NVIDIA User Experience - NVUE

NVUE is an object-oriented, schema driven model of a complete Cumulus Linux system (hardware and software) providing a robust API that allows for multiple interfaces to both view (show) and configure (set and unset) any element within a system running the NVUE software.

The NVUE object model definition uses the OpenAPI specification (OAS). Similar to YANG (RFC 6020 and RFC 7950), OAS is a data definition, manipulation, and modeling language (DML) that lets you build model-driven interfaces for both humans and machines. Although the computer networking and telecommunications industry commonly uses YANG (standardized by IETF) as a DML, the adoption of OpenAPI is broader, spanning cloud to compute to storage to IoT and even social media. The OpenAPI Initiative (OAI) consortium leads OpenAPI standardization, a chartered project under the Linux Foundation.

The OAS schema forms the management plane model with which you configure, monitor, and manage the Cumulus Linux switch. The v3.0.2 version of OAS defines the NVUE data model.

Like other systems that use OpenAPI, the NVUE OAS schema defines the endpoints (paths) exposed as RESTful APIs. With these REST APIs, you can perform various create, retrieve, update, delete, and eXecute (CRUDX) operations. The OAS schema also describes the API inputs and outputs (data models).

You can use the NVUE object model in these two ways:

• Through the NVUE REST API, where you run the GET, PATCH, DELETE, and other REST APIs on the NVUE object model endpoints to configure, monitor, and manage the switch. Because of the large user community and maturity of OAS, you can use several popular tools and libraries to create client-side bindings to use the NVUE REST API.
• Through the NVUE CLI, where you configure, monitor and manage the Cumulus Linux network elements. The CLI commands translate to their equivalent REST APIs, which Cumulus Linux then runs on the NVUE object model.

The CLI and the REST API are equivalent in functionality; you can run all management operations from the REST API or the CLI. The NVUE object model drives both the REST API and the CLI management operations. All operations are consistent; for example, the CLI nv show commands reflect any PATCH operation (create) you run through the REST API.

NVUE follows a declarative model, removing context-specific commands and settings. It is structured as a big tree that represents the entire state of a Cumulus Linux instance. At the base of the tree are high level branches representing objects, such as router and interface. Under each of these branches are further branches. As you navigate through the tree, you gain a more specific context. At the leaves of the tree are actual attributes, represented as key-value pairs. The path through the tree is similar to a filesystem path.

NVUE Service

Cumulus Linux installs NVUE by default and enables the NVUE service nvued.

NVUE REST API

To access the NVUE API, run these commands on the switch:

cumulus@switch:~$ sudo ln -s /etc/nginx/sites-{available,enabled}/nvue.conf
cumulus@switch:~$ sudo sed -i 's/listen localhost:8765 ssl;/listen \[::\]:8765 ipv6only=off ssl;/g' /etc/nginx/sites-available/nvue.conf
cumulus@switch:~$ sudo systemctl restart nginx

You can run the cURL commands from the command line. Use the username and password for the switch. For example:

cumulus@switch:~$ curl  -u 'cumulus:CumulusLinux!' --insecure https://127.0.0.1:8765/cue_v1/interface
{
  "eth0": {
    "ip": {
      "address": {
        "192.168.200.12/24": {}
      }
    },
    "link": {
      "mtu": 1500,
      "state": {
        "up": {}
      },
      "stats": {
        "carrier-transitions": 2,
        "in-bytes": 184151,
        "in-drops": 0,
        "in-errors": 0,
        "in-pkts": 2371,
        "out-bytes": 117506,
        "out-drops": 0,
        "out-errors": 0,
        "out-pkts": 762
      }
...

Set a Configuration Change

To make a configuration change with the NVUE API:

1. Create a new revision ID using a POST:

   $ curl -u 'cumulus:cumulus' --insecure -X POST https://127.0.0.1:8765/nvue_v1/revision
   {
     "changeset/cumulus/2021-11-02_16.09.18_5Z1K": {
       "state": "pending",
       "transition": {
         "issue": {},
         "progress": ""
       }
     }
   }
   
   

   To allow the cumulus user access to the NVUE API, you must change the default password for the cumulus user.

