Configuring VXLAN BGP EVPN

This chapter contains the following sections:

About VXLAN BGP EVPN

About RD Auto

The auto-derived Route Distinguisher (rd auto) is based on the Type 1 encoding format as described in IETF RFC 4364 section 4.2 https://tools.ietf.org/html/rfc4364#section-4.2. The Type 1 encoding allows a 4-byte administrative field and a 2-byte numbering field. Within Cisco NX-OS, the auto derived RD is constructed with the IP address of the BGP Router ID as the 4-byte administrative field (RID) and the internal VRF identifier for the 2-byte numbering field (VRF ID).

The 2-byte numbering field is always derived from the VRF, but results in a different numbering scheme depending on its use for the IP-VRF or the MAC-VRF:

  • The 2-byte numbering field for the IP-VRF uses the internal VRF ID starting at 1 and increments. VRF IDs 1 and 2 are reserved for the default VRF and the management VRF respectively. The first custom defined IP VRF uses VRF ID 3.

  • The 2-byte numbering field for the MAC-VRF uses the VLAN ID + 32767, which results in 32768 for VLAN ID 1 and incrementing.

Example auto-derived Route Distinguisher (RD)

  • IP-VRF with BGP Router ID 192.0.2.1 and VRF ID 6 - RD 192.0.2.1:6

  • MAC-VRF with BGP Router ID 192.0.2.1 and VLAN 20 - RD 192.0.2.1:32787

About Route-Target Auto

The auto-derived Route-Target (route-target import/export/both auto) is based on the Type 0 encoding format as described in IETF RFC 4364 section 4.2 (https://tools.ietf.org/html/rfc4364#section-4.2). IETF RFC 4364 section 4.2 describes the Route Distinguisher format and IETF RFC 4364 section 4.3.1 refers that it is desirable to use a similar format for the Route-Targets. The Type 0 encoding allows a 2-byte administrative field and a 4-byte numbering field. Within Cisco NX-OS, the auto derived Route-Target is constructed with the Autonomous System Number (ASN) as the 2-byte administrative field and the Service Identifier (VNI) for the 4-byte numbering field.

2-byte ASN

The Type 0 encoding allows a 2-byte administrative field and a 4-byte numbering field. Within Cisco NX-OS, the auto-derived Route-Target is constructed with the Autonomous System Number (ASN) as the 2-byte administrative filed and the Service Identifier (VNI) for the 4-byte numbering field.

Examples of an auto derived Route-Target (RT):

  • IP-VRF within ASN 65001 and L3VNI 50001 - Route-Target 65001:50001

  • MAC-VRF within ASN 65001 and L2VNI 30001 - Route-Target 65001:30001

For Multi-AS environments, the Route-Targets must either be statically defined or rewritten to match the ASN portion of the Route-Targets.

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/7-x/command_references/configuration_commands/b_N9K_Config_Commands_703i7x/b_N9K_Config_Commands_703i7x_chapter_010010.html#wp4498893710

4-byte ASN

The Type 0 encoding allows a 2-byte administrative field and a 4-byte numbering field. Within Cisco NX-OS, the auto-derived Route-Target is constructed with the Autonomous System Number (ASN) as the 2-byte administrative filed and the Service Identifier (VNI) for the 4-byte numbering field. With the ASN demand of 4-byte length and the VNI requiring 24-bit (3-bytes), the Sub-Field length within the Extended Community is exhausted (2-byte Type and 6-byte Sub-Field). As a result of the length and format constraint and the importance of the Service Identifiers (VNI) uniqueness, the 4-byte ASN is represented in a 2-byte ASN named AS_TRANS, as described in IETF RFC 6793 section 9 (https://tools.ietf.org/html/rfc6793#section-9). The 2-byte ASN 23456 is registered by the IANA (https://www.iana.org/assignments/iana-as-numbers-special-registry/iana-as-numbers-special-registry.xhtml) as AS_TRANS, a special purpose AS number that aliases 4-byte ASNs.

Example auto derived Route-Target (RT) with 4-byte ASN (AS_TRANS):

  • IP-VRF within ASN 65656 and L3VNI 50001 - Route-Target 23456:50001

  • MAC-VRF within ASN 65656 and L2VNI 30001 - Route-Target 23456:30001


Note

Beginning with Cisco NX-OS Release 9.2(1), auto derived Route-Target for 4-byte ASN is supported.

Guidelines and Limitations for VXLAN BGP EVPN

VXLAN BGP EVPN has the following guidelines and limitations:

  • The following guidelines and limitations apply to VXLAN/VTEP using BGP EVPN:

    • SPAN source or destination is supported on any port.

    For more information, see the Cisco Nexus 9000 Series NX-OS System Management Configuration Guide, Release 9.3(x).

  • When SVI is enabled on a VTEP (flood and learn, or EVPN) regardless of ARP suppression, make sure that ARP-ETHER TCAM is carved using the hardware access-list tcam region arp-ether 256 double-wide command. This requirement does not apply to Cisco Nexus 9200, 9300-EX, and 9300-FX/FX2 platform switches and Cisco Nexus 9500 platform switches with 9700-EX/FX line cards.

  • For the Cisco Nexus 9504 and 9508 with R-series line cards, VXLAN EVPN (Layer 2 and Layer 3) is only supported with the 9636C-RX and 96136YC-R line cards.

  • You can configure EVPN over segment routing or MPLS. See the Cisco Nexus 9000 Series NX-OS Label Switching Configuration Guide, Release 9.3(x) for more information.

  • You can use MPLS tunnel encapsulation using the new CLI encapsulation mpls command. You can configure the label allocation mode for the EVPN address family. See the Cisco Nexus 9000 Series NX-OS Label Switching Configuration Guide, Release 9.3(x) for more information.

  • In a VXLAN EVPN setup that has 2K VNI scale configuration, the control plane down time may take more than 200 seconds. To avoid potential BGP flap, extend the graceful restart time to 300 seconds.

  • Starting from Cisco NX-OS Release 9.3(5), new VXLAN uplink capabilities are introduced:

    • A physical interface in default VRF is supported as VXLAN uplink.

    • A parent interface in default VRF, carrying subinterfaces with VRF and dot1q tags, is supported as VXLAN uplink.

    • A subinterface in any VRF and/or with dot1q tag remains not supported as VXLAN uplink.

    • An SVI in any VRF remains not supported as VXLAN uplink.

    • In vPC with physical peer-link, a SVI can be leveraged as backup underlay, default VRF only between the vPC members (infra-VLAN, system nve infra-vlans).

    • On a vPC pair, shutting down NVE or NVE loopback on one of the vPC nodes is not a supported configuration. This means that traffic failover on one-side NVE shut or one-side loopback shut is not supported.

    • FEX host interfaces remain not supported as VXLAN uplink and cannot have VTEPs connected (BUD node).

  • In a VXLAN EVPN setup, border nodes must be configured with unique route distinguishers, preferably using the auto rd command. Not using unique route distinguishers across all border nodes is not supported. The use of unique route distinguishers is strongly recommended for all VTEPs of a fabric.

  • ARP suppression is only supported for a VNI if the VTEP hosts the First-Hop Gateway (Distributed Anycast Gateway) for this VNI. The VTEP and the SVI for this VLAN have to be properly configured for the distributed Anycast Gateway operation, for example, global Anycast Gateway MAC address configured and Anycast Gateway feature with the virtual IP address on the SVI.

  • The ARP suppression setting must match across the entire fabric. For a specific VNID, all VTEPs must be either configured or not configured.

  • Mobility Sequence number of a locally originated type-2 route (MAC/MAC-IP) can be mismatched between vPC peers, with one vTEP having a sequence number K while other vTEP in the same complex can have the same route with sequence number 0. This does not cause any functional impact and the traffic is not impacted even after the host moves.

  • DHCP snooping (Dynamic Host Configuration Protocol snooping) is not supported on VXLAN VLANs.

  • RACLs are not supported on VXLAN uplink interfaces. VACLs are not supported on VXLAN de-capsulated traffic in egress direction; this applies for the inner traffic coming from network (VXLAN) towards the access (Ethernet).

    As a best practice, always use PACLs/VACLs for the access (Ethernet) to the network (VXLAN) direction. See the Cisco Nexus 9000 Series NX-OS Security Configuration Guide, Release 9.3(x) for other guidelines and limitations for the VXLAN ACL feature.

