Contents

Introduction

Prerequisites

Requirements

Components Used

Background Information

vPC Description and Terminology

vPC Technical Benefits

vPC Operational and Architectural Advantages

vPC Hardware and Software Redundancy Aspects

Configure vPC EVPN VXLAN

Network Diagram

Verify

Troubleshoot

Configure vPC Fabric Peering

Network Diagram

Verify

Configure Double-Sided vPC

Network Diagram

Configure Double-Sided vPC with vPC Fabric Peering

Network Diagram

Troubleshoot

Best Practices for ISSU with vPC

Strong Recommendations

Best Practices during vPC switch Replacement

Pre-Checks

Steps

Post Validation Check

vPC Considerations for VXLAN Deployment

Strong Recommendations

Related Information

Introduction

This document describes the best practices to use for virtual Port Channels (vPC) on Cisco Nexus 9000 (9k) Series Switches.

Prerequisites

Requirements

- NX-OS License Requirement for vPC

- vPC feature is included in the base NX-OS software license.

Hot Standby Router Protocol (HSRP), Virtual Router Redundancy Protocol (VRRP), Link Aggregation Control Protocol (LACP) are also included in this base license.

Layer 3 features like Open Shortest Path First (OSPF) protocol or Intermediate-System-to-Intermediate System (ISIS) protocol require LAN_ENTERPRISE_SERVICES_PKG license.

Components Used

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

- Cisco Nexus93180YC-FX that runs Release 10.2(3)

- Cisco Nexus93180YC-FX that runs Release 10.2(3)

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.

vPC Fabric Peering provides an enhanced dual-homing access solution without the overhead of waste physical ports for vPC Peer Link.

Background Information

This document applies to:

- Nexus 9k vPC

- vPC with Vxlan

- vPC Fabric Peering

- Double-Sided vPC

- Double-Sided virtual vPC

This document also covers In-Service Software Upgrade (ISSU) operations related to vPC and gives details about the latest vPC enhancements (delay restore, Network Virtual Interface (NVE) interface timers).

vPC Description and Terminology

vPC is a virtualization technology that presents both Cisco Nexus 9000 Series paired devices as a unique Layer 2 logical node to access layer devices or endpoints.

vPC belongs to Multichassis EtherChannel (MCEC) family of technology. A virtual port channel (vPC) allows links that are physically connected to two different Cisco Nexus 9000 Series devices to appear as a single port channel to a third device.

The third device can be a switch, server, or any other networking device that supports link aggregation technology.

vPC Technical Benefits

vPC provides these technical benefits:

- Eliminates Spanning Tree Protocol (STP) blocked ports.

- Uses all available uplink bandwidth.

- Allows dual-homed servers to operate in active-active mode.

- Provides fast convergence upon link or device failure.

- Offers dual active/active default gateways for servers vPC. Also leverages native split horizon/loop management provided by port-channeling technology: a packet comes a port-channel cannot immediately exit that same port-channel.

vPC Operational and Architectural Advantages

vPC offers these immediate operational and architectural advantages for users:

- Simplifies network design.

- Builds highly resilient and robust Layer 2 network.

- Enables seamless virtual machine mobility and server high-availability clusters.

- Scales available Layer 2 bandwidth, increased bisectional bandwith.

- Grows the size of the Layer 2 network.

vPC Hardware and Software Redundancy Aspects

vPC leverages both hardware and software redundancy aspects through these methods:

- vPC uses all port-channel member links available so that in case an individual link fails, hash algorithm redirects all flows to the available links.

- vPC domain is composed of two peer devices. Each peer device processes half of the traffic comes from the access layer. In case a peer device fails, the other peer device absorbs all the traffic with minimal convergence time impact.

- Each peer device in the vPC domain runs its own control plane, and both devices work independently. Any potential control plane issues stay local to the peer device and does not propagate or impact the other peer device.

From STP, vPC eliminates STP blocked ports and uses all available uplink bandwidth. STP is used as a fail safe mechanism and does not dictate L2 path for vPC-attached devices.

Within a vPC domain, a user can connect access devices in multiple ways: vPC-attached connections that leverage active/active behavior with port-channel, active/standby connectivity include STP, and single attachment without STP that runs on the access device.

