Configuring Virtual Port Channels

Information About vPCs

vPC Overview

A virtual port channel (vPC) allows links that are physically connected to two Cisco Nexus devices or Cisco Nexus Fabric Extenders to appear as a single port channel by a third device (see the following figure). The third device can be a switch, server, or any other networking device. You can configure vPCs in topologies that include Cisco Nexus devices connected to Cisco Nexus Fabric Extenders. A vPC can provide multipathing, which allows you to create redundancy by enabling multiple parallel paths between nodes and load balancing traffic where alternative paths exist.

You configure the EtherChannels by using one of the following:

  • No protocol
  • Link Aggregation Control Protocol (LACP)

When you configure the EtherChannels in a vPC—including the vPC peer link channel—each switch can have up to 16 active links in a single EtherChannel.


Note

You must enable the vPC feature before you can configure or run the vPC functionality.

To enable the vPC functionality, you must create a peer-keepalive link and a peer-link under the vPC domain for the two vPC peer switches to provide the vPC functionality.

To create a vPC peer link you configure an EtherChannel on one Cisco Nexus device by using two or more Ethernet ports. On the other switch, you configure another EtherChannel again using two or more Ethernet ports. Connecting these two EtherChannels together creates a vPC peer link.


Note

We recommend that you configure the vPC peer-link EtherChannels as trunks.

The vPC domain includes both vPC peer devices, the vPC peer-keepalive link, the vPC peer link, and all of the EtherChannels in the vPC domain connected to the downstream device. You can have only one vPC domain ID on each vPC peer device.


Note

Always attach all vPC devices using EtherChannels to both vPC peer devices.

A vPC provides the following benefits:

  • Allows a single device to use an EtherChannel across two upstream devices
  • Eliminates Spanning Tree Protocol (STP) blocked ports
  • Provides a loop-free topology
  • Uses all available uplink bandwidth
  • Provides fast convergence if either the link or a switch fails
  • Provides link-level resiliency
  • Assures high availability

Terminology

vPC Terminology

The terminology used in vPCs is as follows:

  • vPC—combined EtherChannel between the vPC peer devices and the downstream device.

  • vPC peer device—One of a pair of devices that are connected with the special EtherChannel known as the vPC peer link.

  • vPC peer link—link used to synchronize states between the vPC peer devices.

  • vPC member port—Interfaces that belong to the vPCs.

  • vPC domain—domain that includes both vPC peer devices, the vPC peer-keepalive link, and all of the port channels in the vPC connected to the downstream devices. It is also associated to the configuration mode that you must use to assign vPC global parameters. The vPC domain ID must be the same on both switches.

  • vPC peer-keepalive link—The peer-keepalive link monitors the vitality of a vPC peer Cisco Nexus device. The peer-keepalive link sends configurable, periodic keepalive messages between vPC peer devices.

    No data or synchronization traffic moves over the vPC peer-keepalive link; the only traffic on this link is a message that indicates that the originating switch is operating and running vPCs.

vPC Domain

To create a vPC domain, you must first create a vPC domain ID on each vPC peer switch using a number from 1 to 1000. This ID must be the same on a set of vPC peer devices.

You can configure the EtherChannels and vPC peer links by using LACP or no protocol. When possible, we recommend that you use LACP on the peer-link, because LACP provides configuration checks against a configuration mismatch on the EtherChannel.

The vPC peer switches use the vPC domain ID that you configure to automatically assign a unique vPC system MAC address. Each vPC domain has a unique MAC address that is used as a unique identifier for the specific vPC-related operations, although the switches use the vPC system MAC addresses only for link-scope operations, such as LACP. We recommend that you create each vPC domain within the contiguous network with a unique domain ID. You can also configure a specific MAC address for the vPC domain, rather than having the Cisco NX-OS software assign the address.

The vPC peer switches use the vPC domain ID that you configure to automatically assign a unique vPC system MAC address. The switches use the vPC system MAC addresses only for link-scope operations, such as LACP or BPDUs. You can also configure a specific MAC address for the vPC domain.

We recommend that you configure the same VPC domain ID on both peers and, the domain ID should be unique in the network. For example, if there are two different VPCs (one in access and one in aggregation) then each vPC should have a unique domain ID.

After you create a vPC domain, the Cisco NX-OS software automatically creates a system priority for the vPC domain. You can also manually configure a specific system priority for the vPC domain.


Note

If you manually configure the system priority, you must ensure that you assign the same priority value on both vPC peer switches. If the vPC peer switches have different system priority values, the vPC will not come up.

Peer-Keepalive Link and Messages

The Cisco NX-OS software uses a peer-keepalive link between the vPC peers to transmit periodic, configurable keepalive messages. You must have Layer 3 connectivity between the peer switches to transmit these messages; the system cannot bring up the vPC peer link unless a peer-keepalive link is already up and running.

If one of the vPC peer switches fails, the vPC peer switch on the other side of the vPC peer link senses the failure when it does not receive any peer-keepalive messages. The default interval time for the vPC peer-keepalive message is 1 second. You can configure the interval between 400 milliseconds and 10 seconds. You can also configure a timeout value with a range of 3 to 20 seconds; the default timeout value is 5 seconds. The peer-keepalive status is checked only when the peer-link goes down.

The vPC peer-keepalive can be carried either in the management or default VRF on the Cisco Nexus device. When you configure the switches to use the management VRF, the source and destination for the keepalive messages are the mgmt 0 interface IP addresses. When you configure the switches to use the default VRF, an SVI must be created to act as the source and destination addresses for the vPC peer-keepalive messages. Ensure that both the source and destination IP addresses used for the peer-keepalive messages are unique in your network and these IP addresses are reachable from the VRF associated with the vPC peer-keepalive link.


Note

We recommend that you configure the vPC peer-keepalive link on the Cisco Nexus device to run in the management VRF using the mgmt 0 interfaces. If you configure the default VRF, ensure that the vPC peer link is not used to carry the vPC peer-keepalive messages.

Compatibility Parameters for vPC Peer Links

Many configuration and operational parameters must be identical on all interfaces in the vPC. After you enable the vPC feature and configure the peer link on both vPC peer switches, Cisco Fabric Services (CFS) messages provide a copy of the configuration on the local vPC peer switch configuration to the remote vPC peer switch. The system then determines whether any of the crucial configuration parameters differ on the two switches.

Enter the show vpc consistency-parameters command to display the configured values on all interfaces in the vPC. The displayed configurations are only those configurations that would limit the vPC peer link and vPC from coming up.

The compatibility check process for vPCs differs from the compatibility check for regular EtherChannels.