  • The Cisco Nexus 9000 QoS buffer-boost feature is not applicable for VXLAN traffic.

  • On Cisco Nexus 9000 PX/TX/PQ switches configured as VXLAN VTEPs, if any ALE 40G port is used as a VXLAN underlay port, configuring subinterfaces on either this or any other 40G port is not allowed and could lead to VXLAN traffic loss.

  • For SVI-related triggers (such as shut/unshut or PIM enable/disable), a 30-second delay was added, allowing the Multicast FIB (MFIB) Distribution module (MFDM) to clear the hardware table before toggling between L2 and L3 modes or vice versa.

  • For VXLAN BGP EVPN fabrics with EBGP, the following recommendations are applicable:

    • It is recommended to use loopbacks for the EBGP EVPN peering sessions (overlay control-plane).

    • It is a best practice to use the physical interfaces for EBGP IPv4/IPv6 peering sessions (underlay).

  • Bind the NVE source-interface to a dedicated loopback interface and do not share this loopback with any function or peerings of Layer-3 protocols. A best practice is to use a dedicated loopback address for the VXLAN VTEP function.

  • You must bind NVE to a loopback address that is separate from other loopback addresses that are required by Layer 3 protocols. NVE and other Layer 3 protocols using the same loopback is not supported.

  • The NVE source-interface loopback is required to be present in the default VRF.

  • Only EBGP peering between a VTEP and external nodes (Edge Router, Core Router or VNF) is supported.

    • EBGP peering from the VTEP to the external node using a physical interface or subinterfaces is recommended and it is a best practice (external connectivity).

    • The EBGP peering from the VTEP to the external node can be in the default VRF or in a tenant VRF (external connectivity).

    • The EBGP peering from the VTEP to a external node over VXLAN must be in a tenant VRF and must use the update-source of a loopback interface (peering over VXLAN).

    • Using an SVI for EBGP peering on a from the VTEP to the External Node requires the VLAN to be local (not VXLAN extended).

  • When configuring VXLAN BGP EVPN, only the "System Routing Mode: Default" is applicable for the following hardware platforms:

    • Cisco Nexus 9300 platform switches

    • Cisco Nexus 9300-EX platform switches

    • Cisco Nexus 9300-FX/FX2 platform switches

    • Cisco Nexus 9500 platform switches with X9500 line cards

    • Cisco Nexus 9500 platform switches with X9700-EX and X9700-FX line cards

  • Changing the “System Routing Mode” requires a reload of the switch.

  • Cisco Nexus 9516 platform is not supported for VXLAN EVPN.

  • VXLAN is supported on Cisco Nexus 9500 platform switches with the following line cards:

    • 9500-R

    • 9564PX

    • 9564TX

    • 9536PQ

    • 9700-EX

    • 9700-FX

  • Cisco Nexus 9500 platform switches with 9700-EX or -FX line cards support 1G, 10G, 25G, 40G, 100G and 400G for VXLAN uplinks.

  • Cisco Nexus 9200 and 9300-EX/FX/FX2/FX3 and -GX support 1G, 10G, 25G, 40G, 100G and 400G for VXLAN uplinks.

  • The Cisco Nexus 9000 platform switches use standards conforming UDP port number 4789 for VXLAN encapsulation. This value is not configurable.

  • The Cisco Nexus 9200 platform switches with Application Spine Engine (ASE2) have throughput constrains for packet sizes of 99-122 bytes; packet drops might be experienced.

  • The VXLAN network identifier (VNID) 16777215 is reserved and should explicitly not be configured.

  • Non-Disruptive In Service Software Upgrade (ND-ISSU) is supported on Nexus 9300 with VXLAN enabled. Exception is ND-ISSU support for Cisco Nexus 9300-FX3 and 9300-GX platform switch.

  • Gateway functionality for VXLAN to MPLS (LDP), VXLAN to MPLS-SR (Segment Routing) and VXLAN to SRv6 can be operated on the same Cisco Nexus 9000 Series platform.

    • VXLAN to MPLS (LDP) Gateway is supported on the Cisco Nexus 3600-R and the Cisco Nexus 9500 with R-Series line cards.

    • VXLAN to MPLS-SR Gateway is supported on the Cisco Nexus 9300-FX2/FX3/GX and Cisco Nexus 9500 with R-Series line cards.

    • VXLAN to SRv6 is supported on the Cisco Nexus 9300-GX platform.

    • Multiple Tunnel Encapsulations (VXLAN, GRE and/or MPLS, static label or segment routing) can not co-exist on the same Cisco Nexus 9000 Series switch with Network Forwarding Engine (NFE).

  • Resilient hashing is supported on the following switch platform with a VXLAN VTEP configured:

    • Cisco Nexus 9300-EX/FX/FX2/FX3/GX support ECMP resilient hashing.

    • Cisco Nexus 9300 with ALE uplink ports does not support resilient hashing.


    Note

    Resilient hashing is disabled by default.

  • It is recommended to use the vpc orphan-ports suspend command for single attached and/or routed devices on a Cisco Nexus 9000 platform switch acting as vPC VTEP.


Note

For information about VXLAN BGP EVPN scalability, see the Cisco Nexus 9000 Series NX-OS Verified Scalability Guide.

Configuring VXLAN BGP EVPN

Enabling VXLAN

Enable VXLAN and the EVPN.

Procedure

  Command or Action Purpose

Step 1

feature vn-segment

Enable VLAN-based VXLAN

Step 2

feature nv overlay

Enable VXLAN

Step 3

feature vn-segment-vlan-based

Enable VN-Segment for VLANs.

Step 4

feature interface-vlan

Enable Switch Virtual Interface (SVI).

Step 5

nv overlay evpn

Enable the EVPN control plane for VXLAN.

Configuring VLAN and VXLAN VNI


Note

Step 3 to Step 6 are optional for configuring the VLAN for VXLAN VNI and are only necessary in case of a custom route distinguisher or route-target requirement (not using auto derivation).

Procedure

  Command or Action Purpose

Step 1

vlan number

Specify VLAN.

Step 2

vn-segment number

Map VLAN to VXLAN VNI to configure Layer 2 VNI under VXLAN VLAN.

Step 3

evpn

Enter EVI (EVPN Virtual Instance) configuration mode.

Step 4

vni number l2

Specify the Service Instance (VNI) for the EVI.

Step 5

rd auto

Specify the MAC-VRF's route distinguisher (RD).

Step 6

route-target both {auto | rt}

Configure the route target (RT) for import and export of MAC prefixes. The RT is used for a per-MAC-VRF prefix import/export policy. If you enter an RT, the following formats are supported: ASN2:NN, ASN4:NN, or IPV4:NN.

Note

 

Specifying the auto option is applicable only for IBGP.

Manually configured route targets are required for EBGP and for asymmetric VNIs.

Configuring VRF for VXLAN Routing

Configure the tenant VRF.


Note

Step 3 to step 6 are optional for configuring the VRF for VXLAN Routing and are only necessary in case of a custom route distinguisher or route-target requirement (not using auto derivation).

Procedure

  Command or Action Purpose

Step 1

vrf context vrf-name

Configure the VRF.

Step 2

vni number

Specify the VNI.

Step 3

rd auto

Specify the IP-VRF's route distinguisher (RD).

Step 4

address-family {ipv4 | ipv6} unicast

Configure the IPv4 or IPv6 unicast address family.

Step 5

route-target both {auto | rt}

Configure the route target (RT) for import and export of IPv4 or IPv6 prefixes. The RT is used for a per-IP-VRF prefix import/export policy. If you enter an RT, the following formats are supported: ASN2:NN, ASN4:NN, or IPV4:NN.

Note

 

Specifying the auto option is applicable only for IBGP.

Manually configured route targets are required for EBGP.

Step 6

route-target both {auto | rt} evpn

Configure the route target (RT) for import and export of IPv4 or IPv6 prefixes. The RT is used for a per-VRF prefix import/export policy. If you enter an RT, the following formats are supported: ASN2:NN, ASN4:NN, or IPV4:NN.

Note

 

Specifying the auto option is applicable only for IBGP.

Manually configured route targets are required for EBGP.

Configuring SVI for Core-facing VXLAN Routing

Configure the core-facing SVI VRF.

Procedure

  Command or Action Purpose

Step 1

vlan number

Specify VLAN.

Step 2

vn-segment number

Map VLAN to VXLAN VNI to configure Layer 3 VNI under VXLAN VLAN.

