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Configuring Forwarding


In Contrail, the default forwarding mode is enabled for fallback bridging (IP FIB and MAC FIB). The mode can be changed, either through the Contrail Web UI or by using python provisioning commands.

To change the forwarding mode:

  1. From the Contrail Web UI, select Configure > Networking > Networks.
  2. Select the virtual network that you want to change the forwarding mode for.
  3. Click the gear icon and select Edit.

    The Edit Network window is displayed as shown in Figure 1.

    Figure 1: Edit Network Window
    Edit Network Window

    Under the Advanced Options select the forwarding mode from the following choices:

    • Select Default to enable the default forwarding mode.

    • Select L2 and L3 to enable IP and MAC FIB (fallback bridging).

    • Select L2 Only to enable only MAC FIB.

    • Select L3 Only to enable only IP.


The full list of forwarding modes are only displayed if you change entries in the /usr/src/contrail/contrail-web-core/config/ file. For example:

  1. To make the L2 selection available locate the following:
  2. Change the entry to the following:
  3. To make the other selections available, modify the corresponding entries.
  4. Save the file and quit the editor.
  5. Restart the Contrail Web user interface process (webui).

Alternatively, you can use the following python provisioning command to change the forwarding mode:

python provisioning_forwarding_mode --project_fq_name 'defaultdomain: admin' --vn_name vn1 --forwarding_mode < l2_l3| l2 >


l2_l3 = Enable IP FIB and MAC FIB (fallback bridging)

l2 = Enable MAC FIB only (Layer 2 only)