New Type 2 Consistency Check on the vPC Port-Channels

A new type 2 consistency check has been added to validate the switchport mac learn settings on the vPC port-channels. The CLI show vpc consistency-check vPC <vpc no.> has been enhanced to display the local and peer values of the switchport mac-learn configuration. Because it is a type 2 check, vPC is operationally up even if there is a mismatch between the local and the peer values, but the mismatch can be displayed from the CLI output. 

switch# sh vpc consistency-parameters vpc 1112
 
    Legend:
        Type 1 : vPC will be suspended in case of mismatch
 
Name                                 Type            Local Value                 Peer Value
-------------                        ----            ----------------------     -----------------------
Shut Lan                             1               No                         No
STP Port Type                        1               Default                     Default
STP Port Guard                       1               None                        None
STP MST Simulate PVST                1               Default                     Default
nve configuration                    1               nve                        nve
lag-id                               1               [(fa0,                      [(fa0,
                                                     0-23-4-ee-be-64, 8458,     0-23-4-ee-be-64, 8458,
                                                     0, 0), (8000,              0, 0), (8000,
                                                     f4-4e-5-84-5e-3c, 457,     f4-4e-5-84-5e-3c, 457,
                                                     0, 0)]                     0, 0)]
mode                                 1               active                      active
Speed                                1               10 Gb/s                    10 Gb/s
Duplex                               1               full                        full
Port Mode                            1               trunk                       trunk
Native Vlan                          1               1                          1
MTU                                  1               1500                        1500
Admin port mode                      1
Switchport MAC Learn                 2               Enable                     Disable> Newly added consistency parameter
vPC card type                        1               Empty                      Empty
Allowed VLANs                        -               311-400                     311-400
Local suspended VLANs                -               -

Configuration Parameters That Must Be Identical

The configuration parameters in this section must be configured identically on both switches at either end of the vPC peer link.


Note

You must ensure that all interfaces in the vPC have the identical operational and configuration parameters listed in this section.

Enter the show vpc consistency-parameters command to display the configured values on all interfaces in the vPC. The displayed configurations are only those configurations that would limit the vPC peer link and vPC from coming up.

The switch automatically checks for compatibility of these parameters on the vPC interfaces. The per-interface parameters must be consistent per interface, and the global parameters must be consistent globally.

  • Port-channel mode: on, off, or active
  • Link speed per channel
  • Duplex mode per channel
  • Trunk mode per channel:
    • Native VLAN
    • VLANs allowed on trunk
    • Tagging of native VLAN traffic
  • Spanning Tree Protocol (STP) mode
  • STP region configuration for Multiple Spanning Tree (MST)
  • Enable or disable state per VLAN
  • STP global settings:
    • Bridge Assurance setting
    • Port type setting—We recommend that you set all vPC interfaces as normal ports
    • Loop Guard settings
  • STP interface settings:
    • Port type setting
    • Loop Guard
    • Root Guard

If any of these parameters are not enabled or defined on either switch, the vPC consistency check ignores those parameters.


Note

To ensure that none of the vPC interfaces are in the suspend mode, enter the show vpc brief and show vpc consistency-parameters commands and check the syslog messages.

Configuration Parameters That Should Be Identical

When any of the following parameters are not configured identically on both vPC peer switches, a misconfiguration might cause undesirable behavior in the traffic flow:

  • MAC aging timers
  • Static MAC entries
  • VLAN interface—Each switch on the end of the vPC peer link must have a VLAN interface configured for the same VLAN on both ends and they must be in the same administrative and operational mode. Those VLANs configured on only one switch of the peer link do not pass traffic using the vPC or peer link. You must create all VLANs on both the primary and secondary vPC switches, or the VLAN will be suspended.
  • Private VLAN configuration
  • All ACL configurations and parameters
  • Quality of service (QoS) configuration and parameters—Local parameters; global parameters must be identical
  • STP interface settings:
    • BPDU Filter
    • BPDU Guard
    • Cost
    • Link type
    • Priority
    • VLANs (Rapid PVST+)

To ensure that all the configuration parameters are compatible, we recommend that you display the configurations for each vPC peer switch once you configure the vPC.

Per-VLAN Consistency Check

Type-1 consistency checks are performed on a per-VLAN basis when spanning tree is enabled or disabled on a VLAN. VLANs that do not pass the consistency check are brought down on both the primary and secondary switches while other VLANs are not affected.

vPC Auto-Recovery

When both vPC peer switches reload and only one switch reboots, auto-recovery allows that switch to assume the role of the primary switch and the vPC links will be allowed to come up after a predetermined period of time. The reload delay period in this scenario can range from 240 to 3600 seconds.

When vPCs are disabled on a secondary vPC switch due to a peer-link failure and then the primary vPC switch fails or is unable to forward traffic, the secondary switch reenables the vPCs. In this scenario, the vPC waits for three consecutive keepalive failures to recover the vPC links.

The vPC auto-recovery feature is disabled by default.

vPC Peer Links

A vPC peer link is the link that is used to synchronize the states between the vPC peer devices.


Note

You must configure the peer-keepalive link before you configure the vPC peer link or the peer link will not come up.

vPC Peer Link Overview

You can have only two switches as vPC peers; each switch can serve as a vPC peer to only one other vPC peer. The vPC peer switches can also have non-vPC links to other switches.

To make a valid configuration, you configure an EtherChannel on each switch and then configure the vPC domain. You assign the EtherChannel on each switch as a peer link. For redundancy, we recommend that you should configure at least two dedicated ports into the EtherChannel; if one of the interfaces in the vPC peer link fails, the switch automatically falls back to use another interface in the peer link.


Note

We recommend that you configure the EtherChannels in trunk mode.

Many operational parameters and configuration parameters must be the same in each switch connected by a vPC peer link. Because each switch is completely independent on the management plane, you must ensure that the switches are compatible on the critical parameters. vPC peer switches have separate control planes. After configuring the vPC peer link, you should display the configuration on each vPC peer switch to ensure that the configurations are compatible.


Note

You must ensure that the two switches connected by the vPC peer link have certain identical operational and configuration parameters.

When you configure the vPC peer link, the vPC peer switches negotiate that one of the connected switches is the primary switch and the other connected switch is the secondary switch. By default, the Cisco NX-OS software uses the lowest MAC address to elect the primary switch. The software takes different actions on each switch—that is, the primary and secondary—only in certain failover conditions. If the primary switch fails, the secondary switch becomes the operational primary switch when the system recovers, and the previously primary switch is now the secondary switch.

You can also configure which of the vPC switches is the primary switch. If you want to configure the role priority again to make one vPC switch the primary switch, configure the role priority on both the primary and secondary vPC switches with the appropriate values, shut down the EtherChannel that is the vPC peer link on both switches by entering the shutdown command, and reenable the EtherChannel on both switches by entering the no shutdown command.

MAC addresses that are learned over vPC links are also synchronized between the peers.

Configuration information flows across the vPC peer links using the Cisco Fabric Services over Ethernet (CFSoE) protocol. All MAC addresses for those VLANs configured on both switches are synchronized between vPC peer switches. The software uses CFSoE for this synchronization.

If the vPC peer link fails, the software checks the status of the remote vPC peer switch using the peer-keepalive link, which is a link between vPC peer switches, to ensure that both switches are up. If the vPC peer switch is up, the secondary vPC switch disables all vPC ports on its switch. The data then forwards down the remaining active links of the EtherChannel.

The software learns of a vPC peer switch failure when the keepalive messages are not returned over the peer-keepalive link.

Use a separate link (vPC peer-keepalive link) to send configurable keepalive messages between the vPC peer switches. The keepalive messages on the vPC peer-keepalive link determines whether a failure is on the vPC peer link only or on the vPC peer switch. The keepalive messages are used only when all the links in the peer link fail.

vPC Number

Once you have created the vPC domain ID and the vPC peer link, you can create EtherChannels to attach the downstream switch to each vPC peer switch. That is, you create one single EtherChannel on the downstream switch with half of the ports to the primary vPC peer switch and the other half of the ports to the secondary peer switch.

On each vPC peer switch, you assign the same vPC number to the EtherChannel that connects to the downstream switch. You will experience minimal traffic disruption when you are creating vPCs. To simplify the configuration, you can assign the vPC ID number for each EtherChannel to be the same as the EtherChannel itself (that is, vPC ID 10 for EtherChannel 10).