Step 3

interface vlan-number

Specify VLAN interface.

Step 4

mtu vlan-number

MTU size in bytes <68-9216>.

Step 5

vrf member vrf-name

Assign to VRF.

Step 6

no {ip |ipv6} redirects

Disable sending IP redirect messages for IPv4 and IPv6.

Step 7

ip forward

Enable IPv4 based lookup even when the interface VLAN has no IP address defined.

Step 8

ipv6 address use-link-local-only

Enable IPv6 forwarding.

Note

 

The IPv6 address use-link-local-only serves the same purpose as ip forward for IPv4. It enables the switch to perform an IP based lookup even when the interface VLAN has no IP address defined under it.

Configuring SVI for Host-Facing VXLAN Routing

Configure the SVI for hosts, acting as Distributed Default Gateway.

Procedure

  Command or Action Purpose

Step 1

fabric forwarding anycast-gateway-mac address

Configure distributed gateway virtual MAC address.

Note

 

One virtual MAC per VTEP.

Note

 

All VTEPs should have the same virtual MAC address.

Step 2

vlan number

Specify VLAN.

Step 3

vn-segment number

Specify vn-segment.

Step 4

interface vlan-number

Specify VLAN interface.

Step 5

vrf member vrf-name

Assign to VRF.

Step 6

ip address address

Specify IP address.

Step 7

fabric forwarding mode anycast-gateway

Associate SVI with anycast gateway under VLAN configuration mode.

Configuring the NVE Interface and VNIs Using Multicast

Procedure

  Command or Action Purpose

Step 1

interface nve-interface

Configure the NVE interface.

Step 2

source-interface loopback1

Binds the NVE source-interface to a dedicated loopback interface.

Step 3

host-reachability protocol bgp

This defines BGP as the mechanism for host reachability advertisement

Step 4

global mcast-group ip-address {L2 | L3}

Configures the mcast group globally (for all VNI) on a per-NVE interface basis. This applies and gets inherited s to all Layer 2 or Layer 3 VNIs.

Note

 

Layer3 macst group is only used for Tenant Routed Multicast (TRM).

Step 5

member vni vni

Add Layer 2 VNIs to the tunnel interface.

Step 6

mcast-group ip address

Configure the mcast group on a per-VNI basis. Add Layer 2 VNI specific mcast group and override the global set configuration.

Note

 

Instead of a mcast group, ingress replication can be configured.

Step 7

member vni vni associate-vrf

Add Layer-3 VNIs, one per tenant VRF, to the overlay.

Note

 

Required for VXLAN routing only.

Step 8

mcast-group address

Configure the mcast group on a per-VNI basis. Add Layer 3 VNI specific mcast group and override the global set configuration.

Configuring VXLAN EVPN Ingress Replication

For VXLAN EVPN ingress replication, the VXLAN VTEP uses a list of IP addresses of other VTEPs in the network to send BUM (broadcast, unknown unicast and multicast) traffic. These IP addresses are exchanged between VTEPs through the BGP EVPN control plane.


Note

VXLAN EVPN ingress replication is supported on:

  • Cisco Nexus Series 9300 Series switches (7.0(3)I1(2) and later).

  • Cisco Nexus Series 9500 Series switches (7.0(3)I2(1) and later).

Before you begin: The following are required before configuring VXLAN EVPN ingress replication (7.0(3)I1(2) and later):

  • Enable VXLAN.

  • Configure VLAN and VXLAN VNI.

  • Configure BGP on the VTEP.

  • Configure RD and Route Targets for VXLAN Bridging.

Procedure

  Command or Action Purpose

Step 1

interface nve-interface

Configure the NVE interface.

Step 2

host-reachability protocol bgp

This defines BGP as the mechanism for host reachability advertisement.

Step 3

global ingress-replication protocol bgp

Enables globally (for all VNI) the VTEP to exchange local and remote VTEP IP addresses on the VNI in order to create the ingress replication list. This enables sending and receiving BUM traffic for the VNI.

Note

 

Using ingress-replication protocol bgp avoids the need for any multicast configurations that might have been required for configuring the underlay.

Step 4

member vni vni associate-vrf

Add Layer-3 VNIs, one per tenant VRF, to the overlay.

Note

 

Required for VXLAN routing only.

Step 5

member vni vni

Add Layer 2 VNIs to the tunnel interface.

Step 6

ingress-replication protocol bgp

Enables the VTEP to exchange local and remote VTEP IP addresses on a oer VNI basis in order to create the ingress replication list. This enables sending and receiving BUM traffic for the VNI and override the global configuration.

Note

 

Instead of a ingress replication, mcast group can be configured.

Note

 

Using ingress-replication protocol bgp avoids the need for any multicast configurations that might have been required for configuring the underlay.

Configuring BGP on the VTEP

Procedure

  Command or Action Purpose

Step 1

router bgp number

Configure BGP.

Step 2

router-id address

Specify router address.

Step 3

neighbor address remote-as number

Define MPBGP neighbors. Under each neighbor define L2VPN EVPN.

Step 4

address-family l2vpn evpn

Configure address family Layer 2 VPN EVPN under the BGP neighbor.

Note

 

Address-family IPv4 EVPN for VXLAN host-based routing

Step 5

(Optional) Allowas-in

(Optional)

Only for EBGP deployment cases: Allows duplicate autonomous system (AS) numbers in the AS path. Configure this parameter on the leaf for eBGP when all leafs are using the same AS, but the spines have a different AS than leafs.

Step 6

send-community extended

Configures community for BGP neighbors.

Step 7

vrf vrf-name

Specify VRF.

Step 8

address-family ipv4 unicast

Configure the address family for IPv4.

Step 9

maximum-paths path {ibgp}

Enable ECMP for EVPN transported IP Prefixes within the IPv6 address-family of the respective VRF.

Step 10

address-family ipv6 unicast

Configure the address family for IPv6.

Step 11

maximum-paths path {ibgp}

Enable ECMP for EVPN transported IP Prefixes within the IPv6 address-family of the respective VRF.

Configuring iBGP for EVPN on the Spine

Procedure

  Command or Action Purpose

Step 1

router bgp autonomous system number

Specify BGP.

Step 2

neighbor address remote-as number

Define neighbor.

Step 3

address-family l2vpn evpn

Configure address family Layer 2 VPN EVPN under the BGP neighbor.

Step 4

send-community extended

Configures community for BGP neighbors.

Step 5

route-reflector-client

Enable Spine as Route Reflector.

Step 6

retain route-target all

Configure retain route-target all under address-family Layer 2 VPN EVPN [global].

Note

 

Required for eBGP. Allows the spine to retain and advertise all EVPN routes when there are no local VNI configured with matching import route targets.

Step 7

address-family l2vpn evpn

Configure address family Layer 2 VPN EVPN under the BGP neighbor.

Step 8

disable-peer-as-check

Disables checking the peer AS number during route advertisement. Configure this parameter on the spine for eBGP when all leafs are using the same AS but the spines have a different AS than leafs.

Note

 

Required for eBGP.

Step 9

route-map permitall out

Applies route-map to keep the next-hop unchanged.

Note

 

Required for eBGP.

Configuring eBGP for EVPN on the Spine

Procedure

  Command or Action Purpose

Step 1

route-map NEXT-HOP-UNCH permit 10

Configure route-map to keepthe next-hop unchanged for EVPN routes.

Step 2

set ip next-hop unchanged

Set next-hop address.

Note

 

When two next hops are enabled, next hop ordering is not maintained.

If one of the next hops is a VXLAN next hop and the other next hop is local reachable via FIB/AM/Hmm, the local next hop reachable via FIB/AM/Hmm is always taken irrespective of the order.

Directly/locally connected next hops are always given priority over remotely connected next hops.

Step 3

router bgp autonomous system number

Specify BGP.

Step 4

address-family l2vpn evpn

Configure address family Layer 2 VPN EVPN under the BGP neighbor.

Step 5

retain route-target all

Configure retain route-target all under address-family Layer 2 VPN EVPN [global].

Note

 

Required for eBGP. Allows the spine to retain and advertise all EVPN routes when there are no local VNI configured with matching import route targets.

Step 6

neighbor address remote-as number

Define neighbor.

Step 7

address-family l2vpn evpn

Configure address family Layer 2 VPN EVPN under the BGP neighbor.