Configure vPC EVPN VXLAN

Network Diagram

In the diagram, host connects to a pair of Nexus 9000 switches includes vPC domain id, but host-configured switches do not run vPC themselves. The access switch/host registers uplink as a simple port-channel without vPC knowledge.

Leaf-1

vlan 2

vn-segment 10002

vlan 10

vn-segment 10010

route-map PERMIT-ALL permit 10

vrf context test

vni 10002

rd auto

address-family ipv4 unicast

route-target both auto

route-target both auto evpn

interface nve1

no shutdown

host-reachability protocol bgp

source-interface loopback1

member vni 10002 associate-vrf

member vni 10010

suppress-arp

mcast-group 239.1.1.1

interface loopback0

ip address 10.1.1.1/32

ip router ospf 100 area 0.0.0.0

ip pim sparse-mode

no shutdown

interface loopback1

ip address 10.2.1.1/32

ip router ospf 100 area 0.0.0.0

ip pim sparse-mode

no shutdown

Leaf-2

vlan 2

vn-segment 10002

vlan 10

vn-segment 10010

route-map PERMIT-ALL permit 10

vrf context test

vni 10002

rd auto

address-family ipv4 unicast

route-target both auto

route-target both auto evpn

interface nve1

no shutdown

host-reachability protocol bgp

advertise virtual-rmac

source-interface loopback1

member vni 10002

associate-vrf member

vni 10010

suppress-arp

mcast-group 239.1.1.1

interface loopback1

ip address 10.2.1.4/32

ip address 10.2.1.10/32 secondary

ip router ospf 100 area 0.0.0.0

ip pim sparse-mode

icam monitor scale

interface loopback0

ip address 10.1.1.4/32

ip router ospf 100 area 0.0.0.0

ip pim sparse-mode

no shutdown

Leaf-2(config-if)# show run vpc

feature vpc

vpc domain 1

peer-switch

peer-keepalive destination 10.201.182.26 source 10.201.182.25

peer-gateway

ip arp synchronize

interface port-channel10

vpc peer-link

interface port-channel20

vpc 20

Leaf-3

vlan 2

vn-segment 10002

vlan 10

vn-segment 10010

route-map PERMIT-ALL permit 10

vrf context test

vni 10002

rd auto

address-family ipv4 unicast

route-target both auto

route-target both auto evpn

interface nve1

no shutdown

host-reachability protocol bgp

advertise virtual-rmac

source-interface loopback1

member vni 10002

associate-vrf member

vni 10010

suppress-arp

mcast-group 239.1.1.1

interface loopback1

ip address 10.2.1.3/32

ip address 10.2.1.10/32 secondary

ip router ospf 100 area 0.0.0.0

ip pim sparse-mode

icam monitor scale

interface loopback0

ip address 10.1.1.3/32

ip router ospf 100 area 0.0.0.0

ip pim sparse-mode

Leaf-3(config-if)# show run vpc

feature vpc

vpc domain 1

peer-switch

peer-keepalive destination 10.201.182.25 source 10.201.182.26

peer-gateway

ip arp synchronize

interface port-channel10

vpc peer-link

interface port-channel20

vpc 20

Spine-1

interface loopback0

ip address 10.3.1.1/32

ip router ospf 100 area 0.0.0.0

ip pim sparse-mode

Host-1

interface Vlan10

no shutdown

vrf member test

ip address 172.16.1.101/25

Host-2

interface Vlan10

no shutdown

vrf member test

ip address 172.16.1.102/25

Verify

Use this section to confirm that your configuration works properly.

ip interface Status for VRF "test"(3)

Interface ip Address Interface Status

Vlan10 172.16.1.102 protocol-up/link-up/admin-up

HOST-B(config)# ping 172.16.1.101 vrf test

PING 172.16.1.101 (172.16.1.101): 56 data bytes

64 bytes from 172.16.1.101: icmp_seq=0 ttl=254 time=1.326 ms

64 bytes from 172.16.1.101: icmp_seq=1 ttl=254 time=0.54 ms

64 bytes from 172.16.1.101: icmp_seq=2 ttl=254 time=0.502 ms

64 bytes from 172.16.1.101: icmp_seq=3 ttl=254 time=0.533 ms

64 bytes from 172.16.1.101: icmp_seq=4 ttl=254 time=0.47 ms

--- 172.16.1.101 ping statistics ---

5 packets transmitted, 5 packets received, 0.00% packet loss round-trip min/avg/max = 0.47/0.674/1.326 ms HOST-B(config)#