Note

The vPC number that you assign to the EtherChannel that connects to the downstream switch from the vPC peer switch must be identical on both vPC peer switches.

vPC Interactions with Other Features

vPC and LACP

The Link Aggregation Control Protocol (LACP) uses the system MAC address of the vPC domain to form the LACP Aggregation Group (LAG) ID for the vPC.

You can use LACP on all the vPC EtherChannels, including those channels from the downstream switch. We recommend that you configure LACP with active mode on the interfaces on each EtherChannel on the vPC peer switches. This configuration allows you to more easily detect compatibility between switches, unidirectional links, and multihop connections, and provides dynamic reaction to run-time changes and link failures.

The vPC peer link supports 16 EtherChannel interfaces.


Note

When you manually configure the system priority, you must ensure that you assign the same priority value on both vPC peer switches. If the vPC peer switches have different system priority values, vPC does not come up.

vPC Peer Links and STP

When you first bring up the vPC functionality, STP reconverges. STP treats the vPC peer link as a special link and always includes the vPC peer link in the STP active topology.

We recommend that you set all the vPC peer link interfaces to the STP network port type so that Bridge Assurance is automatically enabled on all vPC peer links. We also recommend that you do not enable any of the STP enhancement features on VPC peer links.

You must configure a list of parameters to be identical on the vPC peer switches on both sides of the vPC peer link.

STP is distributed; that is, the protocol continues running on both vPC peer switches. However, the configuration on the vPC peer switch elected as the primary switch controls the STP process for the vPC interfaces on the secondary vPC peer switch.

The primary vPC switch synchronizes the STP state on the vPC secondary peer switch using Cisco Fabric Services over Ethernet (CFSoE).

The vPC manager performs a proposal/handshake agreement between the vPC peer switches that sets the primary and secondary switches and coordinates the two switches for STP. The primary vPC peer switch then controls the STP protocol for vPC interfaces on both the primary and secondary switches.

The Bridge Protocol Data Units (BPDUs) use the MAC address set for the vPC for the STP bridge ID in the designated bridge ID field. The vPC primary switch sends these BPDUs on the vPC interfaces.


Note

Display the configuration on both sides of the vPC peer link to ensure that the settings are identical. Use the show spanning-tree command to display information about the vPC.

CFSoE

The Cisco Fabric Services over Ethernet (CFSoE) is a reliable state transport mechanism that you can use to synchronize the actions of the vPC peer devices. CFSoE carries messages and packets for many features linked with vPC, such as STP and IGMP. Information is carried in CFS/CFSoE protocol data units (PDUs).

When you enable the vPC feature, the device automatically enables CFSoE, and you do not have to configure anything. CFSoE distributions for vPCs do not need the capabilities to distribute over IP or the CFS regions. You do not need to configure anything for the CFSoE feature to work correctly on vPCs.

You can use the show mac address-table command to display the MAC addresses that CFSoE synchronizes for the vPC peer link.


Note

Do not enter the no cfs eth distribute or the no cfs distribute command. CFSoE must be enabled for vPC functionality. If you do enter either of these commands when vPC is enabled, the system displays an error message.

When you enter the show cfs application command, the output displays "Physical-eth," which shows the applications that are using CFSoE.

Guidelines and Limitations for vPCs

vPCs have the following configuration guidelines and limitations:

  • vPC is not supported between different types of Cisco Nexus 3000 Series switches.

  • VPC peers should have same reserved VLANs for VXLAN. Different reserved VLANs on the peers may lead to undesired behavior with VXLAN.

  • The output of the sh vpc brief CLI command displays two additional fields, Delay-restore status and Delay-restore SVI status.

  • vPC is not qualified with IPv6.

  • You must enable the vPC feature before you can configure vPC peer-link and vPC interfaces.

  • You must configure the peer-keepalive link before the system can form the vPC peer link.

  • The vPC peer-link needs to be formed using a minimum of two 10-Gigabit Ethernet interfaces.

  • We recommend that you configure the same vPC domain ID on both peers and the domain ID should be unique in the network. For example, if there are two different vPCs (one in access and one in aggregation) then each vPC should have a unique domain ID.

  • Only port channels can be in vPCs. A vPC can be configured on a normal port channel (switch-to-switch vPC topology) and on a port channel host interface (host interface vPC topology).

  • You must configure both vPC peer switches; the configuration is not automatically synchronized between the vPC peer devices.

  • Check that the necessary configuration parameters are compatible on both sides of the vPC peer link.

  • You might experience minimal traffic disruption while configuring vPCs.

  • You should configure all port channels in the vPC using LACP with the interfaces in active mode.

  • You might experience traffic disruption when the first member of a vPC is brought up.

  • OSPF over vPC and BFD with OSPF are supported on Cisco Nexus 3000 and 3100 Series switches.

    SVI limitation: When a BFD session is over SVI using virtual port-channel(vPC) peer-link, the BFD echo function is not supported. You must disable the BFD echo function for all sessions over SVI between vPC peer nodes using no bfd echo at the SVI configuration level.

  • When a Layer 3 link is used for peer-keepalive instead of the mgmt interface, and the CPU queues are congested with control plane traffic, vPC peer-keepalive packets could be dropped. The CPU traffic includes routing protocol, ARP, Glean, and IPMC miss packets. When the peer-keepalive interface is a Layer 3 link instead of a mgmt interface, the vPC peer-keepalive packets are sent to the CPU on a low-priority queue.

    If a Layer 3 link is used for vPC peer-keepalives, configure the following ACL to prioritize the vPC peer-keepalive: 

    ip access-list copp-system-acl-routingproto2
30 permit udp any any eq 3200

    Here, 3200 is the default UDP port for keepalive packets. This ACL must match the configured UDP port in case the default port is changed.

  • VPC is not supported on the Cisco Nexus 34180YC platform.

Verifying the vPC Configuration

Use the following commands to display vPC configuration information:

Command

Purpose
switch# show feature

Displays whether vPC is enabled or not.
switch# show port-channel capacity

Displays how many EtherChannels are configured and how many are still available on the switch.
switch# show running-config vpc

Displays running configuration information for vPCs.

switch# show vpc brief

Displays brief information on the vPCs.

switch# show vpc consistency-parameters

Displays the status of those parameters that must be consistent across all vPC interfaces.

switch# show vpc peer-keepalive

Displays information on the peer-keepalive messages.
switch# show vpc role

Displays the peer status, the role of the local switch, the vPC system MAC address and system priority, and the MAC address and priority for the local vPC switch.

switch# show vpc statistics

Displays statistics on the vPCs.

Note

 

This command displays the vPC statistics only for the vPC peer device that you are working on.

For information about the switch output, see the Command Reference for your Cisco Nexus Series switch.

Viewing the Graceful Type-1 Check Status

This example shows how to display the current status of the graceful Type-1 consistency check: 

switch# show vpc brief
Legend:
                (*) - local vPC is down, forwarding via vPC peer-link

vPC domain id                   : 10
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       : 34
Peer Gateway                    : Disabled
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)

vPC Peer-link status
---------------------------------------------------------------------
id   Port   Status Active vlans
--   ----   ------ --------------------------------------------------
1    Po1    up     1

Viewing a Global Type-1 Inconsistency

When a global Type-1 inconsistency occurs, the vPCs on the secondary switch are brought down. The following example shows this type of inconsistency when there is a spanning-tree mode mismatch.