Step 8

disable-peer-as-check

Disables checking the peer AS number during route advertisement. Configure this parameter on the spine for eBGP when all leafs are using the same AS but the spines have a different AS than leafs.

Step 9

send-community extended

Configures community for BGP neighbors.

Step 10

route-map NEXT-HOP-UNCH out

Applies route-map to keep the next-hop unchanged.

Suppressing ARP

Suppressing ARP includes changing the size of the ACL ternary content addressable memory (TCAM) regions in the hardware.


Note

For information on configuring ACL TCAM regions, see the Configuring IP ACLs chapter of the Cisco Nexus 9000 Series NX-OS Security Configuration Guide.

Procedure

  Command or Action Purpose

Step 1

hardware access-list tcam region arp-ether size double-wide

Configure TCAM region to suppress ARP.

tcam-size —TCAM size. The size has to be a multiple of 256. If the size is more than 256, it has to be a multiple of 512.

Note

 

Reload is required for the TCAM configuration to be in effect.

Note

 

Configuring the hardware access-list tcam region arp-ether size double-wide command is not required for Cisco Nexus 9200, 9300-EX, and 9300-FX/FX2 platform switches.

Step 2

interface nve 1

Create the network virtualization endpoint (NVE) interface.

Step 3

global suppress-arp

Configure to suppress ARP globally for all Layer 2 VNI.within the NVE interface.

Step 4

member vni vni-id

Specify VNI ID.

Step 5

suppress-arp

Configure to suppress ARP under Layer 2 VNI and overrides the global set default.

Step 6

suppress-arp disable

Disables the global setting of the ARP suppression on a specific VNI.

Disabling VXLANs

Procedure

  Command or Action Purpose

Step 1

configure terminal

Enters configuration mode.

Step 2

no nv overlay evpn

Disables EVPN control plane.

Step 3

no feature vn-segment-vlan-based

Disables the global mode for all VXLAN bridge domains

Step 4

no feature nv overlay

Disables the VXLAN feature.

Step 5

(Optional) copy running-config startup-config

(Optional)

Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration.

Duplicate Detection for IP and MAC Addresses

For IP addresses:

Cisco NX-OS supports duplicate detection for IP addresses. This enables the detection of duplicate IP addresses based on the number of moves in a given time-interval (seconds), if host appears simultaneously under two VTEP’s.

Simultaneous availability of host under two VTEP’s is detected by host mobility logic with 600 msec refresh timeout for IPv4 hosts and default refresh time out logic for IPv6 addresses (default is 3 seconds).

The default is 5 moves in 180 seconds. (Default number of moves is 5 moves. Default time-interval is 180 seconds.)

After the 5th move within 180 seconds, the switch starts a 30 second lock (hold down timer) before checking to see if the duplication still exists (an effort to prevent an increment of the sequence bit). This 30 second lock can occur 5 times within 24 hours (this means 5 moves in 180 seconds for 5 times) before the switch permanently locks or freezes the duplicate entry. (show fabric forwarding ip local-host-db vrf abc )

Wherever a host IP address is permanently frozen, a syslog message is written by HMM. 
2021 Aug 26 01:08:26 leaf hmm: (vrf-name) [IPv4] Freezing potential duplicate host 20.2.0.30/32, reached recover count (5) threshold

The following are example commands to help the configuration of the number of VM moves in a specific time interval (seconds) for duplicate IP-detection:

Command

Description 


switch(config)# fabric forwarding ?
      anycast-gateway-mac 
      dup-host-ip-addr-detection

Available sub-commands:

  • Anycast gateway MAC of the switch.

  • To detect duplicate host addresses in n seconds. 


switch(config)# fabric forwarding dup-host-ip-addr-detection ?
      <1-1000>

The number of host moves allowed in n seconds. The range is 1 to 1000 moves; default is 5 moves. 

    
switch(config)# fabric forwarding dup-host-ip-addr-detection 100 ?
      <2-36000>

The duplicate detection timeout in seconds for the number of host moves. The range is 2 to 36000 seconds; default is 180 seconds. 

    
switch(config)# fabric forwarding dup-host-ip-addr-detection 100 10

Detects duplicate host addresses (limited to 100 moves) in a period of 10 seconds.

For MAC addresses:

Cisco NX-OS supports duplicate detection for MAC addresses. This enables the detection of duplicate MAC addresses based on the number of moves in a given time-interval (seconds).

The default is 5 moves in 180 seconds. (Default number of moves is 5 moves. Default time-interval is 180 seconds.)

After the 5th move within 180 seconds, the switch starts a 30 second lock (hold down timer) before checking to see if the duplication still exists (an effort to prevent an increment of the sequence bit). This 30 second lock can occur 3 times within 24 hours (this means 5 moves in 180 seconds for 3 times) before the switch permanently locks or freezes the duplicate entry. (show l2rib internal permanently-frozen-list )

Wherever a MAC address is permanently frozen, a syslog message with written by L2RIB. 


2017 Jul  5 10:27:34 leaf %$ VDC-1 %$  %USER-2-SYSTEM_MSG: Unfreeze limit (3) hit, MAC 0000.0033.3333in topo: 200 is permanently frozen - l2rib
2017 Jul  5 10:27:34 leaf %$ VDC-1 %$  %USER-2-SYSTEM_MSG: Detected duplicate host 0000.0033.3333, topology 200, during Local update, with host located at remote VTEP 1.2.3.4, VNI 2 - l2rib 
2017 Jul  5 10:27:34 leaf %$ VDC-1 %$  %USER-2-SYSTEM_MSG: Unfreeze limit (3) hit, MAC 0000.0033.3334in topo: 200 is permanently frozen - l2rib        
2017 Jul  5 10:27:34 leaf %$ VDC-1 %$  %USER-2-SYSTEM_MSG: Detected duplicate host 0000.0033.3334, topology 200, during Local update, with host l

MAC address remains in permanently frozen list until both local and remote entry exists.

Unconfiguring below commands will not disable permanently frozen functionality rather will change the parameters to default values.

  • l2rib dup-host-mac-detection

  • l2rib dup-host-recovery

The following are example commands to help the configuration of the number of VM moves in a specific time interval (seconds) for duplicate MAC-detection:

Command

Description 


 switch(config)# l2rib dup-host-mac-detection ?
      <1-1000>  
      default

Available sub-commands for L2RIB:

  • The number of host moves allowed in n seconds. The range is 1 to 1000 moves.

  • Default setting (5 moves in 180 in seconds). 


 switch(config)# l2rib dup-host-mac-detection 100 ?
      <2-36000>

The duplicate detection timeout in seconds for the number of host moves. The range is 2 to 36000 seconds; default is 180 seconds. 

    
switch(config)# l2rib dup-host-mac-detection 100 10

Detects duplicate host addresses (limited to 100 moves) in a period of 10 seconds.

Verifying the VXLAN BGP EVPN Configuration

To display the VXLAN BGP EVPN configuration information, enter one of the following commands:

Command

Purpose

show nve vrf

Displays VRFs and associated VNIs

show bgp l2vpn evpn

Displays routing table information.

show ip arp suppression-cache [detail | summary | vlan vlan | statistics ]

Displays ARP suppression information.

show vxlan interface

Displays VXLAN interface status.

show vxlan interface | count

Displays VXLAN VLAN logical port VP count.

Note

 

A VP is allocated on a per-port per-VLAN basis. The sum of all VPs across all VXLAN-enabled Layer 2 ports gives the total logical port VP count. For example, if there are 10 Layer 2 trunk interfaces, each with 10 VXLAN VLANs, then the total VXLAN VLAN logical port VP count is 10*10 = 100.

show l2route evpn mac [all | evi evi [bgp | local | static | vxlan | arp]]

Displays Layer 2 route information.

show l2route evpn fl all

Displays all fl routes.

show l2route evpn imet all

Displays all imet routes.

show l2route evpn mac-ip all

show l2route evpn mac-ip all detail

Displays all MAC IP routes.

show l2route topology

Displays Layer 2 route topology.


Note

Although the show ip bgp command is available for verifying a BGP configuration, as a best practice, it is preferable to use the show bgp command instead.

