Advertise subscriber routes with BGP

Ella Core includes an embedded BGP speaker that advertises /32 host routes for each active subscriber IP. This guide walks through enabling BGP, adding a peer, and verifying the configuration.

For background on how Ella Core uses BGP, see the BGP Route Advertisement explanation.

NAT must be disabled

NAT and BGP are mutually exclusive. Disable NAT from the Networking > NAT tab before proceeding.

Enable BGP

1. Open the Ella Core UI and navigate to Networking > BGP.
2. Edit the BGP settings:
   • Local AS: Your autonomous system number (e.g. 64512).
   • Router ID: A unique IPv4 address identifying this BGP speaker, typically the N6 interface IP (e.g. 192.168.5.10).
   • Listen Address: The address and port to listen on (default :179). Change this only if you need BGP on a non-standard port.
3. Click Save.
4. Toggle BGP to ON.

Add a BGP peer

1. In the Networking > BGP tab, scroll to the Peers section.
2. Click Create.
3. Fill in the peer details:
   • Address: The IPv4 address of the upstream router (e.g. 192.168.5.1).
   • Remote AS: The AS number of the peer (e.g. 64513).
   • Hold Time: BGP hold timer in seconds (default 90). The keepalive interval is derived as hold time / 3 per RFC 4271.
   • Password (optional): MD5 authentication password. Must match the peer's configuration.
   • Description (optional): A label for the peer.
4. Click Create.

Verify advertised routes

View the advertised subscriber routes in the Advertised Routes table. The next-hop is always the N6 interface address.

Configure the upstream router

Ella Core advertises routes but does not receive them. You still need to configure the upstream router to:

1. Peer with Ella Core (matching the AS number and address configured above).
2. Accept all routes for subscriber data networks (e.g. 192.168.0.0/24)

Consult your router's documentation for BGP peering configuration.

Note

All steps in this guide can also be performed via the REST API. See the BGP API reference for details.