Loopback Interface

Loopback interfaces are virtual interfaces used for management access, routing protocols, and NAT. The scm CLI provides commands to create, update, delete, and load loopback interfaces.

Overview

The loopback-interface commands allow you to:

• Create loopback interfaces with IP addressing
• Update existing loopback interface configurations
• Delete loopback interfaces that are no longer needed
• Bulk import loopback interfaces from YAML files
• Export loopback interfaces for backup or migration

Set Loopback Interface

Create or update a loopback interface.

Syntax

scm set network loopback-interface NAME [OPTIONS]

Arguments

Argument	Description	Required
NAME	Name of the loopback interface	Yes

Options

Option	Description	Required
--folder TEXT	Folder location	Yes*
--snippet TEXT	Snippet location	Yes*
--device TEXT	Device location	Yes*
--comment TEXT	Interface description	No
--default-value TEXT	Default interface (e.g. loopback.1)	No
--mtu INTEGER	MTU (576-9216)	No
--ip-json TEXT	Static IPs as JSON	No
--ipv6-json TEXT	IPv6 config as JSON	No

* Exactly one of --folder, --snippet, or --device is required.

Examples

Create a Loopback Interface

$ scm set network loopback-interface loopback.1 \
    --folder Texas \
    --ip-json '[{"name": "10.0.0.1/32"}]' \
    --comment "Management loopback"
---> 100%
Created loopback interface: loopback.1 in folder Texas

Create a Loopback with IPv6

$ scm set network loopback-interface loopback.2 \
    --folder Texas \
    --ip-json '[{"name": "10.0.0.2/32"}]' \
    --ipv6-json '{"addresses": [{"name": "fd00::1/128"}]}' \
    --comment "Dual-stack loopback"
---> 100%
Created loopback interface: loopback.2 in folder Texas

Delete Loopback Interface

Delete a loopback interface from SCM.

Syntax

scm delete network loopback-interface NAME [OPTIONS]

Arguments

Argument	Description	Required
NAME	Name of the loopback interface to delete	Yes

Options

Option	Description	Required
--folder TEXT	Folder location	Yes*
--snippet TEXT	Snippet location	Yes*
--device TEXT	Device location	Yes*
--force	Skip confirmation prompt	No

* Exactly one of --folder, --snippet, or --device is required.

Example

$ scm delete network loopback-interface loopback.1 --folder Texas --force
---> 100%
Deleted loopback interface: loopback.1 from folder Texas

Load Loopback Interface

Load multiple loopback interfaces from a YAML file.

Syntax

scm load network loopback-interface [OPTIONS]

Options

Option	Description	Required
--file TEXT	Path to YAML file	Yes
--folder TEXT	Override folder location for all objects	No
--snippet TEXT	Override snippet location for all objects	No
--device TEXT	Override device location for all objects	No
--dry-run	Preview changes without applying	No

YAML File Format

---
loopback_interfaces:
  - name: loopback.1
    folder: Texas
    comment: "Management loopback"
    ip:
      - name: "10.0.0.1/32"

  - name: loopback.2
    folder: Texas
    comment: "Routing protocol loopback"
    ip:
      - name: "10.0.0.2/32"

Examples

Load with Original Locations

$ scm load network loopback-interface --file loopbacks.yml
---> 100%
✓ Loaded loopback interface: loopback.1
✓ Loaded loopback interface: loopback.2

Successfully loaded 2 out of 2 loopback interfaces from 'loopbacks.yml'

Load with Folder Override

$ scm load network loopback-interface --file loopbacks.yml --folder Austin
---> 100%
✓ Loaded loopback interface: loopback.1
✓ Loaded loopback interface: loopback.2

Successfully loaded 2 out of 2 loopback interfaces from 'loopbacks.yml'

note

When using container override options (--folder, --snippet, --device), all loopback interfaces will be loaded into the specified container, ignoring the container specified in the YAML file.

Show Loopback Interface

Display loopback interface objects.

Syntax

scm show network loopback-interface [NAME] [OPTIONS]

Arguments

Argument	Description	Required
NAME	Name of the loopback interface to show; omit to list all	No

Options

Option	Description	Required
--folder TEXT	Folder location	Yes*
--snippet TEXT	Snippet location	Yes*
--device TEXT	Device location	Yes*
--max-results INTEGER	Maximum number of results to display	No
--output [table|json|yaml]	Output format (default: table)	No

* Exactly one of --folder, --snippet, or --device is required.

note

When no NAME argument is provided, all items are listed by default.

Examples

Show Specific Loopback Interface

$ scm show network loopback-interface loopback.1 --folder Texas
---> 100%
Loopback Interface: loopback.1
  Location: Folder 'Texas'
  Comment: Management loopback
  IP: 10.0.0.1/32

List All Loopback Interfaces (Default Behavior)

$ scm show network loopback-interface --folder Texas
---> 100%
Loopback interfaces in folder 'Texas':
------------------------------------------------------------
Name: loopback.1
  Comment: Management loopback
  IP: 10.0.0.1/32
------------------------------------------------------------
Name: loopback.2
  Comment: Routing protocol loopback
  IP: 10.0.0.2/32
------------------------------------------------------------

Backup Loopback Interfaces

Backup all loopback interface objects from a specified location to a YAML file.

Syntax

scm backup network loopback-interface [OPTIONS]

Options

Option	Description	Required
--folder TEXT	Folder location	No*
--snippet TEXT	Snippet location	No*
--device TEXT	Device location	No*
--file TEXT	Custom output filename	No

* One of --folder, --snippet, or --device is required.

Examples

Backup from Folder

$ scm backup network loopback-interface --folder Texas
---> 100%
Successfully backed up 4 loopback interfaces to loopback_interface_folder_texas_20240115_120530.yaml

Backup with Custom Filename

$ scm backup network loopback-interface --folder Texas --file texas-loopbacks.yaml
---> 100%
Successfully backed up 4 loopback interfaces to texas-loopbacks.yaml

Best Practices

1. Use /32 Addresses: Assign /32 subnet masks to loopback interfaces as they represent a single host address.
2. Dedicate for Routing: Use dedicated loopback interfaces for routing protocol peering (BGP, OSPF).
3. Add Descriptive Comments: Document the purpose of each loopback interface for easier management.
4. Test with Dry Run: Use --dry-run when loading configurations to preview changes before applying.
5. Backup Before Changes: Always backup existing loopback configurations before making bulk modifications.