2. Record the revision ID. In the above example, the revision ID is "changeset/cumulus/2021-11-02_16.09.18_5Z1K"

3. Make the change using a PATCH and link it to the revision ID:

   $ curl -u 'cumulus:cumulus' -d '{"99.99.99.99/32": {}}' -H 'Content-Type: application/json' --insecure -X PATCH https://127.0.0.1:8765/nvue_v1/interface/lo/ip/address?rev=changeset/cumulus/2021-11-02_16.09.18_5Z1K
   {
     "99.99.99.99/32": {}
   }
   

4. Apply the changes using a PATCH to the revision changeset. You must use the full key value for the revision and replace /​ with %2F​ in the list:

   $ curl -u 'cumulus:cumulus' -d '{"state":"apply"}' -H 'Content-Type:application/json' --insecure -X PATCH https://127.0.0.1:8765/nvue_v1/revision/changeset%2Fcumulus%2F2021-11-02_16.09.18_5Z1K
   {
     "state": "apply",
     "transition": {
       "issue": {},
       "progress": ""
     }
   }
   

5. Review the status of the apply and the configuration:

   cumulus@leaf01:mgmt:~$ curl -u 'cumulus:cumulus' --insecure https://127.0.0.1:8765/nvue_v1/revision/changeset%2Fcumulus%2F2021-11-02_16.09.18_5Z1K
   {
     "state": "applied",
     "transition": {
       "issue": {},
       "progress": ""
     }
   }
   

   $ curl -u 'cumulus:cumulus' --insecure https://127.0.0.1:8765/nvue_v1/interface/lo/ip/address
   {
     "127.0.0.1/8": {},
     "99.99.99.99/32": {},
     "::1/128": {}
   }
   

Unset a Configuration Change

To unset a change, use the null value to the key. For example, to delete vlan100 from a switch, use the following syntax:

$ curl -u 'cumulus:cumulus' -d '{"vlan100":null}' -H 'Content-Type: application/json' --insecure -X PATCH https://127.0.0.1:8765/nvue_v1/interface?rev=changeset/cumulus/2021-11-29_11.46.23_6C7T

When you unset a change, you must still use the PATCH action. The value indicates removal of the entry. The data is {"vlan100":null} with the PATCH action.

Access the NVUE REST API from a Front Panel Port

To access the NVUE REST API from a front panel port (swp) on the switch:

1. Ensure that the nvue.conf file is present in the /etc/nginx/sites-enabled directory.

   Either copy the packaged template file nvue.conf from the /etc/nginx/sites-available directory to the /etc/nginx/sites-enabled directory or create a symbolic link.

2. Edit the nvue.conf file and add the listen directive with the IPv4 or IPv6 address of the swp interface you want to use.

   The default nvue.conf file includes a single listen localhost:8765 ssl; entry. Add an entry for each swp interface with its IP address. Make sure to use an accessible HTTP (TCP) port (subject to any ACL/firewall rules). For information on the NGINX listen directive, see the NGINX documentation.

3. Restart the nginx service:

   cumulus@switch:~$ sudo systemctl reload-or-restart nginx
   

Troubleshoot Configuration Changes

When a configuration change fails, you see an error in the change request.

Configuration Fails Because of a Dependency

If you stage a configuration but it fails because of a dependency, the failure shows the reason. In the following example, the change fails because the BGP router ID is not set:

$ curl -u 'cumulus:cumulus' --insecure https://127.0.0.1:8765/nvue_v1/revision/changeset%2Fcumulus%2F2021-11-02_13.57.25_5Z1H
{
  "state": "invalid",
  "transition": {
    "issue": {
      "0": {
        "code": "config_invalid",
        "data": {
          "location": "router.bgp.enable",
          "reason": "BGP requires router-id to be set globally or in the VRF.\n"
        },
        "message": "Config invalid at router.bgp.enable: BGP requires router-id to be set globally or in the VRF.\n",
        "severity": "error"
      }
    },
    "progress": "Invalid config"
  }
}

The staged configuration is missing router-id:

$ curl -u 'cumulus:cumulus' --insecure https://127.0.0.1:8765/nvue_v1/vrf/default/router/bgp?rev=changeset%2Fcumulus%2F2021-11-02_13.57.25_5Z1H
{
  "autonomous-system": 65999,
  "enable": "on"
}

Configuration Apply Fails with Warnings

In some cases, such as the first push with NVUE or if you change a file manually instead of using NVUE, you see a warning prompt and the apply fails:

$ curl -u 'cumulus:cumulus' --insecure -X GET https://127.0.0.1:8765/nvue_v1/revision/changeset%2Fcumulus%2F2021-11-02_16.09.18_5Z1K
{
  "changeset/cumulus/2021-11-02_16.09.18_5Z1K": {
    "state": "ays_fail",
    "transition": {
      "issue": {
        "0": {
          "code": "client_timeout",
          "data": {},
          "message": "Timeout while waiting for client response",
          "severity": "error"
        }
      },
      "progress": "Aborted apply after warnings"
    }
  }

To resolve this issue, include "auto-prompt":{"ays": "ays_yes"} to the configuration apply:

$ curl -u 'cumulus:cumulus' -d '{"state":"apply","auto-prompt":{"ays": "ays_yes"}}' -H 'Content-Type:application/json' --insecure -X PATCH https://127.0.0.1:8765/nvue_v1/revision/changeset%2Fcumulus%2F2021-11-02_16.09.18_5Z1K

NVUE REST API Documentation

For information about using the NVUE REST API, refer to the NVUE API documentation.

NVUE CLI

The NVUE CLI has a flat structure as opposed to a modal structure. This means that you can run all commands from the primary prompt instead of only in a specific mode.

Command Syntax

NVUE commands all begin with nv and fall into one of three syntax categories:

• Configuration (nv set and nv unset)
• Monitoring (nv show)
• Configuration management (nv config).

Command Completion

As you enter commands, you can get help with the valid keywords or options using the Tab key. For example, using Tab completion with nv set displays the possible options for the command and returns you to the command prompt to complete the command.

cumulus@switch:~$ nv set <<press Tab>>
acl        evpn       mlag       platform   router     system     
bridge     interface  nve        qos        service    vrf 

cumulus@switch:~$ nv set

Command Help

As you enter commands, you can get help with command syntax by entering -h or --help at various points within a command entry. For example, to examine the options available for nv set interface, enter nv set interface -h or nv set interface --help.

cumulus@switch:~$ nv set interface -h
Usage:
  nv set interface [options] <interface-id> ...

Description:
  Interfaces

Identifiers:
  <interface-id>    Interface

General Options:
  -h, --help        Show help.

Command List

You can list all the NVUE commands by running nv list-commands. See List All NVUE Commands below.

Command History

At the command prompt, press the Up Arrow and Down Arrow keys to move back and forth through the list of commands you entered. When you find a given command, you can run the command by pressing Enter. Optionally, you can modify the command before you run it.

Command Categories

The NVUE CLI has a flat structure; however, the commands are in three functional categories:

• Configuration
• Monitoring
• Configuration Management

Configuration Commands

The NVUE configuration commands modify switch configuration. You can set and unset configuration options.

The nv set and nv unset commands are in the following categories. Each command group includes subcommands. Use command completion (Tab key) to list the subcommands.

Monitoring Commands

The NVUE monitoring commands show various parts of the network configuration. For example, you can show the complete network configuration or only interface configuration. The monitoring commands are in the following categories. Each command group includes subcommands. Use command completion (Tab key) to list the subcommands.

The following example shows the nv show router commands after pressing the TAB key, then shows the output of the nv show router bgp command.

cumulus@leaf01:mgmt:~$ nv show router <<TAB>>
bgp     ospf    pbr     policy
cumulus@leaf01:mgmt:~$ nv show router bgp
                                operational  applied  pending      description
------------------------------  -----------  -------  -----------  ----------------------------------------------------------------------
enable                                       off      on           Turn the feature 'on' or 'off'.  The default is 'off'.
autonomous-system                                     none         ASN for all VRFs, if a single AS is in use.  If "none", then ASN mu...
graceful-shutdown                                     off          Graceful shutdown enable will initiate the GSHUT community to be an...
policy-update-timer                                   5            Wait time in seconds before processing updates to policies to ensur...
router-id                                             none         BGP router-id for all VRFs, if a common one is used.  If "none", th...
wait-for-install                                      off          bgp waits for routes to be installed into kernel/asic before advert...
convergence-wait
  establish-wait-time                                 0            Maximum time to wait to establish BGP sessions. Any peers which do...
  time                                                0            Time to wait for peers to send end-of-RIB before router performs pa...
graceful-restart
  mode                                                helper-only  Role of router during graceful restart. helper-only, router is in h...
  path-selection-deferral-time                        360          Used by the restarter as an upper-bounds for waiting for peering es...
  restart-time                                        120          Amount of time taken to restart by router. It is advertised to the...
  stale-routes-time                                   360          Specifies an upper-bounds on how long we retain routes from a resta...
cumulus@leaf01:mgmt:~$ 

Additional options are available for the nv show commands. For example, you can choose the configuration you want to show (pending, applied, startup, or operational). You can also turn on colored output, and paginate specific output.