The example shows how to display the status of the suspended vPC VLANs on the secondary switch:

switch(config)# show vpc
Legend:
                (*) - local vPC is down, forwarding via vPC peer-link

vPC domain id                   : 10
Peer status                     : peer adjacency formed ok
vPC keep-alive status           : peer is alive
Configuration consistency status: failed
Per-vlan consistency status     : success
Configuration consistency reason: vPC type-1 configuration incompatible - STP 
                                  Mode inconsistent
Type-2 consistency status       : success
vPC role                        : secondary
Number of vPCs configured       : 2
Peer Gateway                    : Disabled
Dual-active excluded VLANs      : -
Graceful Consistency Check      : Enabled

vPC Peer-link status
---------------------------------------------------------------------
id   Port   Status Active vlans
--   ----   ------ --------------------------------------------------
1    Po1    up     1-10

vPC status
----------------------------------------------------------------------------
id     Port        Status Consistency Reason                     Active vlans
------ ----------- ------ ----------- -------------------------- -----------
20     Po20        down*  failed      Global compat check failed -
30     Po30        down*  failed      Global compat check failed -

The example shows how to display the inconsistent status ( the VLANs on the primary vPC are not suspended) on the primary switch: 

switch(config)# show vpc
Legend:
                (*) - local vPC is down, forwarding via vPC peer-link

vPC domain id                   : 10
Peer status                     : peer adjacency formed ok
vPC keep-alive status           : peer is alive
Configuration consistency status: failed
Per-vlan consistency status     : success
Configuration consistency reason: vPC type-1 configuration incompatible - STP Mo
de inconsistent
Type-2 consistency status       : success
vPC role                        : primary
Number of vPCs configured       : 2
Peer Gateway                    : Disabled
Dual-active excluded VLANs      : -
Graceful Consistency Check      : Enabled

vPC Peer-link status
---------------------------------------------------------------------
id   Port   Status Active vlans
--   ----   ------ --------------------------------------------------
1    Po1    up     1-10

vPC status
----------------------------------------------------------------------------
id     Port        Status Consistency Reason                     Active vlans
------ ----------- ------ ----------- -------------------------- -----------
20     Po20        up     failed      Global compat check failed 1-10
30     Po30        up     failed      Global compat check failed 1-10

Viewing an Interface-Specific Type-1 Inconsistency

When an interface-specific Type-1 inconsistency occurs, the vPC port on the secondary switch is brought down while the primary switch vPC ports remain up.The following example shows this type of inconsistency when there is a switchport mode mismatch.

This example shows how to display the status of the suspended vPC VLAN on the secondary switch: 

switch(config-if)# show vpc brief
Legend:
                (*) - local vPC is down, forwarding via vPC peer-link

vPC domain id                   : 10
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       : 2
Peer Gateway                    : Disabled
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)

vPC Peer-link status
---------------------------------------------------------------------
id   Port   Status Active vlans
--   ----   ------ --------------------------------------------------
1    Po1    up     1

vPC status
----------------------------------------------------------------------------
id     Port        Status Consistency Reason                     Active vlans
------ ----------- ------ ----------- -------------------------- -----------
20     Po20        up     success     success                    1
30     Po30        down*  failed      Compatibility check failed -
                                       for port mode

This example shows how to display the inconsistent status (the VLANs on the primary vPC are not suspended) on the primary switch: 

switch(config-if)# show vpc brief
Legend:
                (*) - local vPC is down, forwarding via vPC peer-link

vPC domain id                   : 10
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       : 2
Peer Gateway                    : Disabled
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)

vPC Peer-link status
---------------------------------------------------------------------
id   Port   Status Active vlans
--   ----   ------ --------------------------------------------------
1    Po1    up     1

vPC status
----------------------------------------------------------------------------
id     Port        Status Consistency Reason                     Active vlans
------ ----------- ------ ----------- -------------------------- -----------
20     Po20        up     success     success                    1
30     Po30        up     failed      Compatibility check failed 1
                                       for port mode

Viewing a Per-VLAN Consistency Status

To view the per-VLAN consistency or inconsistency status, enter the show vpc consistency-parameters vlans command.

Example

This example shows how to display the consistent status of the VLANs on the primary and the secondary switches. 

switch(config-if)# show vpc brief
Legend:
                (*) - local vPC is down, forwarding via vPC peer-link

vPC domain id                   : 10
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       : 2
Peer Gateway                    : Disabled
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)

vPC Peer-link status
---------------------------------------------------------------------
id   Port   Status Active vlans
--   ----   ------ --------------------------------------------------
1    Po1    up     1-10

vPC status
----------------------------------------------------------------------------
id     Port        Status Consistency Reason                     Active vlans
------ ----------- ------ ----------- -------------------------- -----------
20     Po20        up     success     success                    1-10
30     Po30        up     success     success                    1-10

Entering no spanning-tree vlan 5 command triggers the inconsistency on the primary and secondary VLANs: 

switch(config)# no spanning-tree vlan 5

This example shows how to display the per-VLAN consistency status as Failed on the secondary switch: 

switch(config)# show vpc brief
Legend:
                (*) - local vPC is down, forwarding via vPC peer-link

vPC domain id                   : 10
Peer status                     : peer adjacency formed ok
vPC keep-alive status           : peer is alive
Configuration consistency status: success
Per-vlan consistency status     : failed
Type-2 consistency status       : success
vPC role                        : secondary
Number of vPCs configured       : 2
Peer Gateway                    : Disabled
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)

vPC Peer-link status
---------------------------------------------------------------------
id   Port   Status Active vlans
--   ----   ------ --------------------------------------------------
1    Po1    up     1-4,6-10

vPC status
----------------------------------------------------------------------------
id     Port        Status Consistency Reason                     Active vlans
------ ----------- ------ ----------- -------------------------- -----------
20     Po20        up     success     success                    1-4,6-10
30     Po30        up     success     success                    1-4,6-10

This example shows how to display the per-VLAN consistency status as Failed on the primary switch: 

switch(config)# show vpc brief
Legend:
                (*) - local vPC is down, forwarding via vPC peer-link

vPC domain id                   : 10
Peer status                     : peer adjacency formed ok
vPC keep-alive status           : peer is alive
Configuration consistency status: success
Per-vlan consistency status     : failed
Type-2 consistency status       : success
vPC role                        : primary
Number of vPCs configured       : 2
Peer Gateway                    : Disabled
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)

vPC Peer-link status
---------------------------------------------------------------------
id   Port   Status Active vlans
--   ----   ------ --------------------------------------------------
1    Po1    up     1-4,6-10

vPC status
----------------------------------------------------------------------------
id     Port        Status Consistency Reason                     Active vlans
------ ----------- ------ ----------- -------------------------- -----------
20     Po20        up     success     success                    1-4,6-10
30     Po30        up     success     success                    1-4,6-10

This example shows the inconsistency as STP Disabled: 

switch(config)# show vpc consistency-parameters vlans

Name                        Type  Reason Code             Pass Vlans

-------------               ----  ---------------------- -----------------------
STP Mode                    1     success                0-4095
STP Disabled                1     vPC type-1             0-4,6-4095
                                  configuration
                                  incompatible - STP is
                                  enabled or disabled on
                                   some or all vlans
STP MST Region Name         1     success                0-4095
STP MST Region Revision     1     success                0-4095
STP MST Region Instance to  1     success                0-4095
 VLAN Mapping
STP Loopguard               1     success                0-4095
STP Bridge Assurance        1     success                0-4095
STP Port Type, Edge         1     success                0-4095
BPDUFilter, Edge BPDUGuard
STP MST Simulate PVST       1     success                0-4095
Pass Vlans                  -                            0-4,6-4095

vPC Default Settings

The following table lists the default settings for vPC parameters.

