Contents

Introduction

Prerequisites

Requirements

Components Used

Background Information

Underlay and Overlay Configuration for VxLAN in Laboratory

SPINE

LEAF-1

LEAF-1-vPC

LEAF-2-vPC

N9K-ACCESS

DHCP Configuration on Nexus switches

LEAF-1

LEAF-1-vPC DHCP

LEAF-2-vPC DHCP

DHCP server configuration on Windows Server 2022

IP addressing scope configuration for hosts.

Configuring scope for unique IP addresses from loopbacks in SVI as DCHP relay agent.

Configuring superscope for VxLAN fabric.

Configure Option 82 in host scopes.

DCHP packet-walk from beginning to end in VxLAN Fabric.

Discovery send by HOST-1

Discovery on LEAF-1

Discovery on SPINE

Discovery on LEAF-1-vPC

Disccovery received on DCHP Server

DCHP Offer send by DCHP Server

DCHP Offer on LEAF-2-vPC

DHCP Offer vPC SPINE

DHCP Offer on LEAF-1

DHCP Offer received on HOST-1

Request send by HOST-1

Request on LEAF-1

Request on SPINE

Request on LEAF-2-vPC

Request received on DCHP Server

ACK send by DCHP Server

ACK on LEAF-2-vPC

ACK on SPINE

ACK on LEAF-1

ACK on HOST-1

Related information

Introduction

This document describes how to configure and troubleshoot DHCP in a VxLAN Fabric with Nexus 9000 switches.

Prerequisites

Requirements

Cisco recommends that you have knowledge of these topics:

- Nexus NX-OS Software.

- Virtual Port Channel (vPC).

- VxLAN BGP L2VPN EVPN

- BGP address-family IPv4

- OSPF

- Multicast PIM (sparse-mode)

- DHCP

Components Used

The information in this document is based on these software and hardware versions:

- Cisco Nexus 9000 with Cisco NX-OS.

- N9K-C93180YC-EX

- N9K-C93180YC-FX

- NX-OS 10.3(4a)

- Windows Server 2022 Data Center

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, ensure that you understand the potential impact of any command.

Note: Any questions about the configuration and integrability of third-party software or hardware are outside of Cisco support. The use of third-party tools is a best effort to demonstrate your configuration and operation with Cisco equipment to customer.

Background Information

Underlay and Overlay Configuration for VxLAN in Laboratory

VxLAN Fabric Diagram in Laboratory

- SPINE:

- This Nexus switch sends DHCP (Discover, Offer, Request, Ack) packets without being decapsulated in this scenario. Only the outer header is used.

- Acts as the central routing points in the network fabric.

- Responsible for interconnecting all the LEAF switches and facilitating the flow of data between them.

- Participates in BGP to distribute EVPN routes to the LEAF switches.

- Performs IP routing and can route traffic between different subnets or VxLAN segments by looking at the outer IP headers.

- Separates the overlay network (VxLAN) from the underlay physical network.

- Manages the underlay with traditional IP routing protocols, while the overlay is managed by VxLAN with BGP EVPN, providing a scalable and flexible network architecture.

- LEAF-1:

- LEAF switches provide physical connectivity for endpoints like servers, storage devices, and other network appliances.

- LEAF switches act as VTEPs, which means they encapsulate and de-encapsulate the VxLAN packets.

- In this scenario HOST#1 makes the IP address request.

- LEAF-1 is responsible for encapsulating the DCHP packets within VxLAN header.

- HOST#1 receives DCHP packets transparently as classic Ethernet.

- LEAF-1-vPC and LEAF-2-vPC:

- LEAF switches participate in the EVPN control plane by running BGP and exchanging route information. This allows for the distribution of MAC and IP address information, ensuring that traffic can be efficiently routed across the VxLAN fabric.

- In this scenario, the DHCP server is associated with VLAN 10 with VNI 101010 as is HOST#1. This means it is only VxLAN bridging.

- If the DHCP Server was associated with a VNI other than HOST#1, then an L3VNI would be strictly necessary for routing. The source and destination VNI must be created.

- DCHP server receives DCHP packets transparently as classic Ethernet.

- The BUM traffic is received by both Nexus switches in vPC, but only the operationally primary Nexus switch in vPC sends the traffic. The secondary Nexus switch drop the traffic. In this scenario LEAF-1-vPC is operationally primary.

- The use of infra-vlans is mandatory because if the interface on LEAF-2-vPC to SPINE goes down, DCHP packets could not be sent. To send VxLAN-encapsulated traffic to LEAF-1-vPC, this backup VLAN is required. In this way LEAF-1-vPC could send DCHP packets to SPINE.

- N9K-ACCESS:

- This Nexus switch only provides connectivity to both Leafs using a vPC port-channel for redundancy purposes towards HOST#2

