BGP Advertisement Configuration
Introduction
Forward Platform can model L3 VPNs, Internet Nodes and Intranet Nodes using BGP advertisements.
For L3 VPNs the modeling is done without the need to collect from the Provider Edge (PE) and Provider (P) routers by taking inbound and outbound routing policies into consideration.
This is achieved by collecting the BGP advertised routes (Adj-RIB-Out post-policy) from the Customer Edge (CE) routers in addition to their respective RIB tables.
For Internet Nodes and Intranet Nodes the site subnets are auto discovered by inferring them from BGP routes in the connected gateway‘s routing table.
Be aware of the following restrictions:
- The model enhancement requires the PE-CE protocol to be eBGP. Any other dynamic routing protocol or static routing is not supported and will result in fallback to standard model where only the RIB table is used to deduce the paths via the given network (no routing policies and filters are taken into consideration).
- CE routers cannot be connected to the synthetic device using their self interfaces.
- Support is available for common platforms like Cisco (IOS, IOS-XE, IOS-XR, NX-OS), Juniper (JUNOS) and Arista ( EOS). Please visit the Feature Matrix page for an updated list of supported platforms.
Configuration
BGP advertised routes from all adjacent devices must be collected to enable this enhancement.
For user convenience, BGP collection is enabled and configured to collect BGP Adj-RIB-Out when a given device is connected to L3 VPNs, Internet Nodes and Intranet Nodes .
To check or modify the per-device BGP collection settings, please visit the BGP Collection page to check or modify the per-device BGP collection settings.
By default the BGP advertisements are collect via device CLI. The Forward Collector supports the collection via BGP Monitoring Protocol (BMP) as well. For more info, please visit the Collecting With BMP page.
Before proceeding with creating the synthetic devices, make sure to include all CE routers in the snapshot.