The following example shows pending BGP graceful restart configuration:

cumulus@switch:~$ nv show router bgp graceful-restart --pending
                             pending_20210128_212626_4WSY  description
----------------------------  ----------------------------  ----------------------------------------------------------------------
mode                          helper-only                   Role of router during graceful restart. helper-only, router is in h...
path-selection-deferral-time  360                           Used by the restarter as an upper-bounds for waiting for peeringes...
restart-time                  120                           Amount of time taken to restart by router. It is advertised to the...
stale-routes-time             360                           Specifies an upper-bounds on how long we retain routes from a resta...

Net Show commands

In addition to the nv show commands, Cumulus Linux continues to provide a subset of the NCLU net show commands. Use these commands to get additional views of various parts of your network configuration.

cumulus@leaf01:mgmt:~$ net show 
    bfd            :  Bidirectional forwarding detection
    bgp            :  Border Gateway Protocol
    bridge         :  a layer2 bridge
    clag           :  Multi-Chassis Link Aggregation
    commit         :  apply the commit buffer to the system
    configuration  :  settings, configuration state, etc
    counters       :  net show counters
    debugs         :  Debugs
    dhcp-snoop     :  DHCP snooping for IPv4
    dhcp-snoop6    :  DHCP snooping for IPv6
    dot1x          :  Configure, Enable, Delete or Show IEEE 802.1X EAPOL
    evpn           :  Ethernet VPN
    hostname       :  local hostname
    igmp           :  Internet Group Management Protocol
    interface      :  An interface, such as swp1, swp2, etc.
    ip             :  Internet Protocol version 4/6
    ipv6           :  Internet Protocol version 6
    lldp           :  Link Layer Discovery Protocol
    mpls           :  Multiprotocol Label Switching
    mroute         :  Static unicast routes in MRIB for multicast RPF lookup
    msdp           :  Multicast Source Discovery Protocol
    neighbor       :  A BGP, OSPF, PIM, etc neighbor
    ospf           :  Open Shortest Path First (OSPFv2)
    ospf6          :  Open Shortest Path First (OSPFv3)
    package        :  A Cumulus Linux package name
    pbr            :  Policy Based Routing
    pim            :  Protocol Independent Multicast
    port-mirror    :  port-mirror
    port-security  :  Port security
    ptp            :  Precision Time Protocol
    roce           :  Enable RoCE on all interfaces, default mode is lossless
    rollback       :  revert to a previous configuration state
    route          :  EVPN route information
    route-map      :  Route-map
    snmp-server    :  Configure the SNMP server
    system         :  System
    time           :  Time
    version        :  Version number
    vrf            :  Virtual routing and forwarding
    vrrp           :  Virtual Router Redundancy Protocol

Configuration Management Commands

The NVUE configuration management commands manage and apply configurations.

You can use the NVUE configuration management commands to back up and restore configuration when you upgrade Cumulus Linux on the switch. Refer to Upgrading Cumulus Linux.

List All NVUE Commands

To show the full list of NVUE commands, run nv list-commands. For example:

cumulus@switch:~$ nv list-commands
nv show router
nv show router nexthop-group
nv show router nexthop-group <nexthop-group-id>
nv show router nexthop-group <nexthop-group-id> via
nv show router nexthop-group <nexthop-group-id> via <via-id>
nv show router pbr
nv show router pbr map
nv show router pbr map <pbr-map-id>
nv show router pbr map <pbr-map-id> rule
nv show router pbr map <pbr-map-id> rule <rule-id>
nv show router pbr map <pbr-map-id> rule <rule-id> match
nv show router pbr map <pbr-map-id> rule <rule-id> action
nv show router policy
nv show router policy community-list
...

