Perform the following task if you have BGP configured, and you want to enable ECMP over multiple autonomous systems. This task presumes that BGP is already configured. In the following figure, two ECMP paths to a destination go through two firewalls belonging to a single ISP in a single BGP autonomous system.
In the following figure, two ECMP paths to a destination go through two firewalls belonging to two different ISPs in different BGP autonomous systems.
Enable ECMP for BGP Autonomous Systems
Configure ECMP. See Configure ECMP on a Virtual Router.
For BGP routing, enable ECMP over multiple autonomous systems. Select Network > Virtual Routers and select the virtual router on which to enable ECMP for multiple BGP autonomous systems. Select BGP > Advanced and select ECMP Multiple AS Support.
Save the configuration. Click OK and Commit the configuration.

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