SPINE

nv overlay evpn

feature ospf

feature bgp

feature pim

feature netconf

feature nv overlay

ip pim rp-address 192.168.11.11 group-list 224.10.10.0/24

ip pim ssm range 232.0.0.0/8

ip pim anycast-rp 192.168.11.11 192.168.0.11

ip prefix-list direct_routes seq 5 permit 10.104.11.0/30 le 32

route-map redistribution permit 10

match ip address prefix-list direct_routes

interface Ethernet1/1

speed 1000

ip address 10.104.11.1/30

ip ospf network point-to-point

ip router ospf 1 area 0.0.0.0

ip pim sparse-mode

no shutdown

interface Ethernet1/2

ip address 10.102.11.1/30

ip ospf network point-to-point

ip router ospf 1 area 0.0.0.0

ip pim sparse-mode

no shutdown

interface Ethernet1/3

speed 1000

ip address 10.103.11.1/30

ip ospf network point-to-point

ip router ospf 1 area 0.0.0.0

ip pim sparse-mode

no shutdown

interface loopback0

description ANYCAST-RP

ip address 192.168.0.11/32

ip router ospf 1 area 0.0.0.0

ip pim sparse-mode

interface loopback1

description ANYCAST-RP-CANDIDATE

ip address 192.168.11.11/32

ip router ospf 1 area 0.0.0.0

ip pim sparse-mode

router ospf 1

router bgp 65000

neighbor 192.168.3.3

remote-as 65000

update-source loopback0

address-family l2vpn evpn

send-community

send-community extended

route-reflector-client

neighbor 192.168.4.4

remote-as 65000

update-source loopback0

address-family l2vpn evpn

send-community

send-community extended

route-reflector-client

neighbor 192.168.5.5

remote-as 65000

update-source loopback0

address-family l2vpn evpn

send-community

send-community extended

route-reflector-client

LEAF-1

nv overlay evpn

feature ospf

feature bgp

feature pim

feature interface-vlan

feature vn-segment-vlan-based

feature dhcp

feature nv overlay

fabric forwarding anycast-gateway-mac 0000.0a0a.0a0a

ip pim rp-address 192.168.11.11 group-list 224.10.10.0/24

ip pim ssm range 232.0.0.0/8

vlan 1,10,20,300

vlan 10

vn-segment 101010

vlan 20

vn-segment 202020

vlan 300

vn-segment 303030

spanning-tree vlan 10 priority 4096

ip prefix-list host_subnets seq 5 permit 10.10.10.0/24 le 32

ip prefix-list host_subnets seq 10 permit 192.168.20.0/24 le 32

ip prefix-list host_subnets seq 15 permit 172.16.10.8/32

route-map direct_routes_tenant-a permit 10

match ip address prefix-list host_subnets

vrf context tenant-a

vni 303030

rd auto

address-family ipv4 unicast

route-target both auto

route-target both auto evpn

interface Vlan10

no shutdown

vrf member tenant-a

no ip redirects

ip address 10.10.10.1/24

no ipv6 redirects

fabric forwarding mode anycast-gateway

ip dhcp relay address 10.10.10.150

ip dhcp relay source-interface loopback100

interface Vlan20

no shutdown

vrf member tenant-a

no ip redirects

ip address 192.168.20.1/24

no ipv6 redirects

fabric forwarding mode anycast-gateway

interface Vlan300

no shutdown

vrf member tenant-a

no ip redirects

ip forward

no ipv6 redirects

interface nve1

no shutdown

host-reachability protocol bgp

source-interface loopback0

member vni 101010

suppress-arp

mcast-group 224.10.10.10

member vni 202020

suppress-arp

mcast-group 224.10.10.10

member vni 303030 associate-vrf

interface Ethernet1/1

ip address 10.104.11.2/30

ip ospf network point-to-point

ip router ospf 1 area 0.0.0.0

ip pim sparse-mode

no shutdown

interface loopback0

description UNDERLAY-VERIFICATION

ip address 192.168.5.5/32

ip router ospf 1 area 0.0.0.0

ip pim sparse-mode

interface loopback100

vrf member tenant-a

ip address 172.16.10.8/32

router ospf 1

router bgp 65000

address-family ipv4 unicast

neighbor 192.168.0.11

remote-as 65000

update-source loopback0

address-family l2vpn evpn

send-community

send-community extended

vrf tenant-a

address-family ipv4 unicast

redistribute direct route-map direct_routes_tenant-a

evpn

vni 101010 l2

rd auto

route-target import auto

route-target export auto

vni 202020 l2

rd auto

route-target import auto

route-target export auto

LEAF-1-vPC

nv overlay evpn

feature ospf

feature bgp

feature pim

feature interface-vlan

feature vn-segment-vlan-based

feature lacp

feature dhcp

feature vpc

feature nv overlay

fabric forwarding anycast-gateway-mac 0000.0a0a.0a0a

ip pim rp-address 192.168.11.11 group-list 224.10.10.0/24

ip pim ssm range 232.0.0.0/8

vlan 1,10,300,777

vlan 10

vn-segment 101010

vlan 300

vn-segment 303030

vlan 777

name BACKUP_VLAN_ROUTING_NVE_INFRA

spanning-tree vlan 1,10,300 hello-time 4

ip prefix-list host_subnets seq 5 permit 10.10.10.0/24 le 32

ip prefix-list host_subnets seq 15 permit 172.16.10.9/32

route-map direct_routes_tenant-a permit 10

match ip address prefix-list host_subnets

vrf context tenant-a

vni 303030

rd auto

address-family ipv4 unicast

route-target both auto

route-target both auto evpn

system nve infra-vlans 777

vpc domain 1

peer-switch

peer-keepalive destination 10.88.238.195

peer-gateway

layer3 peer-router

ip arp synchronize

interface Ethernet1/3

switchport

switchport mode trunk

switchport trunk allowed vlan 1,10,20

channel-group 10 mode active

no shutdown

interface Ethernet1/19

switchport

switchport mode trunk

channel-group 1 mode active

no shutdown

interface port-channel1

switchport

switchport mode trunk

spanning-tree port type network

vpc peer-link

interface port-channel10

switchport

switchport mode trunk

switchport trunk allowed vlan 1,10

vpc 10

interface mgmt0

vrf member management

ip address 10.88.238.194/29

interface loopback0

description UNDERLAY-VERIFICATION

ip address 192.168.3.3/32

ip router ospf 1 area 0.0.0.0

ip pim sparse-mode

interface loopback1

description OVERLAY-NVE

ip address 192.168.13.1/32

ip address 192.168.13.254/32 secondary

ip router ospf 1 area 0.0.0.0

ip pim sparse-mode

interface loopback10

vrf member tenant-a

ip address 172.16.10.1/32

interface loopback100

vrf member tenant-a

ip address 172.16.10.9/32

interface Vlan10

no shutdown

vrf member tenant-a

no ip redirects

ip address 10.10.10.1/24

no ipv6 redirects

fabric forwarding mode anycast-gateway

ip dhcp relay address 10.10.10.150

ip dhcp relay source-interface loopback100

interface Vlan300

no shutdown

vrf member tenant-a

no ip redirects

ip forward

no ipv6 redirects

interface Vlan777

description BACKUP_UNDERLAY_INFRA-VLAN

no shutdown

no ip redirects

ip address 10.255.77.1/30

no ipv6 redirects

ip ospf network point-to-point

ip router ospf 1 area 0.0.0.0

ip pim sparse-mode

interface Ethernet1/2

ip address 10.102.11.2/30

ip ospf network point-to-point

ip router ospf 1 area 0.0.0.0

ip pim sparse-mode

no shutdown

interface nve1

no shutdown

host-reachability protocol bgp

advertise virtual-rmac

source-interface loopback1

member vni 101010

suppress-arp

mcast-group 224.10.10.10

member vni 303030 associate-vrf

router ospf 1

router bgp 65000

address-family ipv4 unicast

address-family l2vpn evpn

advertise-pip

neighbor 192.168.0.11

remote-as 65000

update-source loopback0

address-family l2vpn evpn

send-community

send-community extended

neighbor 192.168.88.2

remote-as 65000

description OVERLAY_BACKUP

update-source Vlan888

address-family l2vpn evpn

send-community

send-community extended

vrf tenant-a

address-family ipv4 unicast

redistribute direct route-map direct_routes_tenant-a

evpn

vni 101010 l2

rd auto

route-target import auto

route-target export auto

vni 202020 l2

rd auto

route-target import auto

route-target export auto

LEAF-2-vPC

nv overlay evpn