Example of VXLAN BGP EVPN (IBGP)

An example of a VXLAN BGP EVPN (IBGP):

Figure 1. VXLAN BGP EVPN Topology (IBGP)


IBGP between Spine and Leaf

  • Spine (9504-A)

    • Enable the EVPN control plane 

      nv overlay evpn

    • Enable the relevant protocols 

      
feature ospf
feature bgp
feature pim

    • Configure Loopback for local Router ID, PIM, and BGP 

      
interface loopback0
  ip address 10.1.1.1/32
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode

    • Configure Loopback for Anycast RP 

      
interface loopback1
  ip address 100.1.1.1/32
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode

    • Configure Anycast RP 

      

ip pim rp-address 100.1.1.1 group-list 224.0.0.0/4
ip pim anycast-rp 100.1.1.1 10.1.1.1
ip pim anycast-rp 100.1.1.1 20.1.1.1

    • Enable OSPF for underlay routing 

      
router ospf 1

    • Configure interfaces for Spine-leaf interconnect 

      
interface Ethernet4/2
  ip address 192.168.1.42/24
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode
  no shutdown
 
interface Ethernet4/3
  ip address 192.168.2.43/24
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode
  no shutdown

    • Configure BGP 

      
router bgp 65535
router-id 10.1.1.1
  neighbor 30.1.1.1 remote-as 65535
    update-source loopback0
    address-family l2vpn evpn
      send-community both
      route-reflector-client
  neighbor 40.1.1.1 remote-as 65535
    update-source loopback0
    address-family l2vpn evpn
      send-community both
      route-reflector-client

  • Spine (9504-B)

    • Enable the EVPN control plane 

      

nv overlay evpn

    • Enable the relevnt Protocols

      
feature ospf
feature bgp
feature pim

    • Configure Loopback for local Router ID, PIM, and BGP

      interface loopback0
  ip address 20.1.1.1/32
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode

    • Configure Loopback for AnycastRP

      interface loopback1
  ip address 100.1.1.1/32
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode

    • Configure Anycast RP 

      

ip pim rp-address 100.1.1.1 group-list 224.0.0.0/4
ip pim anycast-rp 100.1.1.1 10.1.1.1
ip pim anycast-rp 100.1.1.1 20.1.1.1

    • Enable OSPF for underlayrouting

      router ospf 1

    • Configure interfaces for Spine-leaf interconnect 

      interface Ethernet4/2
  ip address 192.168.3.42/24
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode
  no shutdown

interface Ethernet4/3
  ip address 192.168.4.43/24
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode
  no shutdown

    • Configure BGP 

      router bgp 65535
  router-id 20.1.1.1
  neighbor 30.1.1.1 remote-as 65535
    update-source loopback0
    address-family l2vpn evpn
      send-community both
      route-reflector client
  neighbor 40.1.1.1 remote-as 65535
    update-source loopback0
    address-family l2vpn evpn
      send-community both
      route-reflector client

  • Leaf (9396-A)

    • Enable the EVPN control plane 

      
nv overlay evpn

    • Enable the relevant protocols 

      
feature ospf
feature bgp
feature pim
feature interface-vlan

    • Enable VXLAN with distributed anycast-gateway using BGP EVPN 

      
feature vn-segment-vlan-based
feature nv overlay
fabric forwarding anycast-gateway-mac 0000.2222.3333

    • Enabling OSPF for underlay routing 

      
router ospf 1

    • Configure Loopback for local Router ID, PIM, and BGP 

      interface loopback0
  ip address 30.1.1.1/32
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode

    • Configure Loopback for local VTEP IP

      
interface loopback1
  ip address 33.1.1.1/32
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode

    • Configure interfaces for Spine-leaf interconnect 

      
interface Ethernet2/2
  no switchport
  ip address 192.168.1.22/24
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode
  no shutdown

interface Ethernet2/3
  no switchport
  ip address 192.168.3.23/24
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode
  shutdown

    • Configure route-map to Redistribute Host-SVI (Silent Host)

      route-map HOST-SVI permit 10
  match tag 54321

    • Configure PIM RP 

      

ip pim rp-address 100.1.1.1 group-list 224.0.0.0/4

    • Create VLANs

      vlan 1001-1002

    • Create overlay VRF VLAN and configure vn-segment 

      
vlan 101
  vn-segment 900001

    • Create overlay VRF VLAN and configure vn-segment

      

vlan 101
  vn-segment 900001

    • Configure Core-facing SVI for VXLAN routing

      interface vlan101
 no shutdown
  vrf member vxlan-900001
  ip forward
  no ip redirects
  ipv6 address use-link-local-only
  no ipv6 redirects

    • Create VLAN and provide mapping to VXLAN 

      
vlan 1001
  vn-segment 2001001
vlan 1002
  vn-segment 2001002

    • Create VRF and configure VNI 

      
vrf context vxlan-900001
  vni 900001
  rd auto

      Note

      The rd auto and route-target commands are automatically configured unless one or more are entered as overrides. 

      \
address-family ipv4 unicast
      route-target both auto
      route-target both auto evpn
    address-family ipv6 unicast
      route-target both auto
      route-target both auto evpn

    • Create server facing SVI and enable distributed anycast-gateway.

      
interface vlan1001
  no shutdown
  vrf member vxlan-900001
  ip address 4.1.1.1/24 tag 54321
  ipv6 address 4:1:0:1::1/64 tag 54321
  fabric forwarding mode anycast-gateway

interface vlan1002
  no shutdown
  vrf member vxlan-900001
  ip address 4.2.2.1/24 tag 54321
  ipv6 address 4:2:0:1::1/64 tag 54321
  fabric forwarding mode anycast-gateway

    • Configure ACL TCAM region for ARP suppression


      Note

      The hardware access-list tcam region arp-ether 256 double-wide command is not needed for Cisco Nexus 9300-EX and 9300-FX/FX2 platform switches. 

      
hardware access-list tcam region arp-ether 256 double-wide

    • Note

      You can choose either of the following two options for creating the NVE interface. Use Option 1 for a small number of VNIs. Use Option 2 to leverage the simplified configuration mode.

      Create the network virtualization endpoint (NVE) interface

      Option 1

      
interface nve1  
no shutdown
  source-interface loopback1
  host-reachability protocol bgp
  member vni 900001 associate-vrf
  member vni 2001001
    mcast-group 239.0.0.1
  member vni 2001002
    mcast-group 239.0.0.1

      Option 2

      

interface nve1
  source-interface loopback1
  host-reachability protocol bgp
  global mcast-group 239.0.0.1 L2
  member vni 2001001
  member vni 2001002
  member vni 2001007-2001010

    • Configure interfaces for hosts/servers 

      

interface Ethernet1/47
  switchport
  switchport access vlan 1002

interface Ethernet1/48
  switchport
  switchport access vlan 1001

    • Configure BGP 

      
router bgp 65535
  router-id 30.1.1.1
  neighbor 10.1.1.1 remote-as 65535
    update-source loopback0
    address-family l2vpn evpn
      send-community both
  neighbor 20.1.1.1 remote-as 65535
    update-source loopback0
    address-family l2vpn evpn
      send-community both
  vrf vxlan-900001
    address-family ipv4 unicast
      redistribute direct route-map HOST-SVI
    address-family ipv6 unicast
      redistribute direct route-map HOST-SVI

      Note

      The following commands in EVPN mode do not need to be entered. 

      evpn                                         
  vni 2001001 l2
  vni 2001002 l2

      Note

      The rd auto and route-target auto commands are automatically configured unless one or more are entered as overrides. 

      rd auto
    route-target import auto
    route-target export auto

      Note

      The rd auto and route-target commands are automatically configured unless you want to use them to override the import or export options.


      Note

      The following commands in EVPN mode do not need to be entered.