IP Interface Status for VRF "test"(3)

interface IP Address Interface Status

Vlan10 172.16.1.101 protocol-up/link-up/admin-up

Host-A(config-if)#

Host-A(config-if)# ping 172.16.1.102 vrf test

PING 172.16.1.102 (172.16.1.102): 56 data bytes

64 bytes from 172.16.1.102: icmp_seq=0 ttl=254 time=1.069 ms

64 bytes from 172.16.1.102: icmp_seq=1 ttl=254 time=0.648 ms

64 bytes from 172.16.1.102: icmp_seq=2 ttl=254 time=0.588 ms

64 bytes from 172.16.1.102: icmp_seq=3 ttl=254 time=0.521 ms

64 bytes from 172.16.1.102: icmp_seq=4 ttl=254 time=0.495 ms

--- 172.16.1.102 ping statistics ---

5 packets transmitted, 5 packets received, 0.00% packet loss round-trip min/avg/max = 0.495/0.664/1.069 ms Host-A(config-if)#

Troubleshoot

This section provides information you can use to troubleshoot your configuration.

Leaf-2(config-if)# show vpc bri

Legend:

(*) - local vPC is down, forwarding via vPC peer-link

vPC domain id : 1

Peer status : peer adjacency formed ok

vPC keep-alive status : peer is alive

Configuration consistency status : success

Per-vlan consistency status : success

Type-2 consistency status : success

vPC role : primary

Number of vPCs configured : 1

Peer Gateway : Enabled

Dual-active excluded VLANs : -

Graceful Consistency Check : Enabled

Auto-recovery status : Disabled

Delay-restore status : Timer is off.(timeout = 30s)

Delay-restore SVI status : Timer is off.(timeout = 10s)

Delay-restore Orphan-port status : Timer is off.(timeout = 0s)

Operational Layer3 Peer-router : Disabled

Virtual-peerlink mode : Disabled

vPC Peer-link status

——————————————————————————————————

id Port Status Active vlans

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

1 Po10 up 1-2,10

vPC status

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

Id Port Status Consistency Reason Active vlans

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

20 Po20 up success success 1-2,10

Please check "show vpc consistency-parameters vpc <vpc-num>" for the consistency reason of down vpc and for type-2 consistency reasons for

any vpc.

Leaf-3(config-if)# show vpc bri

Legend:

(*) - local vPC is down, forwarding via vPC peer-link

vPC domain id : 1

Peer status : peer adjacency formed ok

vPC keep-alive status : peer is alive

Configuration consistency status : success

Per-vlan consistency status : success

Type-2 consistency status : success

vPC role : secondary

Number of vPCs configured : 1

Peer Gateway : Enabled

Dual-active excluded VLANs : -

Graceful Consistency Check : Enabled

Auto-recovery status : Disabled

Delay-restore status : Timer is off.(timeout = 30s)

Delay-restore SVI status : Timer is off.(timeout = 10s)

Delay-restore Orphan-port status : Timer is off.(timeout = 0s)

Operational Layer3 Peer-router : Disabled

Virtual-peerlink mode : Disabled

vPC Peer-link status

—————————————————————————————————

id Port Status Active vlans

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

1 Po10 up 1-2,10

vPC status

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

Id Port Status Consistency Reason Active vlans

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

20 Po20 up success success 1-2,10

Please check "show vpc consistency-parameters vpc <vpc-num>" for the consistency reason of down vpc and for type-2 consistency reasons for

any vpc.