feature ospf

feature bgp

feature pim

feature interface-vlan

feature vn-segment-vlan-based

feature lacp

feature dhcp

feature vpc

feature nv overlay

fabric forwarding anycast-gateway-mac 0000.0a0a.0a0a

ip pim rp-address 192.168.11.11 group-list 224.10.10.0/24

ip pim ssm range 232.0.0.0/8

vlan 1,10,20,300,777

vlan 10

vn-segment 101010

vlan 20

vn-segment 202020

vlan 300

vn-segment 303030

vlan 777

name BACKUP_VLAN_ROUTING_NVE_INFRA

spanning-tree vlan 1,10,20,300 hello-time 4

ip prefix-list host_subnets seq 5 permit 10.10.10.0/24 le 32

ip prefix-list host_subnets seq 10 permit 192.168.20.0/24 le 32

ip prefix-list host_subnets seq 15 permit 172.16.10.10/32

route-map direct_routes_tenant-a permit 10

match ip address prefix-list host_subnets

vrf context tenant-a

vni 303030

rd auto

address-family ipv4 unicast

route-target both auto

route-target both auto evpn

system nve infra-vlans 777

vpc domain 1

peer-switch

peer-keepalive destination 10.88.238.194

peer-gateway

layer3 peer-router

ip arp synchronize

interface Ethernet1/1

ip address 10.103.11.2/30

ip ospf network point-to-point

ip router ospf 1 area 0.0.0.0

ip pim sparse-mode

no shutdown

interface Ethernet1/19

switchport

switchport mode trunk

channel-group 1 mode active

no shutdown

interface port-channel1

switchport

switchport mode trunk

spanning-tree port type network

vpc peer-link

interface port-channel10

switchport

switchport mode trunk

switchport trunk allowed vlan 1,10,20

vpc 10

interface mgmt0

vrf member management

ip address 10.88.238.195/29

interface loopback0

description UNDERLAY-VERIFICATION

ip address 192.168.4.4/32

ip router ospf 1 area 0.0.0.0

ip pim sparse-mode

interface loopback1

description OVERLAY-NVE

ip address 192.168.13.2/32

ip address 192.168.13.254/32 secondary

ip router ospf 1 area 0.0.0.0

ip pim sparse-mode

interface loopback10

vrf member tenant-a

ip address 172.16.10.2/32

interface loopback100

vrf member tenant-a

ip address 172.16.10.10/32

interface Vlan10

no shutdown

vrf member tenant-a

no ip redirects

ip address 10.10.10.1/24

no ipv6 redirects

fabric forwarding mode anycast-gateway

ip dhcp relay address 10.10.10.150

ip dhcp relay source-interface loopback100

interface Vlan20

no shutdown

vrf member tenant-a

no ip redirects

ip address 192.168.20.1/24

no ipv6 redirects

fabric forwarding mode anycast-gateway

interface Vlan300

no shutdown

vrf member tenant-a

no ip redirects

ip forward

no ipv6 redirects

interface Vlan777

description BACKUP_UNDERLAY_INFRA-VLAN

no shutdown

no ip redirects

ip address 10.255.77.2/30

no ipv6 redirects

ip ospf network point-to-point

ip router ospf 1 area 0.0.0.0

ip pim sparse-mode

interface nve1

no shutdown

host-reachability protocol bgp

advertise virtual-rmac

source-interface loopback1

member vni 101010

suppress-arp

mcast-group 224.10.10.10

member vni 202020

suppress-arp

mcast-group 224.10.10.10

member vni 303030 associate-vrf

router ospf 1

router bgp 65000

address-family ipv4 unicast

address-family l2vpn evpn

advertise-pip

neighbor 192.168.0.11

remote-as 65000

update-source loopback0

address-family l2vpn evpn

send-community

send-community extended

neighbor 192.168.88.1

remote-as 65000

description OVERLAY_BACKUP

update-source Vlan888

address-family l2vpn evpn

send-community

send-community extended

vrf tenant-a

address-family ipv4 unicast

redistribute direct route-map direct_routes_tenant-a

evpn

vni 101010 l2

rd auto

route-target import auto

route-target export auto

vni 202020 l2

rd auto

route-target import auto

route-target export auto

N9K-ACCESS

feature lacp

vlan 1,10

interface port-channel10

switchport

switchport mode trunk

interface Ethernet1/11

switchport

switchport access vlan 10

no shutdown

interface Ethernet1/45

switchport

switchport mode trunk

channel-group 10 mode active

no shutdown

interface Ethernet1/46

switchport

switchport mode trunk

channel-group 10 mode active

no shutdown

DHCP Configuration on Nexus switches

LEAF-1

Step 1. Enable the feature DCHP.

LEAF-1(config)# feature dhcp

Note: The DHCP server and the relay agent command service dhcp, ip dhcp relay, and ipv6 dhcp relay are enabled by default since NX-OS 7.x.

Step 2. Apply the command ip dhcp relay information option.

LEAF-1(config)# ip dhcp relay information option

Note: This command enables the DHCP relay agent to insert and remove Option 82 information on the packets that are forwarded.

Step 3. Apply the command ip dhcp relay information option vpn.

LEAF-1(config)# ip dhcp relay information option vpn

Note: This command enables the DHCP relay requests that arrives on different VRF where the DHCP server belongs.

Step 4. Apply the command "ip dhcp relay address [ip address of DCHP server]".

Note: In this example the IP address for DCHP server is 10.10.10.150.

LEAF-1(config)# interface vlan 10

LEAF-1(config-if)# ip dhcp relay address 10.10.10.150

Step 5. Apply the command "ip dhcp relay source-interface [unique loopback]".

Note: This command configures the source IP address for DHCP relay agent to handle Discover, Offer, Request, and ACK, for unicast communication which the DHCP relay agent uses the IP address of SVI as source IP address for DHCP relay agent. This is not desired because this IP address is shared by multiples VTEPs and black-holing of DHCP packets can happen. To avoid this, a unique IP address (using a loopback interface) is necessary to differentiate each VTEP.

LEAF-1(config)# interface vlan 10

LEAF-1(config-if)# ip dhcp relay source-interface loopback100

Step 6. In the VRF corresponding tenant within BGP, direct route redistribution with a prefix-list and route-map that includes the IP address of the loopback interface.

Note: This loopback interface belongs to the tenant of SVI.

LEAF-1(config)# show running-config interface loopback 100

interface loopback100

vrf member tenant-a

ip address 172.16.10.8/32

LEAF-1(config)# ip prefix-list host_subnets seq 15 permit 172.16.10.8/32

LEAF-1(config)# route-map direct_routes_tenant-a permit 10

LEAF-1(config-route-map)# match ip address prefix-list host_subnets

LEAF-1(config-route-map)# router bgp 65000

LEAF-1(config-router)# vrf tenant-a

LEAF-1(config-router-vrf)# address-family ipv4 unicast

LEAF-1(config-router-vrf-af)# redistribute direct route-map direct_routes_tenant-a

Step 7. Verify that the IP address of the loopback interface is advertised in BGP L2VPN EVPN to the Spines with the command: show bgp l2vpn evpn [loopback IP] vrf [tenant vrf].

LEAF-1(config)# show bgp l2vpn evpn 172.16.10.8 vrf tenant-a

BGP routing table information for VRF default, address family L2VPN EVPN

Route Distinguisher: 192.168.5.5:4    (L3VNI 303030)

BGP routing table entry for [5]:[0]:[0]:[32]:[172.16.10.8]/224, version 421

Paths: (1 available, best #1)

Flags: (0x000002) (high32 00000000) on xmit-list, is not in l2rib/evpn

Advertised path-id 1

Path type: local, path is valid, is best path, no labeled nexthop

Gateway IP: 0.0.0.0

AS-Path: NONE, path locally originated

192.168.5.5 (metric 0) from 0.0.0.0 (192.168.5.5)

Origin incomplete, MED 0, localpref 100, weight 32768

Received label 303030

Extcommunity: RT:65000:303030 ENCAP:8 Router MAC:707d.b9b8.4daf

Path-id 1 advertised to peers:

192.168.0.11 <<<< Spine

Step 8. Verify that the IP address of the loopback interface is injected in BGP L2VPN EVPN where DHCP server is located.