Table 1. Default vPC Parameters

Parameters

Default

vPC system priority

32667

vPC peer-keepalive message

Disabled

vPC peer-keepalive interval

1 second

vPC peer-keepalive timeout

5 seconds

vPC peer-keepalive UDP port

3200

Configuring vPCs

Enabling vPCs

You must enable the vPC feature before you can configure and use vPCs.

SUMMARY STEPS

  1. switch# configure terminal
  2. switch(config)# feature vpc
  3. (Optional) switch# show feature
  4. (Optional) switch# copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

switch# configure terminal

Enters global configuration mode.

Step 2

switch(config)# feature vpc

Enables vPCs on the switch.

Step 3

(Optional) switch# show feature

(Optional)

Displays which features are enabled on the switch.

Step 4

(Optional) switch# copy running-config startup-config

(Optional)

Copies the running configuration to the startup configuration.

Example

This example shows how to enable the vPC feature: 

switch# configure terminal
switch(config)# feature vpc

Disabling vPCs

You can disable the vPC feature.


Note

When you disable the vPC feature, the Cisco Nexus device clears all the vPC configurations.

SUMMARY STEPS

  1. switch# configure terminal
  2. switch(config)# no feature vpc
  3. (Optional) switch# show feature
  4. (Optional) switch# copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

switch# configure terminal

Enters global configuration mode.

Step 2

switch(config)# no feature vpc

Disables vPCs on the switch.

Step 3

(Optional) switch# show feature

(Optional)

Displays which features are enabled on the switch.

Step 4

(Optional) switch# copy running-config startup-config

(Optional)

Copies the running configuration to the startup configuration.

Example

This example shows how to disable the vPC feature: 

switch# configure terminal
switch(config)# no feature vpc

Creating a vPC Domain

You must create identical vPC domain IDs on both the vPC peer devices. This domain ID is used to automatically form the vPC system MAC address.

Before you begin

Ensure that you have enabled the vPC feature.

You must configure both switches on either side of the vPC peer link.

SUMMARY STEPS

  1. switch# configure terminal
  2. switch(config)# vpc domain domain-id
  3. (Optional) switch# show vpc brief
  4. (Optional) switch# copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

switch# configure terminal

Enters global configuration mode.

Step 2

switch(config)# vpc domain domain-id

Creates a vPC domain on the switch, and enters the vpc-domain configuration mode. There is no default domain-id ; the range is from 1 to 1000.

Note

 

You can also use the vpc domain command to enter the vpc-domain configuration mode for an existing vPC domain.

Step 3

(Optional) switch# show vpc brief

(Optional)

Displays brief information about each vPC domain.

Step 4

(Optional) switch# copy running-config startup-config

(Optional)

Copies the running configuration to the startup configuration.

Example

This example shows how to create a vPC domain: 

switch# configure terminal
switch(config)# vpc domain 5

Configuring a vPC Keepalive Link and Messages

You can configure the destination IP for the peer-keepalive link that carries the keepalive messages. Optionally, you can configure other parameters for the keepalive messages.

The Cisco NX-OS software uses the peer-keepalive link between the vPC peers to transmit periodic, configurable keepalive messages. You must have Layer 3 connectivity between the peer devices to transmit these messages. The system cannot bring up the vPC peer link unless the peer-keepalive link is already up and running.

Ensure that both the source and destination IP addresses used for the peer-keepalive message are unique in your network and these IP addresses are reachable from the Virtual Routing and Forwarding (VRF) instance associated with the vPC peer-keepalive link.


Note

We recommend that you configure a separate VRF instance and put a Layer 3 port from each vPC peer switch into that VRF instance for the vPC peer-keepalive link. Do not use the peer link itself to send vPC peer-keepalive messages.

Before you begin

Ensure that you have enabled the vPC feature.

You must configure the vPC peer-keepalive link before the system can form the vPC peer link.

You must configure both switches on either side of the vPC peer link.

SUMMARY STEPS

  1. switch# configure terminal
  2. switch(config)# vpc domain domain-id
  3. switch(config-vpc-domain)# peer-keepalive destination ipaddress [hold-timeout secs | interval msecs {timeout secs} | precedence {prec-value | network | internet | critical | flash-override | flash | immediate priority | routine} | tos {tos-value | max-reliability | max-throughput | min-delay | min-monetary-cost | normal} | tos-byte tos-byte-value} | source ipaddress | vrf {name | management vpc-keepalive}]
  4. (Optional) switch(config-vpc-domain)# vpc peer-keepalive destination ipaddress source ipaddress
  5. (Optional) switch# show vpc peer-keepalive
  6. (Optional) switch# copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

switch# configure terminal

Enters global configuration mode.

Step 2

switch(config)# vpc domain domain-id

Creates a vPC domain on the switch if it does not already exist, and enters the vpc-domain configuration mode.

Step 3

switch(config-vpc-domain)# peer-keepalive destination ipaddress [hold-timeout secs | interval msecs {timeout secs} | precedence {prec-value | network | internet | critical | flash-override | flash | immediate priority | routine} | tos {tos-value | max-reliability | max-throughput | min-delay | min-monetary-cost | normal} | tos-byte tos-byte-value} | source ipaddress | vrf {name | management vpc-keepalive}]

Configures the IPv4 address for the remote end of the vPC peer-keepalive link.

Note

 

The system does not form the vPC peer link until you configure a vPC peer-keepalive link.

The management ports and VRF are the defaults.

Step 4

(Optional) switch(config-vpc-domain)# vpc peer-keepalive destination ipaddress source ipaddress

(Optional)

Configures a separate VRF instance and puts a Layer 3 port from each vPC peer device into that VRF for the vPC peer-keepalive link.

Step 5

(Optional) switch# show vpc peer-keepalive

(Optional)

Displays information about the configuration for the keepalive messages.

Step 6

(Optional) switch# copy running-config startup-config

(Optional)

Copies the running configuration to the startup configuration.

Example

This example shows how to configure the destination IP address for the vPC-peer-keepalive link: 


switch# configure terminal
switch(config)# vpc domain 5
switch(config-vpc-domain)# peer-keepalive destination 10.10.10.42

This example shows how to set up the peer keepalive link connection between the primary and secondary vPC device:


switch(config)# vpc domain 100
switch(config-vpc-domain)# peer-keepalive destination 192.168.2.2 source 192.168.2.1
Note:--------:: Management VRF will be used as the default VRF ::--------
switch(config-vpc-domain)#

This example shows how to create a separate VRF named vpc_keepalive for the vPC keepalive link and how to verify the new VRF:


vrf context vpc_keepalive
interface Ethernet1/31
  switchport access vlan 123
interface Vlan123
  vrf member vpc_keepalive
  ip address 123.1.1.2/30
  no shutdown
vpc domain 1
  peer-keepalive destination 123.1.1.1 source 123.1.1.2 vrf 
vpc_keepalive

