docs: add route-reflector document

Signed-off-by: ISHIDA Wataru <ishida.wataru@lab.ntt.co.jp>

1 files changed, 69 insertions, 0 deletions

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+# Route Reflector
+
+This page explains how to set up GoBGP as a route reflector.
+
+## Prerequisites
+
+Assumed you finished [Getting Started](https://github.com/osrg/gobgp/blob/master/docs/sources/getting-started.md).
+
+## Configuration
+
+Configure `RouteReflector.RouteReflectorConfig` section to enable route reflector functionality.
+The configuration below configures two route reflector clients and two normal iBGP peers.
+
+```toml
+[Global]
+  [Global.GlobalConfig]
+    RouterId = "192.168.0.1"
+    As = 65000
+[Neighbors]
+  [[Neighbors.NeighborList]]
+    [Neighbors.NeighborList.NeighborConfig]
+      NeighborAddress = "192.168.10.2"
+      PeerAs = 65000
+    [Neighbors.NeighborList.RouteReflector.RouteReflectorConfig]
+      RouteReflectorClient = true
+      RouteReflectorClusterId = "192.168.0.1"
+  [[Neighbors.NeighborList]]
+    [Neighbors.NeighborList.NeighborConfig]
+      NeighborAddress = "192.168.10.3"
+      PeerAs = 65000
+    [Neighbors.NeighborList.RouteReflector.RouteReflectorConfig]
+      RouteReflectorClient = true
+      RouteReflectorClusterId = "192.168.0.1"
+  [[Neighbors.NeighborList]]
+    [Neighbors.NeighborList.NeighborConfig]
+      NeighborAddress = "192.168.10.4"
+      PeerAs = 65000
+  [[Neighbors.NeighborList]]
+    [Neighbors.NeighborList.NeighborConfig]
+      NeighborAddress = "192.168.10.5"
+      PeerAs = 65000
+```
+
+## Check route reflector behavior
+
+Let's check adj-rib-out of a route reflector client.
+
+```bash
+$ 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
+
+```bash
+$ 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.