Note: If there are Nexus switches in vPC, verify that they both learn the IP address of the loopback interface in BGP L2VPN EVPN.

LEAF-1# show bgp l2vpn evpn 172.16.10.8

BGP routing table information for VRF default, address family L2VPN EVPN

Route Distinguisher: 192.168.5.5:4

BGP routing table entry for [5]:[0]:[0]:[32]:[172.16.10.8]/224, version 754

Paths: (1 available, best #1)

Flags: (0x000002) (high32 00000000) on xmit-list, is not in l2rib/evpn, is not in HW

Advertised path-id 1

Path type: internal, path is valid, is best path, no labeled nexthop

Imported to 2 destination(s)

Imported paths list: tenant-a L3-303030

Gateway IP: 0.0.0.0

AS-Path: NONE, path sourced internal to AS

192.168.5.5 (metric 45) from 192.168.0.11 (192.168.0.11)

Origin incomplete, MED 0, localpref 100, weight 0

Received label 303030

Extcommunity: RT:65000:303030 ENCAP:8 Router MAC:707d.b9b8.4daf

Originator: 192.168.5.5 Cluster list: 192.168.0.11

Path-id 1 not advertised to any peer

Route Distinguisher: 192.168.3.3:4    (L3VNI 303030)

BGP routing table entry for [5]:[0]:[0]:[32]:[172.16.10.8]/224, version 761

Paths: (1 available, best #1)

Flags: (0x000002) (high32 00000000) on xmit-list, is not in l2rib/evpn, is not in HW

Advertised path-id 1

Path type: internal, path is valid, is best path, no labeled nexthop

Imported from 192.168.5.5:4:[5]:[0]:[0]:[32]:[172.16.10.8]/224

Gateway IP: 0.0.0.0

AS-Path: NONE, path sourced internal to AS

192.168.5.5 (metric 45) from 192.168.0.11 (192.168.0.11)

Origin incomplete, MED 0, localpref 100, weight 0

Received label 303030

Extcommunity: RT:65000:303030 ENCAP:8 Router MAC:707d.b9b8.4daf

Originator: 192.168.5.5 Cluster list: 192.168.0.11

Path-id 1 not advertised to any peer

Step 9. Verify that there is a route for the DHCP server on the source tenant with command show ip route [DHCP server IP] vrf [tenant vrf].

Note: The route entry to use must be from VxLAN to default VRF. If there is no route available, check if the VTEP locally knows the DCHP server IP address.

LEAF-1# show running-config interface vlan 10

interface Vlan10

no shutdown

vrf member tenant-a <<<< source tenant

no ip redirects

ip address 10.10.10.1/24

no ipv6 redirects

fabric forwarding mode anycast-gateway

ip dhcp relay address 10.10.10.150 <<<< DHCP server

ip dhcp relay source-interface loopback100

LEAF-1# show ip route 10.10.10.150 vrf tenant-a

10.10.10.150/32, ubest/mbest: 1/0

*via 192.168.13.254%default, [200/0], 2w0d, bgp-65000, internal, tag 65000, segid: 303030 tunnelid: 0xd0d0dfe encap: VXLAN

Step 10. Verify that the DCHP server IP is reachable using the loopback interface and the corresponding VRF as a VRF source with command ping [DHCP server IP] source-interface loopback [x] vrf [tenant vrf].

LEAF-1# ping 10.10.10.150 source-interface loopback 100 vrf tenant-a

PING 10.10.10.150 (10.10.10.150): 56 data bytes

64 bytes from 10.10.10.150: icmp_seq=0 ttl=126 time=1.262 ms

64 bytes from 10.10.10.150: icmp_seq=1 ttl=126 time=0.833 ms

64 bytes from 10.10.10.150: icmp_seq=2 ttl=126 time=0.808 ms

64 bytes from 10.10.10.150: icmp_seq=3 ttl=126 time=0.795 ms

64 bytes from 10.10.10.150: icmp_seq=4 ttl=126 time=0.78 ms

--- 10.10.10.150 ping statistics ---

5 packets transmitted, 5 packets received, 0.00% packet loss

Step 11. Verify the status of the DHCP relay agent.

LEAF-1# show ip dhcp status

Current CLI Operation: show ip dhcp status

Last CLI Operation: DME: ip dhcp relay information option enable

Last CLI Operation Status: SUCCESS

Step 12. Verify the option82, such as vpn option and the correct relay IP address under the relay agent.

LEAF-1# show ip dhcp relay

DHCP relay service is enabled   <<<<<<

Insertion of option 82 is enabled  <<<<<<

Insertion of option 82 customize circuitid is disabled

TLV format in CircuitId and RemoteId suboptions is enabled

Insertion of VPN suboptions is enabled  <<<<<<<

Insertion of cisco suboptions is disabled

Global smart-relay is disabled

Relay Trusted functionality is disabled

Relay Trusted Port is Globally disabled

V4 Relay Source Address HSRP is Globally disabled

Server-ID-override-disable is disabled

Smart-relay is enabled on the following interfaces:

------------------------------------------------------

Subnet-broadcast is enabled on the following interfaces:

------------------------------------------------------

Relay Trusted Port is enabled on the following interfaces:

----------------------------------------------------------

Relay Source Address HSRP is enabled on the following interfaces:

-------------------------------------------------------------------

Helper addresses are configured on the following interfaces:

Interface        Relay Address     VRF Name

-------------    -------------     --------

Vlan10            10.10.10.150   <<<<<<<<<

Step 13. Verify the statistics of packets processed and forwarded.

LEAF-1# show ip dhcp global statistics

Packets processed 1297177

Packets received through cfsoe 0

Packets forwarded 1297175

Packets forwarded on cfsoe 0

Total packets dropped 0

Packets dropped from untrusted ports 0

Packets dropped due to MAC address check failure 0

Packets dropped due to Option 82 insertion failure 0

Packets dropped due to o/p intf unknown 0

Packets dropped which were unknown 0

Packets dropped due to no trusted ports 0

Packets dropped due to dhcp relay not enabled 0

Packets dropped due to no binding entry 0

Packets dropped due to interface error/no interface 0

Packets dropped due to max hops exceeded 0

Packets dropped due to Queue full 0

Step 14. Verify the statistics of relay packets.

