Configure BGP Route Import/Export Settings

In BGP, you can implement an inter-virtual-router route leak by importing or exporting routes using the route target extended community of the destination and source virtual routers respectively. You can use a route map to filter the desired route targets instead of leaking the entire routing table. You can also leak the routes of global virtual router to user-defined virtual routers and vice versa.

  • You can configure BGP to leak routes between two user-defined virtual routers using the route target extended communities:

    • Tag the routes with the route targets from the source virtual router using route target export.

    • Import the routes that are matching the route targets in to the destination virtual router using route target import.

    • Optionally, you can filter routes from source virtual router or to destination virtual router using export or import route maps respectively. You can configure route map with match extended community list for filtering the routes. Similarly, you can configure route map with set extended community route targets to tag the routes with the route target extended community.

  • To import routes from the global virtual router to a user-defined virtual router, specify the IPv4/IPv6 route map in Global Virtual Router Import Route Map to import to the user-defined virtual router.

  • To export routes from a user-defined virtual router to the global virtual router, in addition to exporting the route targets, you can also specify the Global Virtual Router Export Route Map to export from the user-defined virtual router.

The BGP inter-virtual-router route leaking supports both ipv4 and ipv6 prefixes.

Before you begin

Procedure

Step 1

On the Device Management page, click Routing.

Step 2

(For a virtual-router-aware device) From the virtual routers drop-down, choose the virtual router for which you are configuring BGP.

Step 3

Choose BGP > IPv4 or IPv6.

Step 4

(Supported only for only virtual routers) Click Route Import/Export.

Step 5

In the Route Targets Import field, enter the route target extended community that you want to match for the routes to be imported. On deployment, the routes of the destination virtual router that matches this value is imported to the source virtual router's BGP table.

Note

  • The route target must be in ASN:nn format.

  • You can enter multiple route targets as comma separated values.

  • This value can range from 0:1 to 65534:65535.

Step 6

In the Route Targets Export field, enter the route target extended community to tag the source virtual router's routes with the route target value. On deployment, the routes of the source virtual router are tagged with this value.

Note

  • The route target must be in ASN:nn format.

  • You can enter multiple route targets as comma separated values.

  • This value can range from 0:1 to 65534:65535.

Step 7

Route maps help you to narrow down the routes to be shared instead of leaking the entire routing table. Route map filtering is applied on the list of routes that are obtained with the specified route target values:

  1. (Optional) Under User Virtual Router, choose the route map from the Import Route Map drop-down list to filter the routes at the destination virtual router.

    Note

    The user virtual router import route map is effective only when the route targets import is configured.

  2. (Optional) Under User Virtual Router, choose the route map from the Export Route Map drop-down list to filter the routes at the source virtual router before the routes are exported to other virtual routers.

    Note

    You can use the match and set clauses in the route map with the route target extended community lists for filtering based on other criteria or tagging the routes with the route target community values. For more information, see Route Map.

Step 8

To share the routes between a user-defined virtual router and global virtual router, specify the route map under the Global Virtual Router:

  1. To leak the global virtual router routes to the user-defined virtual router, select the route map from the Import Route Map drop-down list. The IPv4 or IPv6 route map is imported to the user-defined virtual router.

  2. To leak the user-defined virtual router routes to the global virtual router, select the route map from the Export Route Map drop-down list. The IPv4 or IPv6 route map is exported to the global virtual router.

    Note

    You must specify the route targets for export apart from specifying the route map.

Note

You can use the match clause of the route map object to filter the routes for leaking. For more information, see Route Map.

Step 9

Follow the procedure ( Step 3 to Step 8) to configure relevant BGP route import and export settings for other virtual routers as well.

Step 10

Click Save and Deploy.

When the packets flow into the ingress virtual router, BGP imports the routes from the destination virtual routers that have the matching route target value and if a route map is also configured, the routes are further filtered and used to identify the best path routes for routing the packets.