Configure Advanced Options for BGP on FTD

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Updated:July 17, 2026
Document ID:220601

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Introduction

This document describes how to use the Border Gateway Protocol (BGP) to manipulate Path Selection when multiple routes exist for the same destination.

Prerequisites

Requirements

There are no specific requirements for this document.

Components Used

This document is not restricted to specific hardware and software versions.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, ensure that you understand the potential impact of any command.

Configure BGP AS Path Prepend 

You can use AS Path Prepend to manipulate the path selection. Refer to the BGP Path Selectiondocumentation for more information.

Procedure

Step 1. Click Objects >Route Map.

Step 2. Select the Route Map you have assigned to the BGP peer where you must apply the AS Path Prepend or add a new Route Map by clicking Add Route Map.

Step 3. Configure the name of the Route Map, then click Add under the Entries section.

New Route Map Object

Step 4. Configure at least the next basic settings:

        • Sequence No. - Select the number of the sequence.
        • Redistribution - Select Allow.

Add Route Map Entry - Sequence and Distribution

Step 5. Optional: You can specify multiple variables like Prefix-List and Access lists in the Match Classes section.

Step 6.Click Set Clauses> BGP Clauses> AS Path. Configure the Prepend option based on the next options:

        • Prepend AS Path - Add the AS you want to add to the Path, separated by commas.
        • Prepend last AS to the AS Path - Select the number of times you want to add the last AS to the AS path (you can add the AS up to 10 times).

Add Route Map Entry - Prepend AS Path

Step 7.Click Add >Save.

Step 8. Click Device >Device Management, and select the Device you want to apply the AS Path Prepend.

Step 9. Click Routing >IPv4 in the BGP section, then Neighbor.

Step 10. Click the Edit icon for the Neighbor you want to apply the AS Path Prepend. On the Filtering Routes section, select the Route Map from the drop-down menu in the Incoming or Outgoing traffic in the Route Map section.

Edit Neighbor - Route Map

Step 11. Click OK>Save.

Configure BGP Local Preference

You can use Local Preference to manipulate the locally path selection. Refer to the BGP Path Selection for more information on BGP path selection.

Procedure

Step 1.Click Objects >Route Map.

Step 2. Select the Route Map you assigned to the BGP peer where you applied the Local Preference or add a new Route Map by clicking Add Route Map.

Step 3. Configure the Name of the Route Map, then click Add under the Entries section.

Edit Route Map Object

Step 4. Configure at a minimum, the next basic settings:

        • Sequence No. - Select the number of the sequence.
        • Redistribution -  Select Allow.

Add Route Map Entry

Step 5. Optional - You can specify multiple variables like Prefix-List and Access lists in the Match Classes section.

Step 6. Click Set Clauses> BGP Clauses> Others. Configure the Local Preference where you want to apply to the Local Preference section.

Add Route Map Entry Local Preference

Step 7.Click Add >Save.

Step 8.Click Device> Device Management, and select the Device you want to apply to the Local Preference.

Step 9.Click Routing >IPv4 in the BGP section, then Neighbor.

Step 10. Click the Edit icon for the Neighbor you want to apply the AS Local Preference. On the Filtering Routes section, select the Route Map from the drop-down menu in the Incoming or Outgoing traffic in the Route Map section.

Edit Neighbor Route Map

Step 11.Click OK >Save.

Configure BGP Weight

You can use Weight to manipulate the locally path selection. Refer to the BGP Path Selection for more information on BGP path selection.

Procedure

Step 1.Click Objects >Route Map.

Step 2. Select the Route Map you assigned to the BGP peer where you applied the Local Preference or add a new Route Map by clicking Add Route Map.

Step 3. Configure the Name of the Route Map, then click Add under the Entries section.

Edit Route Map Object Weight RM

Step 4. Configure at least the next basic settings:

        • Sequence No. - Select the number of the sequence.
        • Redistribution - Select Allow.

Add Route Map Entry - Sequence Number

Step 5. Optional: You can specify multiple variables like Prefix-List and Access lists in the Match Classes section.

Step 6.Click Set Clauses >BGP Clauses >Others. Configure the Weight to apply in the Set Weight section.

Add Route Map Entry - Set Weight

Step 7.Click Add >Save.

Step 8.Click Device >Device Management, and select the Device to apply the Local Preference.

Step 9.Click Routing >IPv4 in the BGP section, then Neighbor.

Step 10.Click the Edit icon for the Neighbor you want to apply the Weight. On the Filtering Routes section, select the Route Map from the drop-down menu in the Incoming or Outgoing traffic in the Route Map section.

Edit Neighbor Route Map Weight

Step 11.Click OK >Save.

BGP AS Path Filter

You can Allow or Block prefixes from certain autonomous systems. FTD allows you to filter based on Regular Expressions. Refer to the documentation for more information on Use on Regular Expressions in BGP. 

Procedure

Step 1.Click Objects >AS Path.

Step 2. Configure at least the next basic settings:

        • Name - Select the number to the AS Path Object.
        • Sequence No. - Click Add under the Entries section, then Allow or Deny based on the action you want to take. Configure the Regular Expression you to use, then click Add >Save.

New AS Path Object

Add AS Path Entry

Step 3.Optional: You can configure the AS Path Object directly on the peer or into a Route Map. If you want to configure directly on the peer, click the Edit icon for the Neighbor where you want to apply the AS Path Filter. On the Filtering Routes section, select the AS Path Object from the drop-down menu in the Incoming or Outgoing traffic in the AS Path Filter section.

Edit Neighbor - AS Path Filter

Step 3.Click Objects >Route Map.

Step 4. Select the Route Map you assigned to the BGP peer where applied the Path Filter or add a new Route Map by clicking Add Route Map.

Step 5. Configure the Name of the Route Map, then click Add under the Entries section.

Edit Route Map Object - Path Filter RM

Step 6. Configure at least the next basic settings:

        • Sequence No. - Select the number of the sequence.
        • Redistribution - Select Allow (the action on the traffic is defined in Sequence No. In Step 2).

Set Clauses

Step 7. Click Match Clauses >BGP and select the AS Path Object created in Step 1, then click Add.

Match Clauses

Step 8. Click Save.

Step 9.Click Device >Device Management, and select the Device to apply the Regular Expression.

Step 10.Click Routing >IPv4 in the BGP section, then Neighbor.

Step 11.Click the Edit icon for the Neighbor where you want to apply the AS Path Filter. On the Filtering Routes section, select the Route Map from the drop-down menu in the Incoming or Outgoing traffic in the Route Map section.

Edit Neighbor - Path Filter RM

Step 12. Click OK >Save.

Revision History

Revision Publish Date Comments
3.0
17-Jul-2026
Updated description, spacing, grammar, sentence structure, added lines to separate sections/readability, and fixed any CCW alerts..
2.0
10-Apr-2025
Added Alt Text. Updated Formatting to meet Cisco Guidelines.
1.0
21-Jul-2023
Initial Release
TAC Authored

Contributed by Cisco Engineers

  • Erick Leobardo Perez
    Technical Consulting Engineer

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