LEAF-1# show ip dhcp relay statistics

----------------------------------------------------------------------

Message Type             Rx              Tx           Drops

----------------------------------------------------------------------

Discover             260521          260520               0

Offer                289330          289330               0

Request(*)           267162          267161               0

Ack                    8322            8322               0

Release(*)           181121          181121               0

Decline                   1               1               0

Inform(*)                 0               0               0

Nack                 289280          289280               0

----------------------------------------------------------------------

Total               1295737         1295735               0

----------------------------------------------------------------------

DHCP L3 FWD:

Total Packets Received                           :         0

Total Packets Forwarded                          :         0

Total Packets Dropped                            :         0

Non DHCP:

Total Packets Received                           :         0

Total Packets Forwarded                          :         0

Total Packets Dropped                            :         0

DROP:

DHCP Relay not enabled                           :         0

Invalid DHCP message type                        :         0

Interface error                                  :         0

Tx failure towards server                        :         0

Tx failure towards client                        :         0

Unknown output interface                         :         0

Unknown vrf or interface for server              :         0

Max hops exceeded                                :         0

Option 82 validation failed                      :         0

Packet Malformed                                 :         0

DHCP Request dropped on MCT                      :         0

Relay Trusted port not configured                :         0

*  -  These counters will show correct value when switch

receives DHCP request packet with destination ip as broadcast

address. If request is unicast it will be HW switched

LEAF-1-vPC DHCP

Step 1. Enable the feature DCHP.

LEAF-1-VPC(config)#feature dhcp

Note: The DHCP server and the relay agent command service dhcp, ip dhcp relay, and ipv6 dhcp relay are enabled by default since NX-OS 7.x.

Step 2. Apply the command ip dhcp relay information option.

LEAF-1-VPC(config)#ip dhcp relay information option

Note: This command enables the DHCP relay agent to insert and remove Option 82 information on the packets that are forwarded.

Step 3. Apply the command “ip dhcp relay information option vpn".

LEAF-1-VPC(config)# ip dhcp relay information option vpn

Note: This command enables the DHCP relay requests that arrives on different VRF where the DHCP server belongs.

Step 4. Apply the command ip dhcp relay address [ip address of DCHP server].

Note: In this example the IP address for DCHP server is 10.10.10.150.

LEAF-1-VPC(config)#interface vlan 10

LEAF-1-VPC(config-if)#ip dhcp relay address 10.10.10.150

Step 5. Apply the command "ip dhcp relay source-interface [unique loopback]".

Note: This command configures the source IP address for DHCP relay agent to handle Discover, Offer, Request, and ACK, for unicast communication which the DHCP relay agent uses the IP address of SVI as source IP address for DHCP relay agent. This is not desired because this IP address is shared by multiples VTEPs and black-holing of DHCP packets can happen. To avoid this, a unique IP address (using a loopback interface) is necessary to differentiate each VTEP.

LEAF-1-VPC(config)#interface vlan 10

LEAF-1-VPC(config-if)# ip dhcp relay source-interface loopback100

Step 6. In the VRF corresponding tenant within BGP, direct route redistribution with a prefix-list and route-map that includes the IP address of the loopback interface.

Note: This loopback interface belongs to the tenant of SVI.

LEAF-1-VPC(config)# show running-config interface loopback 100

interface loopback100

vrf member tenant-a

ip address 172.16.10.9/32

LEAF-1-VPC(config)# ip prefix-list host_subnets seq 15 permit 172.16.10.9/32

LEAF-1-VPC(config)# route-map direct_routes_tenant-a permit 10

LEAF-1-VPC(config-route-map)# match ip address prefix-list host_subnets

LEAF-1-VPC(config-route-map)# router bgp 65000

LEAF-1-VPC(config-router)# vrf tenant-a

LEAF-1-VPC(config-router-vrf)# address-family ipv4 unicast

LEAF-1-VPC(config-router-vrf-af)# redistribute direct route-map direct_routes_tenant-a

Step 7. Verify that the IP address of the loopback interface is advertised in BGP L2VPN EVPN to the Spines with the command: show bgp l2vpn evpn [loopback IP] vrf [tenant vrf].

LEAF-1-VPC# show bgp l2vpn evpn 172.16.10.9 vrf tenant-a

BGP routing table information for VRF default, address family L2VPN EVPN

Route Distinguisher: 192.168.3.3:4    (L3VNI 303030)

BGP routing table entry for [5]:[0]:[0]:[32]:[172.16.10.9]/224, version 637

Paths: (1 available, best #1)

Flags: (0x000002) (high32 00000000) on xmit-list, is not in l2rib/evpn

Advertised path-id 1

Path type: local, path is valid, is best path, no labeled nexthop

Gateway IP: 0.0.0.0

AS-Path: NONE, path locally originated

192.168.13.1 (metric 0) from 0.0.0.0 (192.168.3.3)

Origin incomplete, MED 0, localpref 100, weight 32768

Received label 303030

Extcommunity: RT:65000:303030 ENCAP:8 Router MAC:6026.aa85.9887

Path-id 1 advertised to peers:

192.168.0.11

Step 8. Verify that the IP address of the loopback interface is injected in BGP L2VPN EVPN where DHCP server is located.

Note: If there are Nexus switches in vPC, verify that they both learn the IP address of the loopback interface in BGP L2VPN EVPN.

LEAF-1-VPC# show bgp l2vpn evpn 172.16.10.9

BGP routing table information for VRF default, address family L2VPN EVPN

Route Distinguisher: 192.168.3.3:4    (L3VNI 303030)

BGP routing table entry for [5]:[0]:[0]:[32]:[172.16.10.9]/224, version 637

Paths: (1 available, best #1)

Flags: (0x000002) (high32 00000000) on xmit-list, is not in l2rib/evpn

Advertised path-id 1

Path type: local, path is valid, is best path, no labeled nexthop

Gateway IP: 0.0.0.0

AS-Path: NONE, path locally originated

192.168.13.1 (metric 0) from 0.0.0.0 (192.168.3.3)

Origin incomplete, MED 0, localpref 100, weight 32768

Received label 303030

Extcommunity: RT:65000:303030 ENCAP:8 Router MAC:6026.aa85.9887

Path-id 1 advertised to peers:

192.168.0.11

Step 9. Verify that there is a route for the DHCP server on the source tenant with command show ip route [DHCP server IP] vrf[tenant vrf].

Note: The route entry to use must be from VxLAN to default VRF. If there is no route available, check if the VTEP locally knows the DCHP server IP address.

LEAF-1-VPC# show running-config interface vlan 10

interface Vlan10

no shutdown

vrf member tenant-a  <<<< source tenant

no ip redirects

ip address 10.10.10.1/24

no ipv6 redirects

fabric forwarding mode anycast-gateway

ip dhcp relay address 10.10.10.150

ip dhcp relay source-interface loopback100

LEAF-1-VPC# show ip route 10.10.10.150 vrf tenant-a

10.10.10.150/32, ubest/mbest: 1/0, attached

*via 10.10.10.150, Vlan10, [190/0], 6d07h, hmm

Step 10. Verify that the DCHP server IP is reachable using the loopback interface and the corresponding VRF as a VRF source with command ping [DHCP server IP] source-interface loopback [x] vrf [tenvrf].