You can show the list of commands for a command grouping. For example, to show the list of interface commands:

cumulus@switch:~$ nv list-commands interface
nv show interface
nv show interface <interface-id>
nv show interface <interface-id> router
nv show interface <interface-id> router pbr
nv show interface <interface-id> router ospf
nv show interface <interface-id> router ospf timers
nv show interface <interface-id> router ospf authentication
nv show interface <interface-id> router ospf bfd
nv show interface <interface-id> bond
nv show interface <interface-id> bond member
nv show interface <interface-id> bond member <member-id>
nv show interface <interface-id> bond mlag
nv show interface <interface-id> bridge
...

Use the Tab key to get help for the command lists you want to see. For example, to show the list of command options available for the interface swp1, run:

cumulus@switch:~$ nv list-commands interface swp1 <<press Tab>>
acl     bond    bridge  evpn    ip      link    ptp     qos     router 

NVUE Configuration File

When you save network configuration using NVUE, Cumulus Linux writes the configuration to the /etc/nvue.d/startup.yaml file.

You can edit or replace the contents of the /etc/nvue.d/startup.yaml file. NVUE applies the configuration in the /etc/nvue.d/startup.yaml file during system boot only if the nvue-startup.service is running. If this service is not running, the switch reboots with the same configuration that is running before the reboot.

To start nvue-startup.service:

cumulus@switch:~$ sudo systemctl enable nvue-startup.service
cumulus@switch:~$ sudo systemctl start nvue-startup.service

When you apply a configuration with nv config apply, NVUE also writes to underlying Linux files such as /etc/network/interfaces and /etc/frr/frr.conf. You can view these configuration files; however NVIDIA recommends that you do not manually edit them while using NVUE. If you need to configure certain network settings manually or use automation such as Ansible to configure the switch, see Configure NVUE to Ignore Linux Files below.

Configure NVUE to Ignore Linux Files

You can configure NVUE to ignore certain underlying Linux files when applying configuration changes. For example, if you push certain configuration to the switch using Ansible and Jinja2 file templates or you want to use custom configuration for a particular service such as PTP, you can ensure that NVUE never writes to those configuration files.

The following example configures NVUE to ignore the Linux /etc/ptp4l.conf file when applying configuration changes and saves the configuration so it persists after a reboot.

cumulus@switch:~$ nv set system config apply ignore /etc/ptp4l.conf
cumulus@switch:~$ nv config apply
cumulus@switch:~$ nv config save

Example Configuration Commands

This section provides examples of how to configure a Cumulus Linux switch using NVUE commands.

Configure the System Hostname

The example below shows the NVUE commands required to change the hostname for the switch to leaf01:

cumulus@switch:~$ nv set system hostname leaf01
cumulus@switch:~$ nv config apply

Configure the System DNS Server

The example below shows the NVUE commands required to define the DNS server for the switch:

cumulus@switch:~$ nv set service dns mgmt server 192.168.200.1
cumulus@switch:~$ nv config apply

Configure an Interface

The example below shows the NVUE commands required to bring up swp1.

cumulus@switch:~$ nv set interface swp1
cumulus@switch:~$ nv config apply 

Configure a Bond

The example below shows the NVUE commands required to configure the front panel port interfaces swp1 thru swp4 to be slaves in bond0.

cumulus@switch:~$ nv set interface bond0 bond member swp1-4
cumulus@switch:~$ nv config apply

Configure a Bridge

The example below shows the NVUE commands required to create a VLAN-aware bridge that contains two switch ports (swp1 and swp2) and includes 3 VLANs; tagged VLANs 10 and 20 and an untagged (native) VLAN of 1.

With NVUE, there is a default bridge called br_default, which has no ports assigned to it. The example below configures this default bridge.

cumulus@switch:~$ nv set interface swp1-2 bridge domain br_default
cumulus@switch:~$ nv set bridge domain br_default vlan 10,20
cumulus@switch:~$ nv set bridge domain br_default untagged 1
cumulus@switch:~$ nv config apply

Configure MLAG

The example below shows the NVUE commands required to configure MLAG on leaf01. The commands:

• Place swp1 into bond1 and swp2 into bond2.
• Configure the MLAG ID to 1 for bond1 and to 2 for bond2.
• Add bond1 and bond2 to the default bridge (br_default).
• Create the inter-chassis bond (swp49 and swp50) and the peer link (peerlink)
• Set the peer link IP address to linklocal, the MLAG system MAC address to 44:38:39:BE:EF:AA, and the backup interface to 10.10.10.2.

