osrg-gobgp/docs/sources/route-reflector.md

Route Reflector

This page explains how to set up GoBGP as a route reflector.

Prerequisites

Assumed you finished Getting Started.

Configuration

Configure RouteReflector.RouteReflectorConfig section to enable route reflector functionality. The configuration below configures two route reflector clients and two normal iBGP peers.

[global.config]
  router-id = "192.168.0.1"
  as = 65000

[[neighbors]]
  [neighbors.config]
    neighbor-address = "192.168.10.2"
    peer-as = 65000
  [neighbors.route-reflector.config]
    route-reflector-client = true
    route-reflector-cluster-id = "192.168.0.1"

[[neighbors]]
  [neighbors.config]
    neighbor-address = "192.168.10.3"
    peer-as = 65000
  [neighbors.route-reflector.config]
    route-reflector-client = true
    route-reflector-cluster-id = "192.168.0.1"

[[neighbors]]
  [neighbors.config]
    neighbor-address = "192.168.10.4"
    peer-as = 65000

[[neighbors]]
  [neighbors.config]
    neighbor-address = "192.168.10.5"
    peer-as = 65000

Check route reflector behavior

Let's check adj-rib-out of a route reflector client.

$ gobgp neighbor 192.168.10.2 adj-out
Network              Next Hop             AS_PATH              Attrs
10.0.2.0/24          192.168.10.3                              [{Origin: i} {Med: 0} {LocalPref: 100} {Originator: 192.168.0.3} {ClusterList: [192.168.0.1]}]
10.0.3.0/24          192.168.10.4                              [{Origin: i} {Med: 0} {LocalPref: 100} {Originator: 192.168.0.4} {ClusterList: [192.168.0.1]}]
10.0.4.0/24          192.168.10.5                              [{Origin: i} {Med: 0} {LocalPref: 100} {Originator: 192.168.0.5} {ClusterList: [192.168.0.1]}]

You can see the routes from other iBGP peers are reflected. Also Originator and ClusterList path attributes are added.

For the normal iBGP peer's adj-rib-out

$ gobgp neighbor 192.168.10.4 adj-out
Network              Next Hop             AS_PATH              Attrs
10.0.1.0/24          192.168.10.2                              [{Origin: i} {Med: 0} {LocalPref: 100}]
10.0.2.0/24          192.168.10.3                              [{Origin: i} {Med: 0} {LocalPref: 100}]

Only the routes from route reflector clients are advertised via GoBGP. Originator and ClusterList path attributes are not added.