From 773253559e914b08465cc4509612c1c8c55a8cf2 Mon Sep 17 00:00:00 2001
From: Maximilian Wilhelm <max@sdn.clinic>
Date: Sun, 24 Jun 2018 11:12:49 +0200
Subject: [PATCH] Annotate route selection process and add eBGP vs. iBGP tie
breaking.
Signed-off-by: Maximilian Wilhelm <max@sdn.clinic>
---
route/bgp_path.go | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/route/bgp_path.go b/route/bgp_path.go
index 0ab7dc4b..1f100024 100644
--- a/route/bgp_path.go
+++ b/route/bgp_path.go
@@ -40,6 +40,11 @@ func (b *BGPPath) Compare(c *BGPPath) int8 {
return -1
}
+ /*
+ * 9.1.2.2. Breaking Ties (Phase 2)
+ */
+
+ // a)
if c.ASPathLen > b.ASPathLen {
return 1
}
@@ -48,6 +53,7 @@ func (b *BGPPath) Compare(c *BGPPath) int8 {
return -1
}
+ // b)
if c.Origin > b.Origin {
return 1
}
@@ -56,6 +62,7 @@ func (b *BGPPath) Compare(c *BGPPath) int8 {
return -1
}
+ // c)
if c.MED > b.MED {
return 1
}
@@ -64,6 +71,18 @@ func (b *BGPPath) Compare(c *BGPPath) int8 {
return -1
}
+ // d)
+ if c.EBGP && !b.EBGP {
+ return -1
+ }
+
+ if !c.EBGP && b.EBGP {
+ return 1
+ }
+
+ // e) TODO: interiour cost (hello IS-IS and OSPF)
+
+ // f)
if c.BGPIdentifier < b.BGPIdentifier {
return 1
}
@@ -72,6 +91,7 @@ func (b *BGPPath) Compare(c *BGPPath) int8 {
return -1
}
+ // g)
if c.Source < b.Source {
return 1
}
--
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