 4-byte ASN deployment,
OS10 supports RT auto-configuration if the VNID-to-VNI mapping is the same on all VTEPs.
Configure BGP EVPN for VXLAN
To set up BGP EVPN service in a VXLAN overlay network:
1. Configure the VXLAN overlay network. If you enable routing for VXLAN virtual networks, Integrated Routing and Bridging
(IRB) for BGP EVPN is automatically enabled. For more information, see Configure VXLAN.
2. Configure BGP to advertise EVPN routes.
3. Configure EVPN, including the VNI, RD, and RT values associated with the EVPN instance.
4. Verify the BGP EVPN configuration.
Usage guidelines
● Only L2 gateway EVPN bridging functionality is supported.
● Only EVPN route types 2 and 3 are supported.
● Only asymmetric IRB is supported.
Configuration
1. Configure BGP to advertise EVPN routes.
EVPN requires that you establish MP-BGP sessions between leaf and spine nodes in the underlay network. On each spine
and leaf node, configure at least two BGP peering sessions:
● A directly connected BGP peer in the underlay network to advertise VTEP and Loopback IP addresses using the IPv4
unicast address family.
● A BGP peer in the overlay network to advertise overlay information using the EVPN address family. In BGP peer sessions
in the overlay, activate only the EVPN address family.
For each BGP peer session in the underlay network:
a. Create a BGP instance in CONFIGURATION mode. You enter router BGP configuration mode.
router bgp as-number
b. Assign an IP address to the BGP instance in ROUTER-BGP mode.
router-id ip-address
c. Enter IPv4 address-family configuration mode from ROUTER-BGP mode.
address-family ipv4 unicast
d. Advertise the IPv4 prefix to BGP peers in the address family in ROUTER-BGP-ADDRESS-FAMILY mode.
network ip-address/mask
e. Return to ROUTER-BGP mode.
exit
f. Configure the BGP peer address in ROUTER-BGP mode.
neighbor ip-address
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VXLAN