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Chapter 15. Creating a dummy interface

As a Red Hat Enterprise Linux user, you can create and use dummy network interfaces for debugging and testing purposes. A dummy interface provides a device to route packets without actually transmitting them. It enables you to create additional loopback-like devices managed by NetworkManager and makes an inactive SLIP (Serial Line Internet Protocol) address look like a real address for local programs.

15.1. Creating a dummy interface with both an IPv4 and IPv6 address using nmcli

You can create a dummy interface with various settings, such as IPv4 and IPv6 addresses. After creating the interface, NetworkManager automatically assigns it to the default public firewalld zone.


  • Create a dummy interface named dummy0 with static IPv4 and IPv6 addresses:

    # nmcli connection add type dummy ifname dummy0 ipv4.method manual ipv4.addresses ipv6.method manual ipv6.addresses 2001:db8:2::1/64

    To configure a dummy interface without IPv4 and IPv6 addresses, set both the ipv4.method and ipv6.method parameters to disabled. Otherwise, IP auto-configuration fails, and NetworkManager deactivates the connection and removes the device.


  • List the connection profiles:

    # nmcli connection show
    NAME            UUID                                  TYPE     DEVICE
    dummy-dummy0    aaf6eb56-73e5-4746-9037-eed42caa8a65  dummy    dummy0

Additional resources

  • nm-settings(5) man page