Configure vPC Fabric Peering

Network Diagram

Leaf-2

Leaf-2(config-vpc-domain)# show run vpc

feature vpc

vpc domain 1

peer-switch

peer-keepalive destination 10.201.182.26

virtual peer-link destination 10.1.1.3 source 10.1.1.4 dscp 56

peer-gateway

ip arp synchronize

interface port-channel10

vpc peer-link

interface Ethernet1/46

mtu 9216

port-type fabric

ip address 192.168.2.1/24

ip ospf network point-to-point

ip router ospf 100 area 0.0.0.0

ip pim sparse-mode

no shutdown

Leaf-3

Leaf-3(config-vpc-domain)# show run vpc

feature vpc

vpc domain 1

peer-switch

peer-keepalive destination 10.201.182.25

virtual peer-link destination 10.1.1.4 source 10.1.1.3 dscp 56

peer-gateway

ip arp synchronize

interface port-channel10

vpc peer-link

interface Ethernet1/47

mtu 9216

port-type fabric

ip address 192.168.1.1/24

ip ospf network point-to-point

ip router ospf 100 area 0.0.0.0

ip pim sparse-mode

no shutdown

Verify

Use this section in order to confirm that your configuration works properly.

show vpc brief

show vpc role

show vpc virtual-peerlink vlan consistency

show vpc fabric-ports

show vpc consistency-para global

show nve interface nve 1 detail

Configure Double-Sided vPC

Network Diagram

Leaf-2

Leaf-2(config-if-range)# show run vpc

feature vpc

vpc domain 1

peer-switch

peer-keepalive destination 10.201.182.26 source 10.201.182.25

peer-gateway

ip arp synchronize

interface port-channel10

vpc peer-link

interface port-channel20

vpc 20

interface port-channel40

vpc 40

Leaf-3

Leaf-3(config-if-range)# show run vpc

feature vpc

vpc domain 1

peer-switch

peer-keepalive destination 10.201.182.25 source 10.201.182.26

peer-gateway

ip arp synchronize

interface port-channel10

vpc peer-link

interface port-channel20

vpc 20

interface port-channel40

vpc 40

Leaf-4

Leaf-4(config-if)# show run vpc

feature vpc

vpc domain 2

peer-switch

peer-keepalive destination 10.201.182.29 source 10.201.182.28

peer-gateway

interface port-channel10

vpc peer-link

interface port-channel20

vpc 20

interface port-channel40

vpc 40

Leaf-5

Leaf-5(config-if)# show running-config vpc

feature vpc

vpc domain 2

peer-switch

peer-keepalive destination 10.201.182.28 source 10.201.182.29

peer-gateway

interface port-channel10

vpc peer-link

interface port-channel20

vpc 20

interface port-channel40

vpc 40

Configure Double-Sided vPC with vPC Fabric Peering

Network Diagram

In double-sided vPC, both the Nexus 9000 switches run vPC. Each vPC pair of Nexus 9000 switches is connected to the aggregation vPC pair with a unique vPC.

Leaf-2

Leaf-2(config-if-range)# show run vpc

feature vpc

vpc domain 1

peer-switch

peer-keepalive destination 10.201.182.26

virtual peer-link destination 10.1.1.3 source 10.1.1.4 dscp 56

peer-gateway

ip arp synchronize

interface port-channel10

vpc peer-link

interface port-channel20

vpc 20

interface port-channel40

vpc 40

Leaf-3

Leaf-3(config-if-range)# show run vpc

feature vpc

vpc domain 1

peer-switch

peer-keepalive destination 10.201.182.25

virtual peer-link destination 10.1.1.4 source 10.1.1.3 dscp 56

peer-gateway

ip arp synchronize

interface port-channel10

vpc peer-link

interface port-channel20

vpc 20

interface port-channel40

vpc 40

Leaf-4 and Leaf-5 configuration is similar as double-sided vPC.

Troubleshoot

This section provides information you can use in order to troubleshoot your configuration.

Leaf-4(config-if)# show spanning-tree

VLAN0010

Spanning tree enabled protocol rstp

Root ID    Priority    32778

Address     0023.04ee.be01

Cost        5

Port        4105 (port-channel10)

Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Bridge ID  Priority    32778  (priority 32768 sys-id-ext 10)

Address     0023.04ee.be02

Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type

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

Po10             Root FWD 4         128.4105 (vPC peer-link) Network P2p

Po20             Desg FWD 1         128.4115 (vPC) P2p

Po40             Root FWD 1         128.4135 (vPC) P2p

VLAN0020

Spanning tree enabled protocol rstp

Root ID    Priority    32788

Address     0023.04ee.be02

This bridge is the root

Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Bridge ID  Priority    32788  (priority 32768 sys-id-ext 20)