      		 
      
evpn
  vni 2001001 l2
    rd auto
    route-target import auto
    route-target export auto
  vni 2001002 l2
    rd auto
    route-target import auto
    route-target export auto

  • Leaf (9396-B)

    • Enable the EVPN control plane 

      


nv overlay evpn

    • Enable the relevant protocols 

      

feature ospf
feature bgp
feature pim
feature interface-vlan

    • Enable VxLAN with distributed anycast-gateway using BGP EVPN 

      
feature vn-segment-vlan-based
feature nv overlay
fabric forwarding anycast-gateway-mac 0000.2222.3333

    • Enabling OSPF for underlayrouting

      router ospf 1

    • Configure Loopback for local Router ID, PIM, and BGP

      interface loopback0
  ip address 40.1.1.1/32
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode

    • Configure Loopback for local VTEP IP

      
interface loopback1
  ip address 44.1.1.1/32
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode

    • Configure interfaces for Spine-leaf interconnect

      interface Ethernet2/2
  no switchport
  ip address 192.168.3.22/24
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode
  no shutdown

interface Ethernet2/3
  no switchport
  ip address 192.168.4.23/24
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode
  shutdown

    • Configure route-map to Redistribute Host-SVI (Silent Host)

      route-map HOST-SVI permit 10
  match tag 54321

    • Configure PIM RP 

      

ip pim rp-address 100.1.1.1 group-list 224.0.0.0/4

    • Create VLANs

      vlan 1001-1002

    • Create overlay VRF VLAN and configure vn-segment 

      
vlan 101
  vn-segment 900001

    • Configure Core-facing SVI for VXLAN routing

      interface vlan101
 no shutdown
  vrf member vxlan-900001
  ip forward
  no ip redirects
  ipv6 address use-link-local-only
  no ipv6 redirects

    • Create VLAN and provide mapping to VXLAN 

      
vlan 1001
  vn-segment 2001001
vlan 1002
  vn-segment 2001002

    • Create VRF and configure VNI 

      
vrf context vxlan-900001
  vni 900001
  rd auto

      Note

      The rd auto and route-target commands are automatically configured unless one or more are entered as overrides. 

      
  address-family ipv4 unicast
    route-target both auto
    route-target both auto evpn
  address-family ipv6 unicast
    route-target both auto
    route-target both auto evpn

    • Create server facing SVI and enable distributed anycast-gateway

      interface vlan1001
  no shutdown
  vrf member vxlan-900001
  ip address 4.1.1.1/24
  ipv6 address 4:1:0:1::1/64
  fabric forwarding mode anycast-gateway

interface vlan1002
  no shutdown
  vrf member vxlan-900001
  ip address 4.2.2.1/24
  ipv6 address 4:2:0:1::1/64
  fabric forwarding mode anycast-gateway

    • Configure ACL TCAM region for ARP suppression


      Note

      The hardware access-list tcam region arp-ether 256 double-wide command is not needed for Cisco Nexus 9300-EX and 9300-FX/FX2 platform switches. 

      

hardware access-list tcam region arp-ether 256 double-wide

    • Note

      You can choose either of the following two command procedures for creating the NVE interfaces. Use Option 1 for a small number of VNIs. Use Option 2 to leverage the simplified configuration mode.

      Create the network virtualization endpoint (NVE) interface

      Option 1

      

interface nve1
  no shutdown
  source-interface loopback1
  host-reachability protocol bgp
  member vni 900001 associate-vrf
  member vni 2001001
    mcast-group 239.0.0.1
  member vni 2001002
    mcast-group 239.0.0.1

      Option 2

      
interface nve1
  interface nve1
  source-interface loopback1
  host-reachability protocol bgp
  global mcast-group 239.0.0.1 L2
  member vni 2001001
  member vni 2001002
  member vni 2001007-2001010

    • Configure interfaces for hosts/servers 

      

interface Ethernet1/47
  switchport
  switchport access vlan 1002

interface Ethernet1/48
  switchport
  switchport access vlan 1001

    • Configure BGP 

      
router bgp 65535
  router-id 40.1.1.1
  neighbor 10.1.1.1 remote-as 65535
    update-source loopback0
    address-family l2vpn evpn
      send-community both
  neighbor 20.1.1.1 remote-as 65535
    update-source loopback0
    address-family l2vpn evpn
      send-community both
  vrf vxlan-900001
  vrf vxlan-900001
    address-family ipv4 unicast
      redistribute direct route-map HOST-SVI
    address-family ipv6 unicast
      redistribute direct route-map HOST-SVI

      Note

      The following commands in EVPN mode do not need to be entered.

      evpn
  vni 2001001 l2
  vni 2001002 l2

      Note

      The rd auto and route-target commands are automatically configured unless one or more are entered as overrides. 

          
rd auto
    route-target import auto
    route-target export auto

      Note

      The following commands in EVPN mode do not need to be entered.

      evpn
  vni 2001001 l2
    rd auto
    route-target import auto
    route-target export auto
  vni 2001002 l2
    rd auto
    route-target import auto
    route-target export auto

Note

When you have IBGP session between BGWs and EBGP fabric is used, you need to configure the route-map to make VIP or VIP_R route advertisement with higher AS-PATH when local VIP or VIP_R is down (due to reload or fabric link flap). A sample route-map configuration is provided below. In this example 192.0.2.1 is VIP address and 198.51.100.1 is BGP VIP route's nexthop learned from same BGW site. 

ip prefix-list vip_ip seq 5 permit 192.0.2.1/32 
ip prefix-list vip_route_nh seq 5 permit 198.51.100.1/32

route-map vip_ip permit 5
  match ip address prefix-list vip_ip 
  match ip next-hop prefix-list vip_route_nh 
  set as-path prepend 5001 5001 5001 
route-map vip_ip permit 10

Example of VXLAN BGP EVPN (EBGP)

An example of a VXLAN BGP EVPN (EBGP):

Figure 2. VXLAN BGP EVPN Topology (EBGP)


EBGP between Spine and Leaf

  • Spine (9504-A)

    • Enable the EVPN control plane 

      nv overlay evpn

    • Enable the relevant protocols 

      
feature bgp
feature pim

    • Configure Loopback for local Router ID, PIM, and BGP 

      interface loopback0
  ip address 10.1.1.1/32 tag 12345
  ip pim sparse-mode

    • Configure Loopback for Anycast RP 

      
interface loopback1
  ip address 100.1.1.1/32 tag 12345
  ip pim sparse-mode

    • Configure Anycast RP 

      

ip pim rp-address 100.1.1.1 group-list 224.0.0.0/4
ip pim anycast-rp 100.1.1.1 10.1.1.1
ip pim anycast-rp 100.1.1.1 20.1.1.1

    • Configure route-map used by EBGP for Spine 

      
route-map NEXT-HOP-UNCH permit 10
  set ip next-hop unchanged

    • Configure route-map to Redistribute Loopback

      route-map LOOPBACK permit 10
  match tag 12345

    • Configure interfaces for Spine-leaf interconnect 

      
interface Ethernet4/2
  ip address 192.168.1.42/24
  ip pim sparse-mode
  no shutdown

interface Ethernet4/3
  ip address 192.168.2.43/24
  ip pim sparse-mode
  no shutdown

    • Configure the BGP overlay for the EVPN address family. 

      
router bgp 100
  router-id 10.1.1.1
  address-family l2vpn evpn
    nexthop route-map NEXT-HOP-UNCH
    retain route-target all
  neighbor 30.1.1.1 remote-as 200
    update-source loopback0
    ebgp-multihop 3
    address-family l2vpn evpn
      send-community both
      disable-peer-as-check
      route-map NEXT-HOP-UNCH out
  neighbor 40.1.1.1 remote-as 200
    update-source loopback0
    ebgp-multihop 3
    address-family l2vpn evpn
      send-community both
      disable-peer-as-check
      route-map NEXT-HOP-UNCH out

    • Configure BGP underlay for the IPv4 unicast address family.

      
 address-family ipv4 unicast
    redistribute direct route-map LOOPBACK
  neighbor 192.168.1.22 remote-as 200
    update-source ethernet4/2
    address-family ipv4 unicast
      allowas-in
      disable-peer-as-check
  neighbor 192.168.2.23 remote-as 200
    update-source ethernet4/3
    address-family ipv4 unicast
      allowas-in
      disable-peer-as-check

  • Spine (9504-B)

    • Enable the EVPN control plane

      

nv overlay evpn

    • Enable the relevant protocols 

      

feature bgp
feature pim

    • Configure Loopback for local Router ID, PIM, and BGP

      interface loopback0
  ip address 20.1.1.1/32 tag 12345
  ip pim sparse-mode

    • Configure Loopback for AnycastRP

      interface loopback1
  ip address 100.1.1.1/32 tag 12345
  ip pim sparse-mode

    • Configure Anycast RP 

      

ip pim rp-address 100.1.1.1 group-list 224.0.0.0/4
ip pim anycast-rp 100.1.1.1 10.1.1.1
ip pim anycast-rp 100.1.1.1 20.1.1.1