L3-NEXUS-2# show vpc peer-keepalive 

vPC keep-alive status           : peer is alive                 
--Peer is alive for             : (154477) seconds, (908) msec
--Send status                   : Success 
--Last send at                  : 2011.01.14 19:02:50 100 ms
--Sent on interface             : Vlan123
--Receive status                : Success
--Last receive at               : 2011.01.14 19:02:50 103 ms
--Received on interface         : Vlan123
--Last update from peer         : (0) seconds, (524) msec

vPC Keep-alive parameters
--Destination                   : 123.1.1.1
--Keepalive interval            : 1000 msec
--Keepalive timeout             : 5 seconds
--Keepalive hold timeout        : 3 seconds
--Keepalive vrf                 : vpc_keepalive
--Keepalive udp port            : 3200
--Keepalive tos                 : 192

The services provided by the switch , such as ping, ssh, telnet, 
radius, are VRF aware. The VRF name need to be configured or 
specified in order for the correct routing table to be used.
L3-NEXUS-2# ping 123.1.1.1 vrf vpc_keepalive 
PING 123.1.1.1 (123.1.1.1): 56 data bytes
64 bytes from 123.1.1.1: icmp_seq=0 ttl=254 time=3.234 ms
64 bytes from 123.1.1.1: icmp_seq=1 ttl=254 time=4.931 ms
64 bytes from 123.1.1.1: icmp_seq=2 ttl=254 time=4.965 ms
64 bytes from 123.1.1.1: icmp_seq=3 ttl=254 time=4.971 ms
64 bytes from 123.1.1.1: icmp_seq=4 ttl=254 time=4.915 ms

--- 123.1.1.1 ping statistics ---
5 packets transmitted, 5 packets received, 0.00% packet loss
round-trip min/avg/max = 3.234/4.603/4.971 ms

Creating a vPC Peer Link

You can create a vPC peer link by designating the EtherChannel that you want on each switch as the peer link for the specified vPC domain. We recommend that you configure the EtherChannels that you are designating as the vPC peer link in trunk mode and that you use two ports on separate modules on each vPC peer switch for redundancy.

Before you begin

Ensure that you have enabled the vPC feature.

You must configure both switches on either side of the vPC peer link

SUMMARY STEPS

  1. switch# configure terminal
  2. switch(config)# interface port-channel channel-number
  3. switch(config-if)# vpc peer-link
  4. (Optional) switch# show vpc brief
  5. (Optional) switch# copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

switch# configure terminal

Enters global configuration mode.

Step 2

switch(config)# interface port-channel channel-number

Selects the EtherChannel that you want to use as the vPC peer link for this switch, and enters the interface configuration mode.

Step 3

switch(config-if)# vpc peer-link

Configures the selected EtherChannel as the vPC peer link, and enters the vpc-domain configuration mode.

Step 4

(Optional) switch# show vpc brief

(Optional)

Displays information about each vPC, including information about the vPC peer link.

Step 5

(Optional) switch# copy running-config startup-config

(Optional)

Copies the running configuration to the startup configuration.

Example

This example shows how to configure a vPC peer link: 

switch# configure terminal
switch(config)# interface port-channel 20
switch(config-if)# vpc peer-link

Checking the Configuration Compatibility

After you have configured the vPC peer link on both vPC peer switches, check that the configurations are consistent on all vPC interfaces.

The following QoS parameters support Type 2 consistency checks

  • Network QoS—MTU and Pause

  • Input Queuing —Bandwidth and Absolute Priority

  • Output Queuing—Bandwidth and Absolute Priority

In the case of a Type 2 mismatch, the vPC is not suspended. Type 1 mismatches suspend the vPC.

SUMMARY STEPS

  1. switch# show vpc consistency-parameters{global|interface port-channelchannel-number}

DETAILED STEPS

Command or Action Purpose

switch# show vpc consistency-parameters{global|interface port-channelchannel-number}

Displays the status of those parameters that must be consistent across all vPC interfaces.

Example

This example shows how to check that the required configurations are compatible across all the vPC interfaces: 

switch# show vpc consistency-parameters global
Legend:
         Type 1 : vPC will be suspended in case of mismatch
Name                        Type  Local Value            Peer Value 

------------- ----  ---------------------- -----------------------
QoS                         2     ([], [], [], [], [],   ([], [], [], [], [],
                                   [])                    []) 

Network QoS (MTU)           2     (1538, 0, 0, 0, 0, 0)  (1538, 0, 0, 0, 0, 0)
Network Qos (Pause)         2     (F, F, F, F, F, F)     (1538, 0, 0, 0, 0, 0)
Input Queuing (Bandwidth)   2     (100, 0, 0, 0, 0, 0)   (100, 0, 0, 0, 0, 0)
Input Queuing (Absolute     2     (F, F, F, F, F, F)     (100, 0, 0, 0, 0, 0)
Priority) 
Output Queuing (Bandwidth)  2     (100, 0, 0, 0, 0, 0)   (100, 0, 0, 0, 0, 0)
Output Queuing (Absolute    2     (F, F, F, F, F, F)     (100, 0, 0, 0, 0, 0)
Priority) 
STP Mode                    1     Rapid-PVST             Rapid-PVST 
STP Disabled                1     None                   None 
STP MST Region Name         1     ""                     "" 
STP MST Region Revision     1     0                      0 
STP MST Region Instance to  1 
  VLAN Mapping 

STP Loopguard               1     Disabled               Disabled 
STP Bridge Assurance        1     Enabled                Enabled 
STP Port Type, Edge         1     Normal, Disabled,      Normal, Disabled,
BPDUFilter, Edge BPDUGuard        Disabled               Disabled 
STP MST Simulate PVST       1     Enabled                Enabled 
Allowed VLANs               -     1,624                  1 
Local suspended VLANs       -     624                    - 
switch#

Enabling vPC Auto-Recovery

SUMMARY STEPS

  1. switch# configure terminal
  2. switch(config)# vpc domain domain-id
  3. switch(config-vpc-domain)# auto-recovery reload-delay delay

DETAILED STEPS

  Command or Action Purpose

Step 1

switch# configure terminal

Enters global configuration mode.

Step 2

switch(config)# vpc domain domain-id

Enters vpc-domain configuration mode for an existing vPC domain.

Step 3

switch(config-vpc-domain)# auto-recovery reload-delay delay

Enables the auto-recovery feature and sets the reload delay period. The default is disabled.

Example

This example shows how to enable the auto-recovery feature in vPC domain 10 and set the delay period for 240 seconds: 

switch(config)# vpc domain 10
switch(config-vpc-domain)# auto-recovery reload-delay 240
Warning:
 Enables restoring of vPCs in a peer-detached state after reload, will wait for 240 seconds (by default) to determine if peer is un-reachable

This example shows how to view the status of the auto-recovery feature in vPC domain 10: 

switch(config-vpc-domain)# show running-config vpc
!Command: show running-config vpc
!Time: Tue Dec  7 02:38:44 2010


version 5.0(3)U2(1)
feature vpc
vpc domain 10
  peer-keepalive destination 10.193.51.170
  auto-recovery

Configuring the Restore Time Delay

You can configure a restore timer that delays the vPC from coming back up until after the peer adjacency forms and the VLAN interfaces are back up. This feature avoids packet drops if the routing tables fail to converge before the vPC is once again passing traffic.

Before you begin

Ensure that you have enabled the vPC feature.

You must configure both switches on either side of the vPC peer link with the following procedures.

SUMMARY STEPS

  1. switch# configure terminal
  2. switch(config)# vpc domain domain-id
  3. switch(config-vpc-domain)# delay restore time
  4. (Optional) switch# copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

switch# configure terminal

Enters global configuration mode.

