Arista EOS¶

The Arista EOS implementation supports two modes for BUM (Broadcast, Unknown unicast, Multicast) traffic replication: ingress-replication (default) and multicast.

Configuration Parameters¶

ngs_vxlan_interface - VXLAN interface name (default: Vxlan1)
ngs_bgp_asn - BGP AS number (required)
ngs_evpn_route_target - Route-target value (default: auto)
ngs_bum_replication_mode - BUM traffic replication mode (default: ingress-replication). Options: ingress-replication, multicast
ngs_mcast_group_map - Explicit VNI-to-multicast-group mappings as comma-separated VNI:group pairs. Used for pre-existing multicast group assignments. Example: 10100:239.1.1.100, 10200:239.1.1.200
ngs_mcast_group_base - Base ASM multicast group address for automatic derivation of unmapped VNIs (optional when ngs_mcast_group_map is used, required otherwise when ngs_bum_replication_mode=multicast). Example: 239.1.1.0
ngs_mcast_group_increment - Multicast group derivation method (default: vni_last_octet)

Configuration Examples¶

Ingress-Replication Mode (Default)

[genericswitch:arista-switch]
device_type = netmiko_arista_eos
ip = 192.0.2.30
username = admin
password = password
ngs_physical_networks = datacenter1,datacenter2
ngs_vxlan_interface = Vxlan1
ngs_bgp_asn = 65000

Multicast Mode with Base IP

[genericswitch:arista-leaf02]
device_type = netmiko_arista_eos
ip = 192.0.2.31
username = admin
password = password
ngs_physical_networks = datacenter1,datacenter2
ngs_bum_replication_mode = multicast
ngs_mcast_group_base = 239.1.1.0
ngs_vxlan_interface = Vxlan1
ngs_bgp_asn = 65000

Multicast Mode with Explicit Mapping

[genericswitch:arista-leaf03]
device_type = netmiko_arista_eos
ip = 192.0.2.32
username = admin
password = password
ngs_physical_networks = datacenter1,datacenter2
ngs_bum_replication_mode = multicast
ngs_mcast_group_map = 10100:239.1.1.100, 10200:239.1.1.200
ngs_mcast_group_base = 239.1.1.0
ngs_bgp_asn = 65000

Prerequisites¶

Both modes require BGP EVPN configured and a VXLAN interface configured as a VTEP.

Ingress-Replication Mode¶

Example switch configuration:

! Configure BGP EVPN
router bgp 65000
  router-id 10.0.0.1
  neighbor 10.0.0.2 remote-as 65000
  neighbor 10.0.0.2 update-source Loopback0
  address-family evpn
    neighbor 10.0.0.2 activate

! Configure VXLAN interface
interface Vxlan1
  vxlan source-interface Loopback0
  vxlan udp-port 4789

Multicast Mode¶

For multicast mode, in addition to BGP EVPN (used for MAC/IP learning), your fabric must have PIM Sparse Mode with Anycast RP configured.

Example switch configuration:

! Configure PIM on underlay interfaces
interface Ethernet1-48
  ip pim sparse-mode

! Loopback for VTEP
interface Loopback0
  ip address 10.0.0.1/32
  ip pim sparse-mode

! Anycast RP configuration
ip pim rp-address 10.255.255.254 239.0.0.0/8

! Configure Anycast RP set
ip pim anycast-rp 10.255.255.254 10.0.0.1
ip pim anycast-rp 10.255.255.254 10.0.0.2

! Configure BGP EVPN (for MAC/IP learning)
router bgp 65000
  router-id 10.0.0.1
  neighbor 10.0.0.2 remote-as 65000
  neighbor 10.0.0.2 update-source Loopback0
  address-family evpn
    neighbor 10.0.0.2 activate

! Configure VXLAN interface
interface Vxlan1
  vxlan source-interface Loopback0
  vxlan udp-port 4789

Generated Configuration¶

For each VXLAN network, the driver automatically generates the following configuration on the switch.

Ingress-Replication Mode:

! BGP EVPN control plane
router bgp 65000
  vlan 100
    rd auto
    route-target both auto

! Data plane with ingress-replication
interface Vxlan1
  vxlan vlan 100 vni 10100

Multicast Mode:

! BGP EVPN control plane (MAC/IP learning only)
router bgp 65000
  vlan 100
    rd auto
    route-target both auto

! Data plane with multicast group
interface Vxlan1
  vxlan vlan 100 vni 10100
  vxlan vlan 100 flood vtep 239.1.1.116

Arista EOS