cumulus@leaf01:~$ nv set interface bond1 bond member swp1
cumulus@leaf01:~$ nv set interface bond2 bond member swp2
cumulus@leaf01:~$ nv set interface bond1 bond mlag id 1
cumulus@leaf01:~$ nv set interface bond2 bond mlag id 2
cumulus@switch:~$ nv set interface bond1-2 bridge domain br_default 
cumulus@leaf01:~$ nv set interface peerlink bond member swp49-50
cumulus@leaf01:~$ nv set mlag mac-address 44:38:39:BE:EF:AA
cumulus@leaf01:~$ nv set mlag backup 10.10.10.2
cumulus@leaf01:~$ nv set mlag peer-ip linklocal
cumulus@leaf01:~$ nv config apply

Configure BGP Unnumbered

The example below shows the NVUE commands required to configure BGP unnumbered on leaf01. The commands:

• Assign the ASN for this BGP node to 65101.
• Set the router ID to 10.10.10.1.
• Distribute routing information to the peer on swp51.
• Originate prefixes 10.10.10.1/32 from this BGP node.

cumulus@leaf01:~$ nv set router bgp autonomous-system 65101
cumulus@leaf01:~$ nv set router bgp router-id 10.10.10.1
cumulus@leaf01:~$ nv set vrf default router bgp neighbor swp51 remote-as external
cumulus@leaf01:~$ nv set vrf default router bgp address-family ipv4-unicast network 10.10.10.1/32
cumulus@leaf01:~$ nv config apply

Example Monitoring Commands

This section provides monitoring command examples.

Show Installed Software

The following example command lists the software installed on the switch:

cumulus@switch:~$ nv show platform software
Installed Software
=====================
                      description                                                     package                version
--------------------- ----------------------------                                    --------------------   ------------
acpi                  displays information on ACPI devices                            acpi                   1.7-1.1                   
acpi-support-base     scripts for handling base ACPI events such as the power button  acpi-support-base      0.142-8
acpid                 Advanced Configuration and Power Interface event daemon         acpid                  1:2.0.31-1
adduser               add and remove users and groups                                 adduser                3.118
apt                   commandline package manager                                     apt                    1.8.2.3
arping                sends IP and/or ARP pings (to the MAC address)                  arping                 2.19-6
arptables             ARP table administration                                        arptables              0.0.4+snapshot20181021-4
atftp                 advanced TFTP client                                            atftp                  0.7.git20120829-3.2~deb10u1                 
atftpd                advanced TFTP server                                            atftpd                 0.7.git20120829-3.2~deb10u1 
auditd                User space tools for security auditing                          auditd                 1:2.8.4-3              
base-files            Debian base system miscellaneous files                          base-files             10.3+deb10u9                 
base-passwd           Debian base system master password and group files              base-passwd            3.5.46 
bash                  GNU Bourne Again SHell                                          bash                   5.0-4
...

Show Interface Configuration

The following example command shows the running, applied, and pending swp1 interface configuration.

cumulus@leaf01:~$ nv show interface swp1
                         operational  applied  description
-----------------------  -----------  -------  ----------------------------------------------------------------------
type                     swp                   The type of interface
ip
  [address]                                    ipv4 and ipv6 address
link
  mtu                    9216                  interface mtu
  state                  down                  The state of the interface
  stats
    carrier-transitions  3                     Number of times the interface state has transitioned between up and...
    in-bytes             300 Bytes             total number of bytes received on the interface
    in-drops             5                     number of received packets dropped
    in-errors            0                     number of received packets with errors
    in-pkts              5                     total number of packets received on the interface
    out-bytes            0 Bytes               total number of bytes transmitted out of the interface
    out-drops            0                     The number of outbound packets that were chosen to be discarded eve...
    out-errors           0                     The number of outbound packets that could not be transmitted becaus...
    out-pkts             0                     total number of packets transmitted out of the interface
...

Example Configuration Management Commands

This section provides examples of how to use the configuration management commands to apply, save, and detach configurations.