Address     0023.04ee.be02

Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type

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

Po10             Root FWD 4         128.4105 (vPC peer-link) Network P2p

Po20             Desg FWD 1         128.4115 (vPC) P2p

Po40             Desg FWD 1         128.4135 (vPC) P2p

Leaf-5(config-if)# show spanning-tree

VLAN0010

Spanning tree enabled protocol rstp

Root ID    Priority    32778

Address     0023.04ee.be01

Cost        1

Port        4135 (port-channel40)

Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Bridge ID  Priority    32778  (priority 32768 sys-id-ext 10)

Address     0023.04ee.be02

Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type

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

Po10             Desg FWD 4         128.4105 (vPC peer-link) Network P2p

Po20             Desg FWD 1         128.4115 (vPC) P2p

Po40             Root FWD 1         128.4135 (vPC) P2p

VLAN0020

Spanning tree enabled protocol rstp

Root ID    Priority    32788

Address     0023.04ee.be02

This bridge is the root

Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Bridge ID  Priority    32788  (priority 32768 sys-id-ext 20)

Address     0023.04ee.be02

Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type

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

Po10             Desg FWD 4         128.4105 (vPC peer-link) Network P2p

Po20             Desg FWD 1         128.4115 (vPC) P2p

Po40             Desg FWD 1         128.4135 (vPC) P2p

Leaf-5(config-if)#

Leaf-2(config-if-range)# show spanning-tree

VLAN0001

Spanning tree enabled protocol rstp

Root ID    Priority    32769

Address     0023.04ee.be01

Cost        0

Port        0 ()

Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Bridge ID  Priority    32769  (priority 32768 sys-id-ext 1)

Address     003a.9c28.2cc7

Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type

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

Eth1/47          Desg FWD 4         128.185  P2p

VLAN0010

Spanning tree enabled protocol rstp

Root ID    Priority    32778

Address     0023.04ee.be01

This bridge is the root

Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Bridge ID  Priority    32778  (priority 32768 sys-id-ext 10)

Address     0023.04ee.be01

Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type

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

Po10             Desg FWD 4         128.4105 (vPC peer-link) Network P2p

Po40             Desg FWD 1         128.4135 (vPC) P2p

Eth1/47          Desg FWD 4         128.185  P2p

Leaf-2(config-if-range)#

Leaf-3(config-if-range)# show spanning-tree

VLAN0010

Spanning tree enabled protocol rstp

Root ID    Priority    32778

Address     0023.04ee.be01

This bridge is the root

Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Bridge ID  Priority    32778  (priority 32768 sys-id-ext 10)

Address     0023.04ee.be01

Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type

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

Po10             Root FWD 4         128.4105 (vPC peer-link) Network P2p

Po40             Desg FWD 1         128.4135 (vPC) P2p

Leaf-3(config-if-range)#

Best Practices for ISSU with vPC

This section describes the best practices for the non-disruptive software upgrade, use Cisco ISSU when a vPC domain is configured. vPC System NX-OS Upgrade (or Downgrade) vPC feature is fully compatible with Cisco ISSU.

In a vPC environment, ISSU is the recommended method to upgrade the system. The vPC system can be independently upgraded with no disruption to traffic. The upgrade is serialized and must be run one at a time. The configuration lock during ISSU prevents synchronous upgrades on both vPC peer devices to happen (configuration is automatically locked on other vPC peer device when ISSU is initiated). To perform ISSU operation, 1 single knob is needed.

Note: vPC with FEX (host vPC) also fully supports ISSU. There is zero packet loss when the upgraded vPC domain has FEX. Server dual-attached to 2 different FEX through a standard port-channel is not aware that the upgrade operation occurs in the network.

switch#install all nxos bootflash:<image name>

Strong Recommendations

vPC peer device 1, 9K1 (loads the code first on primary or secondary vPC peer device has no importance) use ISSU. Note that other vPC peer device (9K2) has its configuration locked to protect against any operation on the switch.

- Use ISSU (In-Service Software Upgrade) to change NX-OS code release for vPC domain. Perform the operation sequentially, one vPC peer device at a time.

- Refer to NX-OS release notes to select correctly the target NX-OS code release based on device code (ISSU compatibility matrix)

Note: Upgrade 9k1 from 7.x to 9.3.8/9.3.9 caused 40g port down on vPC. If peer-link is connected with 40 G, it is recommended to upgrade both switches into 9.3.8/9.3.9 to bring 40G up or path needs to follow: I7(7) – 9.3(1) – 9.3(9).