    • Configure route-map used by EBGP for Spine 

      
route-map NEXT-HOP-UNCH permit 10
  set ip next-hop unchanged

    • Configure route-map to Redistribute Loopback

      route-map LOOPBACK permit 10
  match tag 12345

    • Configure interfaces for Spine-leaf interconnect 

      
interface Ethernet4/2
  no switchport
  ip address 192.168.3.42/24
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode
  no shutdown

interface Ethernet4/3
  no switchport
  ip address 192.168.4.43/24
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode
  shutdown

    • Configure BGP overlay for the EVPN address family 

      
router bgp 100
  router-id 20.1.1.1
  address-family l2vpn evpn
    nexthop route-map NEXT-HOP-UNCH
    retain route-target all
  neighbor 30.1.1.1 remote-as 200
    update-source loopback0
    ebgp-multihop 3
    address-family l2vpn evpn
      send-community both
      disable-peer-as-check
      route-map NEXT-HOP-UNCH out
  neighbor 40.1.1.1 remote-as 200
    update-source loopback0
    ebgp-multihop 3
    address-family l2vpn evpn
      send-community both
      disable-peer-as-check
      route-map NEXT-HOP-UNCH out

    • Configure the BGP underlay for the IPv4 unicast address family. 

      
  address-family ipv4 unicast
    redistribute direct route-map LOOPBACK
  neighbor 192.168.3.22 remote-as 200
    update-source ethernet4/2
    address-family ipv4 unicast
      allowas-in
      disable-peer-as-check
  neighbor 192.168.4.43 remote-as 200
    update-source ethernet4/3
    address-family ipv4 unicast
      allowas-in
      disable-peer-as-check

  • Leaf (9396-A)

    • Enable the EVPN control plane.

      nv overlay evpn

    • Enable the relevant protocols. 

      

feature bgp
feature pim
feature interface-vlan

    • Enable VXLAN with distributed anycast-gateway using BGP EVPN. 

      
feature vn-segment-vlan-based
feature nv overlay
fabric forwarding anycast-gateway-mac 0000.2222.3333

    • Enabling OSPF for underlay routing.

      router ospf 1

    • Configure Loopback for local Router ID, PIM, and BGP.

      interface loopback0
  ip address 30.1.1.1/32
  ip pim sparse-mode

    • Configure Loopback for VTEP.

      interface loopback1
  ip address 33.1.1.1/32
  ip pim sparse-mode

    • Configure interfaces for Spine-leaf interconnect.

      interface Ethernet2/2
  no switchport
  ip address 192.168.1.22/24
  ip pim sparse-mode
  no shutdown

interface Ethernet2/3
  no switchport
  ip address 192.168.4.23/24
  ip pim sparse-mode
  shutdown

    • Configure route-map to Redistribute Host-SVI (Silent Host).

      route-map HOST-SVI permit 10
  match tag 54321

    • Enable PIM RP. 

      

ip pim rp-address 100.1.1.1 group-list 224.0.0.0/4

    • Create VLANs.

      
vlan 1001-1002

    • Create overlay VRF VLAN and configure vn-segment.

      vlan 101
  vn-segment 900001

    • Configure core-facing SVI for VXLAN routing.

      interface vlan101
 no shutdown
  vrf member vxlan-900001
  ip forward
  no ip redirects
  ipv6 address use-link-local-only
  no ipv6 redirects

    • Create VLAN and provide mapping toVXLAN.

      vlan 1001
  vn-segment 2001001
vlan 1002
  vn-segment 2001002

    • Create VRF and configure VNI 

      
vrf context vxlan-900001
  vni 900001
  rd auto

      Note

      The rd auto and route-target commands are automatically configured unless one or more are entered as overrides. 

            
    address-family ipv4 unicast
      route-target both auto
      route-target both auto evpn
    address-family ipv6 unicast
      route-target both auto
      route-target both auto evpn

    • Create server facing SVI and enable distributed anycast-gateway 

      

interface vlan1001
  no shutdown
  vrf member vxlan-900001
  ip address 4.1.1.1/24 tag 54321
  ipv6 address 4:1:0:1::1/64 tag 54321
  fabric forwarding mode anycast-gateway

interface vlan1002
  no shutdown
  vrf member vxlan-900001
  ip address 4.2.2.1/24 tag 54321
  ipv6 address 4:2:0:1::1/64 tag 54321
  fabric forwarding mode anycast-gateway

    • Configure ACL TCAM region for ARP suppression


      Note

      The hardware access-list tcam region arp-ether 256 double-wide command is not needed for Cisco Nexus 9300-EX and 9300-FX/FX2 platform switches. 

      
hardware access-list tcam region arp-ether 256 double-wide

    • Note

      You can choose either of the following two options for creating the NVE interface. Use Option 1 for a small number of VNIs. Use Option 2 to leverage the simplified configuration mode.

      Create the network virtualization endpoint (NVE) interface

      Option 1

      


interface nve1
  no shutdown
  source-interface loopback1
  host-reachability protocol bgp
  member vni 900001 associate-vrf
  member vni 2001001
    mcast-group 239.0.0.1
  member vni 2001002
    mcast-group 239.0.0.1

      Option 2

      



interface nve1
  source-interface loopback1
  host-reachability protocol bgp
  global mcast-group 239.0.0.1 L2
  member vni 2001001
  member vni 2001002
  member vni 2001007-2001010

    • Configure interfaces for hosts/servers. 

      

interface Ethernet1/47
  switchport
  switchport access vlan 1002

interface Ethernet1/48
  switchport
  switchport access vlan 1001

    • Configure BGP underlay for the IPv4 unicast address family. 

      

router bgp 200
  router-id 30.1.1.1
  address-family ipv4 unicast
    redistribute direct route-map LOOPBACK
  neighbor 192.168.1.42 remote-as 100
    update-source ethernet2/2
    address-family ipv4 unicast
      allowas-in
      disable-peer-as-check
  neighbor 192.168.4.43 remote-as 100
    update-source ethernet2/3
    address-family ipv4 unicast
      allowas-in
      disable-peer-as-check

    • Configure BGP overlay for the EVPN address family.

        address-family l2vpn evpn
    nexthop route-map NEXT-HOP-UNCH
    retain route-target all
  neighbor 10.1.1.1 remote-as 100
    update-source loopback0
    ebgp-multihop 3
    address-family l2vpn evpn
      send-community both
      disable-peer-as-check
      route-map NEXT-HOP-UNCH out
  neighbor 20.1.1.1 remote-as 100
    update-source loopback0
    ebgp-multihop 3
    address-family l2vpn evpn
      send-community both
      disable-peer-as-check
      route-map NEXT-HOP-UNCH out
  vrf vxlan-900001

      Note

      The following commands in EVPN mode do not need to be entered. 

      evpn                                         
  vni 2001001 l2
  vni 2001002 l2

      Note

      The rd auto and route-target auto commands are automatically configured unless one or more are entered as overrides. 

      rd auto
route-target import auto
route-target export auto

      Note

      The following commands in EVPN mode do not need to be entered.

      evpn
  vni 2001001 l2
    rd auto
    route-target import auto
    route-target export auto
  vni 2001002 l2
    rd auto
    route-target import auto
    route-target export auto

  • Leaf (9396-B)

    • Enable the EVPN control plane. 

      

nv overlay evpn

    • Enable the relevant protocols. 

      

feature bgp
feature pim
feature interface-vlan

    • Enable VXLAN with distributed anycast-gateway using BGP EVPN.

      feature vn-segment-vlan-based
feature nv overlay
fabric forwarding anycast-gateway-mac 0000.2222.3333

    • Enabling OSPF for underlay routing.

      router ospf 1

    • Configure Loopback for local Router ID, PIM, and BGP.

      interface loopback0
  ip address 40.1.1.1/32
  ip pim sparse-mode

    • Configure Loopback for VTEP.

      interface loopback1
  ip address 44.1.1.1/32
  ip pim sparse-mode

    • Configure interfaces for Spine-leaf interconnect.

      interface Ethernet2/2
  no switchport
  ip address 192.168.3.22/24
  ip pim sparse-mode
  no shutdown

interface Ethernet2/3
  no switchport
  ip address 192.168.2.23/24
  ip pim sparse-mode
  shutdown

    • Configure route-map to Redistribute Host-SVI (Silent Host).

      route-map HOST-SVI permit 10
  match tag 54321

    • Enable PIM RP 

      

ip pim rp-address 100.1.1.1 group-list 224.0.0.0/4

    • Create VLANs

      
vlan 1001-1002

    • Create overlay VRF VLAN and configure vn-segment.

      
vlan 101
  vn-segment 900001

    • Configure core-facing SVI for VXLAN routing.

      interface vlan101
 no shutdown
  vrf member vxlan-900001
  ip forward
  no ip redirects
  ipv6 address use-link-local-only
  no ipv6 redirects

    • Create VLAN and provide mapping to VXLAN. 

      
vlan 1001
  vn-segment 2001001
vlan 1002
  vn-segment 2001002

    • Create VRF and configure VNI 

      
vrf context vxlan-900001
  vni 900001
  rd auto

      Note

      The following commands are automatically configured unless one or more are entered as overrides.