Step 2

switch(config)# vpc domain domain-id

Creates a vPC domain on the switch if it does not already exist, and enters vpc-domain configuration mode.

Step 3

switch(config-vpc-domain)# delay restore time

Configures the time delay before the vPC is restored.

The restore time is the number of seconds to delay bringing up the restored vPC peer device. The range is from 1 to 3600. The default is 30 seconds.

Step 4

(Optional) switch# copy running-config startup-config

(Optional)

Copies the running configuration to the startup configuration.

Example

This example shows how to configure the delay reload time for a vPC link: 

switch(config)# vpc domain 1
switch(config-vpc-domain)# delay restore 10
switch(config-vpc-domain)#

Configuring Delay Restore on an Orphan Port

You can configure delay restore orphan-port command on Cisco Nexus 3000 Series switches to configure a restore timer that delays the bringing up of restored device's orphan port.

SUMMARY STEPS

  1. configure terminal
  2. switch(config) # vpc domain <domain>
  3. switch(config) # peer-switch
  4. switch(config) # show vpc peer-keepalive
  5. switch(config) # delay restore { time }
  6. switch(config) # peer-gateway
  7. switch(config) # delay restore orphan-port

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Enters global configuration mode.

Step 2

switch(config) # vpc domain <domain>

Configure the VPC domain number.

Step 3

switch(config) # peer-switch

Define the peer switch.

Step 4

switch(config) # show vpc peer-keepalive

Displays information about the peer keepalive messages

Step 5

switch(config) # delay restore { time }

Number of seconds to delay bringing up the restored vPC peer device. The range is from 1 to 3600.

Step 6

switch(config) # peer-gateway

To enable Layer 3 forwarding for packets destined to the gateway MAC address of the virtual Port Channel (vPC), use the peer-gateway command. To disable Layer 3 forwarding packets, use the no form of this command.

.

Step 7

switch(config) # delay restore orphan-port

Number of seconds to delay bringing up the restored device's orphan port

Configuring the Suspension of Orphan Ports

When a device that is not vPC-capable connects to each peer, the connected ports are known as orphan ports because they are not members of a vPC. You can explicitly declare phyiscal interfaces as orphan ports to be suspended (shut down) by the secondary peer when it suspends its vPC ports in response to a peer link or peer-keepalive failure. The orphan ports are restored when the vPC is restored.


Note

You can configure vPC orphan port suspension only on physical ports, not on port channel member ports.

Before you begin

Ensure that you have enabled the vPC feature.

Ensure that you are in the correct VDC (or use the switchto vdc command).

SUMMARY STEPS

  1. configure terminal
  2. show vpc orphan-ports
  3. interfacetype slot/port
  4. vpc orphan-ports suspend
  5. exit
  6. copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Example:

switch# configure terminal
switch(config)#

Enters global configuration mode.

Step 2

show vpc orphan-ports

Example:

switch(config)# show vpc orphan-ports
switch(config-vpc-domain)#

(Optional) Displays a list of the orphan ports.

Step 3

interfacetype slot/port

Example:

switch(config)# interface ethernet 3/1
switch(config-if)#

Specifies an interface to configure, and enters interface configuration mode.

Step 4

vpc orphan-ports suspend

Example:


switch(config-if)# vpc orphan-ports suspend

Configures the selected interface as a vPC orphan port to be suspended by the secondary peer in case of vPC failure.

Step 5

exit

Example:


switch(config-if)# exit

Exits the interface configuration mode.

Step 6

copy running-config startup-config

Example:

switch# copy running-config startup-config

(Optional) Copies the running configuration to the startup configuration.

Example

This example shows how to configure an interface as a vPC orphan port to be suspended by the secondary peer in case of vPC failure: 


switch# configure terminal
switch(config)# interface ethernet 3/1
switch(config-if)# vpc orphan-ports suspend
switch(config-if)#

Excluding VLAN Interfaces from Shutting Down a vPC Peer Link Fails

When a vPC peer-link is lost, the vPC secondary switch suspends its vPC member ports and its switch virtual interface (SVI) interfaces. All Layer 3 forwarding is disabled for all VLANs on the vPC secondary switch. You can exclude specific SVI interfaces so that they are not suspended.

Before you begin

Ensure that the VLAN interfaces have been configured.

SUMMARY STEPS

  1. switch# configure terminal
  2. switch(config)# vpc domain domain-id
  3. switch(config-vpc-domain))# dual-active exclude interface-vlan range

DETAILED STEPS

  Command or Action Purpose

Step 1

switch# configure terminal

Enters global configuration mode.

Step 2

switch(config)# vpc domain domain-id

Creates a vPC domain on the switch if it does not already exist, and enters vpc-domain configuration mode.

Step 3

switch(config-vpc-domain))# dual-active exclude interface-vlan range

Specifies the VLAN interfaces that should remain up when a vPC peer-link is lost.

range—Range of VLAN interfaces that you want to exclude from shutting down. The range is from 1 to 4094.

Example

This example shows how to keep the interfaces on VLAN 10 up on the vPC peer switch if a peer link fails: 


switch# configure terminal
switch(config)# vpc domain 5
switch(config-vpc-domain)# dual-active exclude interface-vlan 10
switch(config-vpc-domain)#

Configuring the VRF Name

The switch services, such as ping, ssh, telnet, radius, are VRF aware. You must configure the VRF name in order for the correct routing table to be used.

You can specify the VRF name.

SUMMARY STEPS

  1. switch# ping ipaddress vrf vrf-name

DETAILED STEPS

Command or Action Purpose

switch# ping ipaddress vrf vrf-name

Specifies the virtual routing and forwarding (VRF) name to use. The VRF name is case sensitive and can be a maximum of 32 characters..

Example

This example shows how to specifiy the VRF named vpc_keepalive:

switch# ping 123.1.1.1 vrf vpc_keepalive 
PING 123.1.1.1 (123.1.1.1): 56 data bytes
64 bytes from 123.1.1.1: icmp_seq=0 ttl=254 time=3.234 ms
64 bytes from 123.1.1.1: icmp_seq=1 ttl=254 time=4.931 ms
64 bytes from 123.1.1.1: icmp_seq=2 ttl=254 time=4.965 ms
64 bytes from 123.1.1.1: icmp_seq=3 ttl=254 time=4.971 ms
64 bytes from 123.1.1.1: icmp_seq=4 ttl=254 time=4.915 ms

--- 123.1.1.1 ping statistics ---
5 packets transmitted, 5 packets received, 0.00% packet loss
round-trip min/avg/max = 3.234/4.603/4.971 ms

Moving Other Port Channels into a vPC

Before you begin

Ensure that you have enabled the vPC feature.

You must configure both switches on either side of the vPC peer link with the following procedure.

SUMMARY STEPS

  1. switch# configure terminal
  2. switch(config)# interface port-channel channel-number
  3. switch(config-if)# vpc number
  4. (Optional) switch# show vpc brief
  5. (Optional) switch# copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

switch# configure terminal

Enters global configuration mode.

Step 2

switch(config)# interface port-channel channel-number

Selects the port channel that you want to put into the vPC to connect to the downstream switch, and enters interface configuration mode.

Note

 

A vPC can be configured on a normal port channel (physical vPC topology) and on a port channel host interface (host interface vPC topology)

Step 3

switch(config-if)# vpc number

Configures the selected port channel into the vPC to connect to the downstream switch. The range is from 1 to 4096.