Best Practices during vPC switch Replacement

Pre-Checks

show version

show module

show spanning-tree summary

show vlan summary

show ip interface brief

show port-channel summary

show vpc

show vpc brief

show vpc role

show vpc peer-keepalives

show vpc statistics peer-keepalive

show vpc consistency-parameters global

show vpc consistency-parameters interface port-channel<>

show vpc consistency-parameters vlans

show run vpc all

show hsrp brief

show hsrp

show run hsrp

show hsrp interface vlan <vlan_number>

Show vrrp

Show vrrp brief

Show vrrp interface vlan <vlan_number>

Show run vrrp

Steps

1. Shut down all vPC member ports one by one.

2. Shut down all orphan ports.

3. Shut down all Layer 3 physical links one by one.

4. Shut down the vPC Peer Keep Alive (PKA) link.

5. Shut down the vPC Peer-link.

6. Ensure that all the ports are down on the problematic switch.

7. Ensure the traffic is diverted to the Redundant switch via shared commands on the redundant switch.

show vpc

show vpc statistics

show ip route vrf all summary

show ip mroute vrf all summary

show ip interface brief

show interface status

show port-channel summary

show hsrp brief

Show vrrp brief

8. Ensure the replacement device is set up with the correct image and license.

show version

show module

show diagnostic results module all detail

show license

show license usage

show system internal mts buffer summary|detail

show logging logfile

show logging nvram

9. Configure the switch with the backup configuration correctly.

10. If auto-recovery is enabled, disable it during replacement.

Leaf-2(config)# vpc domain 1

Leaf-2(config-vpc-domain)# no auto-recovery

Leaf-2(config-if)# show vpc bri

Legend:

(*) - local vPC is down, forwarding via vPC peer-link

vPC domain id : 1

Peer status : peer adjacency formed ok

vPC keep-alive status : peer is alive

Configuration consistency status : success

Per-vlan consistency status : success

Type-2 consistency status : success

vPC role : primary

Number of vPCs configured : 1

Peer Gateway : Enabled

Dual-active excluded VLANs : -
Graceful Consistency Check : Enabled

Auto-recovery status : Disabled

Delay-restore status : Timer is off. (timeout = 30s)

Delay-restore SVI status : Timer is off (timeout = 10s)

Delay-restore Orphan-port status : Timer is off.(timeout = 0s)

Operational Layer3 Peer-router : Disabled

Virtual-peerlink mode : Disabled

11. Ensure the Sticky bit is set to False.

Leaf-5(config-vpc-domain)# show sys internal vpcm info all | i i stick

OOB Peer Version: 2 OOB peer was alive: TRUE Sticky Master: FALSE

12. If the Sticky bit is set to True, reconfigure the vPC role priority. This means to reapply the original configuration for the role priority.

- vPC domain 1     <==  1 is vPC domain number mentioned on the original switch

- role priority 2000   <== example: if 2000 is vPC role priority set on original switch

13. Bring up the interfaces strictly in this order:

1. Bring up the Peer Keep-alive Link.

2. Bring up the vPC peer-link.

3. Confirm that the vPC role established correctly.

4. Bring up rest of the interfaces on the switches one by one in this order:

1. vPC member ports

2. Orphan ports (Non-vPC ports)

3. Layer-3 physical interface

Post Validation Check

show version

show module

show diagnostics result module all detail

show environment

show license usage

show interface status

show ip interface brief

show interface status err-disabled

show cdp neighbors

show redundancy status

show spanning-tree summary

show port-channel summary

show vpc

show vpc brief

show vpc role

show vpc peer-keepalives

show vpc statistics peer-keepalive

show vpc consistency-parameters global

show vpc consistency-parameters interface port-channel1

show vpc consistency-parameters vlans

show hsrp brief

show vrrp brief

vPC Considerations for VXLAN Deployment

- On vPC VXLAN, it is recommended to increase the delay restore interface-vlan timer under the vPC configuration, if the number of SVIs are scaled up. For example, if there are 1000 VNIs with 1000 SVIs, it is recommended to increase the delay restore interface-vlan timer to 45 seconds.

switch(config-vpc-domain)# delay restore interface-vlan 45

- For vPC, the loopback interface has two IP addresses: the primary IP address and the secondary IP address.