      		 
      
    address-family ipv4 unicast
      route-target both auto
      route-target both auto evpn
    address-family ipv6 unicast
      route-target both auto
      route-target both auto evpn

    • Create server facing SVI and enable distributed anycast-gateway.

      interface vlan1001
  no shutdown
  vrf member vxlan-900001
  ip address 4.1.1.1/24 tag 54321
  ipv6 address 4:1:0:1::1/64 tag 54321
  fabric forwarding mode anycast-gateway

interface vlan1002
  no shutdown
  vrf member vxlan-900001
  ip address 4.2.2.1/24 tag 54321
  ipv6 address 4:2:0:1::1/64 tag 54321
  fabric forwarding mode anycast-gateway

    • Configure ACL TCAM region for ARP suppression


      Note

      The hardware access-list tcam region arp-ether 256 double-wide command is not needed for Cisco Nexus 9300-EX and 9300-FX/FX2 platform switches. 

      

hardware access-list tcam region arp-ether 256 double-wide

    • Note

      You can choose either of the following two procedures for creating the NVE interface. Use Option 1 for a small number of VNIs. Use Option 2 to leverage the simplified configuration mode.

      Create the network virtualization endpoint (NVE) interface.

      Option 1

      


interface nve1
  no shutdown
  source-interface loopback1
  host-reachability protocol bgp
  member vni 900001 associate-vrf
  member vni 2001001
    mcast-group 239.0.0.1
  member vni 2001002
    mcast-group 239.0.0.1

      Option 2

      


interface nve1
  source-interface loopback1
  host-reachability protocol bgp
  global mcast-group 239.0.0.1 L2
  member vni 2001001
  member vni 2001002
  member vni 2001007-2001010

    • Configure interfaces for hosts/servers 

      

interface Ethernet1/47
  switchport
  switchport access vlan 1002

interface Ethernet1/48
  switchport
  switchport access vlan 1001

    • Configure BGP underlay for the IPv4 unicast address family.

      router bgp 200
  router-id 40.1.1.1
  address-family ipv4 unicast
    redistribute direct route-map LOOPBACK
  neighbor 192.168.3.42 remote-as 100
    update-source ethernet2/2
    address-family ipv4 unicast
      allowas-in
      disable-peer-as-check
  neighbor 192.168.2.43 remote-as 100
    update-source ethernet2/3
    address-family ipv4 unicast
      allowas-in
      disable-peer-as-check

    • Configure BGP overlay for the EVPN address family.

        address-family l2vpn evpn
    nexthop route-map NEXT-HOP-UNCH
    retain route-target all
  neighbor 10.1.1.1 remote-as 100
    update-source loopback0
    ebgp-multihop 3
    address-family l2vpn evpn
      send-community both
      disable-peer-as-check
      route-map NEXT-HOP-UNCH out
  neighbor 20.1.1.1 remote-as 100
    update-source loopback0
    ebgp-multihop 3
    address-family l2vpn evpn
      send-community both
      disable-peer-as-check
      route-map NEXT-HOP-UNCH out
  vrf vxlan-900001

    Note

    The following commands in EVPN mode do not need to be entered. 

    evpn                                         
  vni 2001001 l2
  vni 2001002 l2

    Note

    The rd auto and route-target auto commands are automatically configured unless one or more are entered as overrides. 

    rd auto
route-target import auto
route-target export auto

    Note

    The following commands in EVPN mode do not need to be entered.

    evpn
  vni 2001001 l2
    rd auto
    route-target import auto
    route-target export auto
  vni 2001002 l2
    rd auto
    route-target import auto
    route-target export auto

Example Show Commands

  • show nve peers 

    
9396-B# show nve peers
Interface Peer-IP          State LearnType Uptime   Router-Mac      
--------- ---------------  ----- --------- -------- -----------------
nve1      30.1.1.1         Up    CP        00:00:38 6412.2574.9f27

  • show nve vni 

    
9396-B# show nve vni
Codes: CP - Control Plane        DP - Data Plane         
       UC - Unconfigured         
      
Interface VNI      Multicast-group   State Mode Type [BD/VRF]      Flags
--------- -------- ----------------- ----- ---- ------------------ -----
nve1      900001   n/a               Up    CP   L3 [vxlan-900001]      
nve1      2001001  225.4.0.1         Up    CP   L2 [1001]            
nve1      2001002  225.4.0.1         Up    CP   L2 [1002]

  • show ip arp suppression-cache detail 

    
9396-B# show ip arp suppression-cache detail
 
Flags: + - Adjacencies synced via CFSoE
       L - Local Adjacency
       R - Remote Adjacency
       L2 - Learnt over L2 interface
 
Ip Address      Age      Mac Address    Vlan Physical-ifindex    Flags
 
4.1.1.54        00:06:41 0054.0000.0000 1001 Ethernet1/48        L
4.1.1.51        00:20:33 0051.0000.0000 1001 (null)              R
4.2.2.53        00:06:41 0053.0000.0000 1002 Ethernet1/47        L
4.2.2.52        00:20:33 0052.0000.0000 1002 (null)              R

  • Note

    The show vxlan interface command is not supported for the Cisco Nexus 9300-EX, 9300-FX/FX2 platform switches.

  • show vxlan interface 

    
9396-B# show vxlan interface
Interface       Vlan    VPL Ifindex     LTL             HW VP
=========       ====    ===========     ===             =====
Eth1/47         1002    0x4c07d22e      0x10000         5697
Eth1/48         1001    0x4c07d02f      0x10001         5698

  • show bgp l2vpn evpn summary 

    
leaf3# show bgp l2vpn evpn summary
BGP summary information for VRF default, address family L2VPN EVPN
BGP router identifier 40.0.0.4, local AS number 10
BGP table version is 60, L2VPN EVPN config peers 1, capable peers 1
21 network entries and 21 paths using 2088 bytes of memory
BGP attribute entries [8/1152], BGP AS path entries [0/0]
BGP community entries [0/0], BGP clusterlist entries [1/4]

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down
State/PfxRcd    
40.0.0.1        4    10    8570    8565       60    0    0    5d22h 6
leaf3#

  • show bgp l2vpn evpn 

    
leaf3# show bgp l2vpn evpn
BGP routing table information for VRF default, address family L2VPN EVPN
BGP table version is 60, local router ID is 40.0.0.4
Status: s-suppressed, x-deleted, S-stale, d-dampened, h-history, *-valid,
>-best
Path type: i-internal, e-external, c-confed, l-local, a-aggregate, r-redist,
I-injected
Origin codes: i - IGP, e - EGP, ? - incomplete, | - multipath, & - backup

   Network            Next Hop            Metric     LocPrf     Weight Path
Route Distinguisher: 40.0.0.2:32868
*>i[2]:[0]:[10001]:[48]:[0000.8816.b645]:[0]:[0.0.0.0]/216
                      40.0.0.2                          100          0 i
*>i[2]:[0]:[10001]:[48]:[0011.0000.0034]:[0]:[0.0.0.0]/216
                      40.0.0.2                          100          0 i

  • show l2route evpn mac all 

    
leaf3# show l2route evpn mac all
Topology    Mac Address    Prod   Next Hop (s)
----------- -------------- ------ ---------------
101         0000.8816.b645 BGP    40.0.0.2
101         0001.0000.0033 Local  Ifindex 4362086
101         0001.0000.0035 Local  Ifindex 4362086
101         0011.0000.0034 BGP    40.0.0.2

  • show l2route evpn mac-ip all 

    
leaf3# show l2route evpn mac-ip all
Topology ID Mac Address    Prod Host IP                 Next Hop (s)
----------- -------------- ---- ------------------------------------------------------
101         0011.0000.0034 BGP  5.1.3.2                      40.0.0.2
102         0011.0000.0034 BGP  5.1.3.2                      40.0.0.2