Apply and Save a Configuration

The following example command configures the front panel port interfaces swp1 thru swp4 to be slaves in bond0. The configuration is only in a pending configuration state. The configuration is not applied. NVUE has not yet made any changes to the running configuration.

cumulus@switch:~$ nv set interface bond0 bond member swp1-4

To apply the pending configuration to the running configuration, run the nv config apply command. The configuration does not persist after a reboot.

cumulus@switch:~$ nv config apply

To save the applied configuration to the startup configuration, run the nv config save command. This command overwrites the startup configuration with the applied configuration by writing to the /etc/nvue.d/startup.yaml file. The configuration persists after a reboot.

cumulus@switch:~$ nv config save

Detach a Pending Configuration

The following example configures the IP address of the loopback interface, then detaches the configuration from the current pending configuration. Cumulus Linux saves the detached configuration to a file changeset/cumulus/<date>_<time>_xxxx that includes a timestamp with extra characters to distinguish it from other pending configurations; for example, changeset/cumulus/2021-06-11_18.35.06_FPKP.

cumulus@switch:~$ nv set interface lo ip address 10.10.10.1
cumulus@switch:~$ nv config detach

View Differences Between Configurations

To view differences between configurations, run the nv config diff command.

To view differences between two detached pending configurations, run the nv config diff «TAB» command to list all the current detached pending configurations, then run the nv config diff command with the pending configurations you want to diff:

cumulus@switch:~$ nv config diff <<press Tab>>
applied                                     changeset/cumulus/2021-06-11_18.35.06_FPKP
changeset/cumulus/2021-06-11_16.16.41_FPKK  empty
changeset/cumulus/2021-06-11_17.05.12_FPKN  startup

cumulus@switch:~$ nv config diff changeset/cumulus/2021-06-11_18.35.06_FPKP changeset/cumulus/2021-06-11_17.05.12_FPKN

To view differences between a detached pending configuration and the applied configuration:

cumulus@switch:~$ nv config diff changeset/cumulus/2021-06-11_18.35.06_FPKP applied

Replace and Patch a Pending Configuration

The following example replaces the pending configuration with the contents of the YAML configuration file called nv-02/13/2021.yaml located in the /deps directory:

cumulus@switch:~$ nv config replace /deps/nv-02/13/2021.yaml

The following example patches the pending configuration (runs the set or unset commands from the configuration in the nv-02/13/2021.yaml file located in the /deps directory):

cumulus@switch:~$ nv config patch /deps/nv-02/13/2021.yaml

Flexible Snippet Architecture

If you configure Cumulus Linux with NVUE commands, then want to configure a feature that does not yet support the NVUE Object Model, you can create a snippet in yaml format and add the configuration to either the /etc/frr/frr.conf or /etc/network/interfaces file.

cumulus@switch:~$ sudo nano ./mlag_snippet.yaml
- set:
    system:
      config:
        snippet:
          ifupdown2_eni:
            peerlink.4094: |
              clagd-args --peerTimeout 400

cumulus@switch:~$ sudo nano ./bridge_snippet.yaml
- set:
    system:
     config:
       snippet:
         ifupdown2_eni:
           eni_stanzas: |
             auto br0
             iface br0
               address 11.0.0.10/24
               bridge-ports swp1 swp2
               bridge-vlan-aware no

How Is NVUE Different from NCLU?

This section lists some of the differences between NVUE CLI and the NCLU CLI.

Configuration File

When you save network configuration using NVUE, Cumulus Linux saves the configuration in the /etc/nvue.d/startup.yaml file.

NVUE also writes to underlying Linux files when you apply a configuration, such as the /etc/network/interfaces and /etc/frr/frr.conf files. You can view these configuration files; however NVIDIA recommends that you do not manually edit them while using NVUE.

Bridge Configuration

You set global bridge configuration on the bridge domain. For example:

cumulus@leaf01:~$ nv set bridge domain br_default vlan 10,20

However, you set specific bridge interface options with interface commands. For example:

cumulus@leaf01:~$ nv set interface swp1 bridge domain br_default learning on

The default VLAN-aware bridge in NVUE is br_default. The default VLAN-aware bridge in NCLU is bridge.

BGP Configuration

You can set global BGP configuration, such as the ASN, router ID, graceful shutdown and restart with the nv set router bgp command. For example:

cumulus@leaf01:~$ nv set router bgp autonomous-system 65101

However, BGP peer and peer group, route information, timer, and address family configuration requires a VRF. For example:

cumulus@leaf01:~$ nv set vrf default router bgp neighbor swp51 remote-as external