LEAF-1-VPC# ping 10.10.10.150 source-interface loopback 100 vrf tenant-a

PING 10.10.10.150 (10.10.10.150): 56 data bytes

64 bytes from 10.10.10.150: icmp_seq=0 ttl=126 time=0.965 ms

64 bytes from 10.10.10.150: icmp_seq=1 ttl=126 time=0.57 ms

64 bytes from 10.10.10.150: icmp_seq=2 ttl=126 time=0.488 ms

64 bytes from 10.10.10.150: icmp_seq=3 ttl=126 time=0.524 ms

64 bytes from 10.10.10.150: icmp_seq=4 ttl=126 time=0.502 ms

--- 10.10.10.150 ping statistics ---

Step 11. Verify the status of the DHCP relay agent.

LEAF-1-VPC# show ip dhcp status

Current CLI Operation: show ip dhcp status

Last CLI Operation: DME: ip dhcp relay information option vpn enable

Last CLI Operation Status: SUCCESS

Step 12. Verify the option82, such as vpn option and the correct relay IP address under the relay agent.

LEAF-1-VPC# show ip dhcp relay

DHCP relay service is enabled  <<<<<<

Insertion of option 82 is enabled  <<<<<<<

Insertion of option 82 customize circuitid is disabled

TLV format in CircuitId and RemoteId suboptions is enabled

Insertion of VPN suboptions is enabled  <<<<<<<

Insertion of cisco suboptions is disabled

Global smart-relay is disabled

Relay Trusted functionality is disabled

Relay Trusted Port is Globally disabled

V4 Relay Source Address HSRP is Globally disabled

Server-ID-override-disable is disabled

Smart-relay is enabled on the following interfaces:

------------------------------------------------------

Subnet-broadcast is enabled on the following interfaces:

------------------------------------------------------

Relay Trusted Port is enabled on the following interfaces:

----------------------------------------------------------

Relay Source Address HSRP is enabled on the following interfaces:

-------------------------------------------------------------------

Helper addresses are configured on the following interfaces:

Interface        Relay Address     VRF Name

-------------    -------------     --------

Vlan10            10.10.10.150      <<<<<<<<<

Step 13. Verify the statistics of packets processed and forwaded.

LEAF-1-VPC# show ip dhcp global statistics

Packets processed 263162

Packets received through cfsoe 0

Packets forwarded 263161

Packets forwarded on cfsoe 0

Total packets dropped 0

Packets dropped from untrusted ports 0

Packets dropped due to MAC address check failure 0

Packets dropped due to Option 82 insertion failure 0

Packets dropped due to o/p intf unknown 0

Packets dropped which were unknown 0

Packets dropped due to no trusted ports 0

Packets dropped due to dhcp relay not enabled 0

Packets dropped due to no binding entry 0

Packets dropped due to interface error/no interface 0

Packets dropped due to max hops exceeded 0

Packets dropped due to Queue full 0

Step 14. Verify the statistics of relay packets.

LEAF-1-VPC# show ip dhcp relay statistics

----------------------------------------------------------------------

Message Type             Rx              Tx           Drops

----------------------------------------------------------------------

Discover                  8               7               0

Offer                 29304           29304               0

Request(*)             5029            5029               0

Ack                    6535            6535               0

Release(*)           191482          191482               0

Decline                   0               0               0

Inform(*)                 3               3               0

Nack                  29281           29281               0

----------------------------------------------------------------------

Total                261642          261641               0

----------------------------------------------------------------------

DHCP L3 FWD:

Total Packets Received                           :         0

Total Packets Forwarded                          :         0

Total Packets Dropped                            :         0

Non DHCP:

Total Packets Received                           :         0

Total Packets Forwarded                          :         0

Total Packets Dropped                            :         0

DROP:

DHCP Relay not enabled                           :         0

Invalid DHCP message type                        :         0

Interface error                                  :         0

Tx failure towards server                        :         0

Tx failure towards client                        :         0

Unknown output interface                         :         0

Unknown vrf or interface for server              :         0

Max hops exceeded                                :         0

Option 82 validation failed                      :         0

Packet Malformed                                 :         0

DHCP Request dropped on MCT                      :         0

Relay Trusted port not configured                :         0

*  -  These counters will show correct value when switch

receives DHCP request packet with destination ip as broadcast

address. If request is unicast it will be HW switched

LEAF-2-vPC DHCP

Step 1. Enable the feature DCHP.

LEAF-2-VPC(config)# feature dhcp

Note: The DHCP server and the relay agent command service dhcp, ip dhcp relay and ipv6 dhcp relay are enabled by default since NX-OS 7.x.

Step 2. Apply the command “ip dhcp relay information option”.

LEAF-2-VPC(config)# ip dhcp relay information option

Note: This command enables the DHCP relay agent to insert and remove Option 82 information on the packets that are forwarded.

Step 3. Apply the command “ip dhcp relay information option vpn".

LEAF-2-VPC(config)# ip dhcp relay information option vpn

Note: This command enables the DHCP relay requests that arrives on different VRF where the DHCP server belongs.

Step 4. Apply the command "ip dhcp relay address [ip address of DCHP server]".

Note: In this example the IP address for DCHP server is 10.10.10.150.

LEAF-2-VPC(config)# interface vlan 10

LEAF-2-VPC(config-if)# ip dhcp relay address 10.10.10.150

Step 5. Apply the command "ip dhcp relay source-interface [unique loopback]".

Note: This command configures the source IP address for DHCP relay agent to handle Discover, Offer, Request, and ACK, for unicast communication which the DHCP relay agent uses the IP address of SVI as source IP address for DHCP relay agent. This is not desired because this IP address is shared by multiples VTEPs and black-holing of DHCP packets can happen. To avoid this, a unique IP address (using a loopback interface) is necessary to differentiate each VTEP.

LEAF-2-VPC(config)# interface vlan 10

LEAF-2-VPC(config-if)# ip dhcp relay source-interface loopback 100

Step 6. In the VRF corresponding tenant within BGP, direct route redistribution with a prefix-list and route-map that includes the IP address of the loopback interface.

Note: This loopback interface belongs to the tenant of SVI.

LEAF-2-VPC(config-if)# show running-config interface loopback 100

interface loopback100

vrf member tenant-a

ip address 172.16.10.10/32

LEAF-2-VPC(config)# ip prefix-list host_subnets seq 15 permit 172.16.10.10/32

LEAF-2-VPC(config)# route-map direct_routes_tenant-a permit 10

LEAF-2-VPC(config-route-map)# match ip address prefix-list host_subnets

LEAF-2-VPC(config-route-map)# router bgp 65000

LEAF-2-VPC(config-router)# vrf tenant-a

LEAF-2-VPC(config-router-vrf)# address-family ipv4 unicast

LEAF-2-VPC(config-router-vrf-af)# redistribute direct route-map direct_routes_tenant-a

Step 7. Verify that the IP address of the loopback interface is advertised in BGP L2VPN EVPN to the Spines with the command: show bgp l2vpn evpn [loopback IP] vrf [tenant vrf].