The vPC number that you assign to the port channel that connects to the downstream switch from the vPC peer switch must be identical on both vPC peer switches.

Step 4

(Optional) switch# show vpc brief

(Optional)

Displays information about each vPC.

Step 5

(Optional) switch# copy running-config startup-config

(Optional)

Copies the running configuration to the startup configuration.

Example

This example shows how to configure a port channel that will connect to the downstream device: 

switch# configure terminal
switch(config)# interface port-channel 20
switch(config-if)# vpc 5

Manually Configuring a vPC Domain MAC Address


Note

Configuring the system address is an optional configuration step.

Before you begin

Ensure that you have enabled the vPC feature.

You must configure both switches on either side of the vPC peer link.

SUMMARY STEPS

  1. switch# configure terminal
  2. switch(config)# vpc domain domain-id
  3. switch(config-vpc-domain)# system-mac mac-address
  4. (Optional) switch# show vpc role
  5. (Optional) switch# copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

switch# configure terminal

Enters global configuration mode.

Step 2

switch(config)# vpc domain domain-id

Selects an existing vPC domain on the switch, or creates a new vPC domain, and enters the vpc-domain configuration mode. There is no default domain-id ; the range is from 1 to 1000.

Step 3

switch(config-vpc-domain)# system-mac mac-address

Enters the MAC address that you want for the specified vPC domain in the following format: aaaa.bbbb.cccc.

Step 4

(Optional) switch# show vpc role

(Optional)

Displays the vPC system MAC address.

Step 5

(Optional) switch# copy running-config startup-config

(Optional)

Copies the running configuration to the startup configuration.

Example

This example shows how to configure a vPC domain MAC address: 

switch# configure terminal
switch(config)# vpc domain 5
switch(config-if)# system-mac 23fb.4ab5.4c4e

Manually Configuring the System Priority

When you create a vPC domain, the system automatically creates a vPC system priority. However, you can also manually configure a system priority for the vPC domain.

Before you begin

Ensure that you have enabled the vPC feature.

You must configure both switches on either side of the vPC peer link.

SUMMARY STEPS

  1. switch# configure terminal
  2. switch(config)# vpc domain domain-id
  3. switch(config-vpc-domain)# system-priority priority
  4. (Optional) switch# show vpc brief
  5. (Optional) switch# copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

switch# configure terminal

Enters global configuration mode.

Step 2

switch(config)# vpc domain domain-id

Selects an existing vPC domain on the switch, or creates a new vPC domain, and enters the vpc-domain configuration mode. There is no default domain-id ; the range is from 1 to 1000.

Step 3

switch(config-vpc-domain)# system-priority priority

Enters the system priority that you want for the specified vPC domain. The range of values is from 1 to 65535. The default value is 32667.

Step 4

(Optional) switch# show vpc brief

(Optional)

Displays information about each vPC, including information about the vPC peer link.

Step 5

(Optional) switch# copy running-config startup-config

(Optional)

Copies the running configuration to the startup configuration.

Example

This example shows how to configure a vPC peer link: 

switch# configure terminal
switch(config)# vpc domain 5
switch(config-if)# system-priority 4000

Manually Configuring a vPC Peer Switch Role

By default, the Cisco NX-OS software elects a primary and secondary vPC peer switch after you configure the vPC domain and both sides of the vPC peer link. However, you may want to elect a specific vPC peer switch as the primary switch for the vPC. Then, you would manually configure the role value for the vPC peer switch that you want as the primary switch to be lower than the other vPC peer switch.

vPC does not support role preemption. If the primary vPC peer switch fails, the secondary vPC peer switch takes over to become operationally the vPC primary switch. However, the original operational roles are not restored when the formerly primary vPC comes up again.

Before you begin

Ensure that you have enabled the vPC feature.

You must configure both switches on either side of the vPC peer link.

SUMMARY STEPS

  1. switch# configure terminal
  2. switch(config)# vpc domain domain-id
  3. switch(config-vpc-domain)# role priority priority
  4. (Optional) switch# show vpc brief
  5. (Optional) switch# copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

switch# configure terminal

Enters global configuration mode.

Step 2

switch(config)# vpc domain domain-id

Selects an existing vPC domain on the switch, or creates a new vPC domain, and enters the vpc-domain configuration mode. There is no default domain-id ; the range is from 1 to 1000.

Step 3

switch(config-vpc-domain)# role priority priority

Enters the role priority that you want for the vPC system priority. The range of values is from 1 to 65535. The default value is 32667.

Step 4

(Optional) switch# show vpc brief

(Optional)

Displays information about each vPC, including information about the vPC peer link.

Step 5

(Optional) switch# copy running-config startup-config

(Optional)

Copies the running configuration to the startup configuration.

Example

This example shows how to configure a vPC peer link: 

switch# configure terminal
switch(config)# vpc domain 5
switch(config-if)# role priority 4000

Configuring Layer 3 over vPC

Before you begin

Ensure that the peer-gateway feature is enabled and it is configured on both the peers and both the peers run an image that supports Layer 3 over vPC. If you enter the layer3 peer-router command without enabling the peer-gateway feature, a syslog message is displayed recommending you to enable the peer-gateway feature.

Ensure that the vPC Peer-Link is up.

SUMMARY STEPS

  1. switch# configure terminal
  2. switch(config)# vpc domain domain-id
  3. switch(config-vpc-domain)#layer3 peer-router
  4. switch(config-vpc-domain)# exit
  5. (Optional) switch#show vpc brief
  6. (Optional) switch#copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

switch# configure terminal

Example:

switch# configure terminal
switch(config)#

Enters global configuration mode.

Step 2

switch(config)# vpc domain domain-id

Example:

switch(config)# vpc domain 5
switch(config-vpc-domain)#

Creates a vPC domain if it does not already exist, and enters the vpc-domain configuration mode. There is no default; the range is from <1 to 1000>.

Step 3

switch(config-vpc-domain)#layer3 peer-router

Enables the Layer 3 device to form peering adjacency with both the peers.

Note

 

Configure this command in both the peers. If you configure this command only on one of the peers or you disable it on one peer, the operational state of layer 3 peer-router gets disabled. You get a notification when there is a change in the operational state.

Step 4

switch(config-vpc-domain)# exit

Exits the vpc-domain configuration mode.

Step 5

(Optional) switch#show vpc brief

(Optional)

Displays brief information about each vPC domain.

Step 6

(Optional) switch#copy running-config startup-config

(Optional)

Copies the running configuration to the startup configuration.

Example

The following example shows how to configure Layer 3 over vPC feature:

switch# configure terminal
switch(config)# vpc domain 5
switch(config-vpc-domain)# layer3 peer-router

switch(config-vpc-domain)# exit

switch(config)#

This example shows how to verify if the Layer 3 over vPC feature is configured. The Operational Layer3 Peer is enabled or disabled depending up on how the operational state of Layer 3 over vPC is configured. 

switch# show vpc brief

vPC domain id : 5
Peer status : peer adjacency formed ok
vPC keep-alive status : peer is alive
Configuration consistency status : success
Per-vlan consistency status : failed
Type-2 consistency status : success
vPC role : secondary
Number of vPCs configured : 2
Peer Gateway : Enabled
Peer gateway excluded VLANs : -
Dual-active excluded VLANs : -
Graceful Consistency Check : Enabled
Auto-recovery status : Enabled (timeout = 240 seconds)
Operational Layer3 Peer : Enabled