- The primary IP address is unique and is used by Layer 3 protocols.

- The secondary IP address on loopback is necessary because the interface NVE uses it for the VTEP IP address. The secondary IP address must be same on both vPC peers.

- NVE Hold-Down timer needs to be higher than vPC delay restore timer.
Leaf-2(config-if-range)# show nve interface nve 1 detail

Interface: nve1, State: Up, encapsulation: VXLAN

VPC Capability: VPC-VIP-Only [notified]

Local Router MAC: 003a.9c28.2cc7

Host Learning Mode: Control-Plane

Source-Interface: loopback1 (primary: 10.1.1.41.1.4, secondary: 10.1.1.10)

Source Interface State: Up

Virtual RMAC Advertisement: Yes

NVE Flags:

Interface Handle: 0x49000001

Source Interface hold-down-time: 180

Source Interface hold-up-time: 30

Remaining hold-down time: 0 seconds

Virtual Router MAC: 0200.1401.010a

Interface state: nve-intf-add-complete

Fabric convergence time: 135 seconds

Fabric convergence time left: 0 seconds

- For best practices, enable auto-recovery in your vPC environment. Although rare, there is a chance that vPC auto-recovery feature can get you in dual active scenario.

- The vPC Peer-Switch feature allows a pair of vPC peer devices to appear as a single Spanning Tree Protocol root in the Layer 2 topology (they have the same bridge ID). vPC peer-switch must be configured on both vPC peer devices to become operational. The command is:

N9K(config-vpc-domain)# peer-switch

- vPC Peer-Gateway allows a vPC peer device to act as the active gateway for packets addressed to the other peer device router MAC. It keeps the forwarding of traffic local to the vPC peer device and avoids use of the peer-link. There is no impact on traffic and functionality when it activates the Peer-Gateway capability.

N9k-1(config)# vpc domain 1

N9k-1(config-vpc-domain)# peer-gateway

- Layer3 peer-router command has been introduced which enables routing over the vPC.

N9k-1(config)# vpc domain 1

N9k-1(config-vpc-domain)# layer3 peer-router

N9K-1(config-vpc-domain)# exit

N9K-1# sh vpc

Legend:(*)

- local vPC is down, forwarding via vPC peer-link

vPC domain id : 100

Peer status : peer adjacency formed ok

vPC keep-alive status : peer is alive

Configuration consistency status : success

Per-vlan consistency status : success

Type-2 consistency status : success

vPC role : secondary, operational primary

Number of vPCs configured : 2

Peer Gateway : Enabled

Peer gateway excluded VLANs : -

Peer gateway excluded bridge-domains : -

Dual-active excluded VLANs and BDs : -

Graceful Consistency Check : Enabled

Auto-recovery status : Enabled (timeout = 240 seconds)

Operational Layer3 Peer-router : Enabled

Strong Recommendations

- Peer-gateway must be enabled before Layer 3 peer-router.

- Both vPC peers must have Layer 3 peer-router configured in order to take effect.

- Enable Supress-arp as a best practice while multicast ip address for VXLAN.

- Use separate loopback ip address for control and dataplane in vPC VXLAN fabric.

- In vPC with MSTP, bridge priority must be the same on both vPC peers.

- For best convergence results, fine tune vPC delay restore and NVE interface holddown timers.

Related Information

- Nexus 9000 Series Switches Documentation

- Cisco Nexus 9000 Series NX-OS Interfaces Configuration Guide, Release 9.3(x)

- Cisco Nexus 9000 Series NX-OS Verified Scalability Guide, Release 9.2(1) - includes vPC scalability numbers (CCO)

- Recommended Cisco NX-OS Releases for Cisco Nexus 9000 Series Switches

- Nexus 9000 Series Switches Release Notes

- Cisco Nexus 9000 Series NX-OS VXLAN Configuration Guide, Release 9.2(x) - section on vPC Fabric Peering

- Configure EVPN Vxlan IPV6 Overlay Configuration Example

- Design and Configuration Guide: Best Practices for Virtual Port Channels (vPC) on Cisco Nexus 7000 Series Switches - N7k and N9k vPC theory is similar and this reference covers addition information about best practices

- Configure and Verify Double-sided Virtual vPC