LEAF-2-VPC(config-if)# show bgp l2vpn evpn 172.16.10.10 vrf tenant-a

BGP routing table information for VRF default, address family L2VPN EVPN

Route Distinguisher: 192.168.4.4:4    (L3VNI 303030)

BGP routing table entry for [5]:[0]:[0]:[32]:[172.16.10.10]/224, version 49

5

Paths: (1 available, best #1)

Flags: (0x000002) (high32 00000000) on xmit-list, is not in l2rib/evpn

Advertised path-id 1

Path type: local, path is valid, is best path, no labeled nexthop

Gateway IP: 0.0.0.0

AS-Path: NONE, path locally originated

192.168.13.2 (metric 0) from 0.0.0.0 (192.168.4.4)

Origin incomplete, MED 0, localpref 100, weight 32768

Received label 303030

Extcommunity: RT:65000:303030 ENCAP:8 Router MAC:6026.aa85.9587

Path-id 1 advertised to peers:

192.168.0.11 <<<<< Spine

Step 8. Verify that the IP address of the loopback interface is injected in BGP L2VPN EVPN where DHCP server is located.

Note: If there are Nexus switches in vPC, verify that they both learn the IP address of the loopback interface in BGP L2VPN EVPN.

LEAF-2-VPC(config-if)# show bgp l2vpn evpn 172.16.10.10

BGP routing table information for VRF default, address family L2VPN EVPN

Route Distinguisher: 192.168.4.4:4    (L3VNI 303030)

BGP routing table entry for [5]:[0]:[0]:[32]:[172.16.10.10]/224, version 49

5

Paths: (1 available, best #1)

Flags: (0x000002) (high32 00000000) on xmit-list, is not in l2rib/evpn

Advertised path-id 1

Path type: local, path is valid, is best path, no labeled nexthop

Gateway IP: 0.0.0.0

AS-Path: NONE, path locally originated

192.168.13.2 (metric 0) from 0.0.0.0 (192.168.4.4)

Origin incomplete, MED 0, localpref 100, weight 32768

Received label 303030

Extcommunity: RT:65000:303030 ENCAP:8 Router MAC:6026.aa85.9587

Path-id 1 advertised to peers:

192.168.0.11

Step 9. Verify that there is a route for the DHCP server on the source tenant with command show ip route [DHCP server IP] vrf[tenvrf].

Note: The route entry to use must be from VxLAN to default VRF. If there is no route available, check if the VTEP locally knows the DCHP server IP address.

LEAF-2-VPC(config-if)# show running-config interface vlan 10

interface Vlan10

no shutdown

vrf member tenant-a

no ip redirects

ip address 10.10.10.1/24

no ipv6 redirects

fabric forwarding mode anycast-gateway

ip dhcp relay address 10.10.10.150

ip dhcp relay source-interface loopback100

LEAF-2-VPC(config-if)# show ip route 10.10.10.150 vrf tenant-a

10.10.10.150/32, ubest/mbest: 1/0, attached

*via 10.10.10.150, Vlan10, [190/0], 01:01:28, hmm

Step 10. Verify that the DCHP server IP is reachable using the loopback interface and the corresponding VRF as a VRF source with command ping [DHCP server IP] source-interface loopback [x] vrf [tenant vrf].

LEAF-2-VPC(config-if)# ping 10.10.10.150 source-interface loopback 100 vrf tenant-a

PING 10.10.10.150 (10.10.10.150): 56 data bytes

64 bytes from 10.10.10.150: icmp_seq=0 ttl=127 time=0.928 ms

64 bytes from 10.10.10.150: icmp_seq=1 ttl=127 time=0.475 ms

64 bytes from 10.10.10.150: icmp_seq=2 ttl=127 time=0.455 ms

64 bytes from 10.10.10.150: icmp_seq=3 ttl=127 time=0.409 ms

64 bytes from 10.10.10.150: icmp_seq=4 ttl=127 time=0.465 ms

--- 10.10.10.150 ping statistics ---

Step 11. Verify the status of the DHCP relay agent.

LEAF-2-VPC(config)# show ip dhcp status

Current CLI Operation: show ip dhcp status

Last CLI Operation: DME: ip dhcp relay information option vpn enable

Last CLI Operation Status: SUCCESS

Step 12. Verify the option82, such as vpn option and the correct relay IP address under the relay agent.

LEAF-2-VPC(config)# show ip dhcp relay

DHCP relay service is enabled    <<<<<<<

Insertion of option 82 is enabled   <<<<<<<<<

Insertion of option 82 customize circuitid is disabled

TLV format in CircuitId and RemoteId suboptions is enabled

Insertion of VPN suboptions is enabled  <<<<<<<

Insertion of cisco suboptions is disabled

Global smart-relay is disabled

Relay Trusted functionality is disabled

Relay Trusted Port is Globally disabled

V4 Relay Source Address HSRP is Globally disabled

Server-ID-override-disable is disabled

Smart-relay is enabled on the following interfaces:

------------------------------------------------------

Subnet-broadcast is enabled on the following interfaces:

------------------------------------------------------

Relay Trusted Port is enabled on the following interfaces:

----------------------------------------------------------

Relay Source Address HSRP is enabled on the following interfaces:

-------------------------------------------------------------------

Helper addresses are configured on the following interfaces:

Interface        Relay Address     VRF Name

-------------    -------------     --------

Vlan10            10.10.10.150 <<<<

Step 13. Verify the statistics of packets processed and forwaded.

LEAF-2-VPC(config)# show ip dhcp global statistics

Packets processed 103030

Packets received through cfsoe 0

Packets forwarded 103030

Packets forwarded on cfsoe 0

Total packets dropped 0

Packets dropped from untrusted ports 0

Packets dropped due to MAC address check failure 0

Packets dropped due to Option 82 insertion failure 0

Packets dropped due to o/p intf unknown 0

Packets dropped which were unknown 0

Packets dropped due to no trusted ports 0

Packets dropped due to dhcp relay not enabled 0

Packets dropped due to no binding entry 0

Packets dropped due to interface error/no interface 0

Packets dropped due to max hops exceeded 0

Packets dropped due to Queue full 0

Step 14. Verify the statistics of relay packets.

LEAF-2-VPC# show ip dhcp relay statistics

----------------------------------------------------------------------

Message Type             Rx              Tx           Drops

----------------------------------------------------------------------

Discover              29312           29311               0

Offer                300001          300001               0

Request(*)            29324           29324               0

Ack                    1574            1574               0

Release(*)           191493          191493               0

Decline                   0               0               0

Inform(*)              1540            1540               0

Nack                 472890          472890               0

----------------------------------------------------------------------

Total               1026134         1026133               0

----------------------------------------------------------------------

DHCP L3 FWD:

Total Packets Received                           :         0

Total Packets Forwarded                          :         0

Total Packets Dropped                            :         0

Non DHCP:

Total Packets Received                           :         0

Total Packets Forwarded                          :         0

Total Packets Dropped                            :         0

DROP:

DHCP Relay not enabled                           :         0

Invalid DHCP message type                        :         0

Interface error                                  :         0

Tx failure towards server                        :         0

Tx failure towards client                        :         0

Unknown output interface                         :         0

Unknown vrf or interface for server              :         0

Max hops exceeded                                :         0

Option 82 validation failed                      :         0

Packet Malformed                                 :         0

DHCP Request dropped on MCT                      :         0

Relay Trusted port not configured                :         0

*  -  These counters will show correct value when switch

receives DHCP request packet with destination ip as broadcast

address. If request is unicast it will be HW switched

DHCP server configuration on Windows Server 2022

IP addressing scope configuration for hosts.

Step 1. Open Server Manager and validate that there are no alarms on DCHP Server in the Dashboard.

Dashboard from Server Manager on Windows Server 2022

Tip: The image enlarges when double-clicking.

Step 2. Open DHCP Server application.

DHCP Server on Windows Server 2022

Step 3. Right-click on IPv4 and click New Scope.

New Scope in DCHP

Step 4. Click Next.

Step 5. Write a Name and Description. In this example, the name is the subnet which belongs to VLAN 10 and the description is the L2VNI as L2VNI listed to VLAN 10.

Step 6. Configure the IP address range. This is the pool for hosts.

Step 6. Exclude the shared IP address from the SVI configuration in the VTEPs. In this example Interface VLAN 10 has address IP.10.10.1/24.

Warning: Failure to exclude the IP address from the SVI (or default-gateway) can cause duplication of IP addresses and impact traffic delivery.

LEAF-1# show running-config interface vlan 10

<snip>

interface Vlan10

no shutdown

vrf member tenant-a

no ip redirects

ip address 10.10.10.1/24

no ipv6 redirects

fabric forwarding mode anycast-gateway

ip dhcp relay address 10.10.10.150

ip dhcp relay source-interface loopback100

Step 7. Configure lease duration of IP address. This refers to the amount of time a host can use the assigned IP address before renewing it.

Step 8. Select Yes, I want to configure these options now.

Step 9. Configure the default-gateway IP address.

Step 10. Configure domain name and DNS server.

Step 11. Configure WINS server if applicable. This can be skipped if the information is not known.

Step 12. Select Yes, I want to activate this scope now.

Configuring scope for unique IP addresses from loopbacks in SVI as DCHP relay agent.

Step 1. Right-click on IPv4 and select IPv4Scope.

New Scope in DCHP

Step 2. Write a Name and Description. In this example, name is the subnet used for subnet with loopbacks address.

IPte: A loopback is used loopbackunique IP address throughout the VxLAN fabric for VxLAN tenant. This must be advertised in BGP L2VPN EVPN route redistribution in BGP within the VRF of the corresponding tenant in the IPv4 address-famIPv4

LEAF-1# show running-config interface loopback 100

<snip>

interface loopback100

vrf member tenant-a

ip address 172.16.10.8/32

Step 3. Configure the IP address rangeIP. This is the pool for loopbacks.

Step 4. Configure exclusions (optional because the DHCP server does lease IP addresses that belong to this subnet).

Step 5. Skip the lease duration and click Next.

Step 6. Select No, I will configure these options later.

Step 7. Click Finish.

Step 8. Right-click on the created scope and select activate.

Configuring superscope for VxLAN fabric.

Step 1. Right-click in IPv4 and select New Superscope.

Step 2. Click Next.

Step 3. Write the superscope name.

Step 4. Select all the scopes that belongs to VxLAN Fabric.

Step 5. Select all the scopes that belongs to VxLAN Fabric.

Step 6. Verify that all VxLAN fabric superscope in place and click Finish.

Configure Option 82 in host scopes.

Step 1. Right-click on Policies (last option) within the scope for host and click New Policy.

Step 2. Write a name and description and click Next.

Note: In this example, the policy is created to select IP addressing paIPicularly for hosts in Leaf-1 for VNI 101010 basedVNI Remote-ID (parameter of Option 82).

Step 3. Click Add. In Criteria, select Relay Agent Information. In Operator, select Equals. Then select Agent Remote ID and type the value. Click OK and then Next.

Note: The Remote ID is obtained from the MAC address of the SVI to which the SVII is associated.

Tip: A policy can be applied to multiple Remote-IDs (or VTEPs) by adding more conditions and selecting OR instead of AND.

LEAF-1# show interface vlan 10

Vlan10 is up, line protocol is up, autostate enabled

Hardware is EtherSVI, address is  707d.b9b8.4daf <<<<

Internet Address is 10.10.10.1/24

<snip>

Step 4. Configure the IP addressing that existing IP can use on the VTEP(s) selected by the ID and then click Next.

Note: In this example there is only one virtual machine connected to Leaf-1, so only one IP address is require IPd. Here a second IP address is addedIPn case another host connects.

Step 5. Select the box to the left of 003 Router under DCHP Standard Option. Then write the IP address of the default-gateway for the hosts that belong to this policy and press Add. Click Next.

Caution: You can select more than one option but if you are not sure which value to enter, do not do so. Inconsistent or erroneous configuration can cause unexpected behavior.

Step 6. Check the policy conditions and click Finish.

DCHP packet-walk from beginning to end in VxLAN Fabric.

Discovery send by HOST-1

Discovery on LEAF-1

Discovery received on LEAF-1

Discovery send by LEAF-1

Tip: The image enlarges when double-clicking.

Discovery on SPINE

Discovery received on SPINE

Discovery send by SPINE

Discovery on LEAF-1-vPC

Discovery received on LEAF-1-vPC

Discovery send by LEAF-1-vPC

Note: LEAF-2-vPC receives the Discovert packet but this is only switched. Destination MAC address belongs to DHCP server.

Disccovery received on DCHP Server

DCHP Offer send by DCHP Server

DCHP Offer on LEAF-2-vPC

Offer received on LEAF-2-vPC

Offer send by LEAF-2-vPC

DHCP Offer vPC SPINE

Offer received on SPINE

Offer send by SPINE

DHCP Offer on LEAF-1

Offer received on LEAF-1

Offer send on LEAF-1

DHCP Offer received on HOST-1

Request send by HOST-1

Request on LEAF-1

Request received on LEAF-1

Request send by LEAF-1

Request on SPINE

Request received on SPINE

Request send by SPINE

Request on LEAF-2-vPC

Request recevPCd on LEAF-2-vPC

Request send byvPCAF-2-vPC

Request received on DCHP Server

ACK send by DCHP Server

ACK on LEAF-2-vPC

ACK received on LEAF-2-vPC

ACK send by LEAF-2-vPC

ACK on SPINE

ACK received on SPINE

ACK send by SPINE

ACK on LEAF-1

ACK received on LEAF-1

ACK send by LEAF-1

ACK on HOST-1

Related information

Configuring VXLAN BGP EVPN

ConfiguringVXLAN

Troubleshoot DHCP Related Issues on Nexus 9000

Cisco Nexus 9000 Series NX-OS VXLAN Configuration Guide, Release 10.4(x)