bgp & bgp6: lower preference for ibgp

Prefer to go outside directly if possible

etc/local/bird/bird/bgp.conf

@@ -18,6 +18,7 @@ template bgp tpl_bgp {
 template bgp ibgp from tpl_bgp {
 	direct;
 	gateway direct;
+	preference 50;
 	local as 20766;
 	next hop self;
 	import where bgp_import(20766,"core",0,100);

etc/local/bird/bird6/bgp.conf

@@ -17,6 +17,7 @@ template bgp tpl_bgp {
 template bgp ibgp from tpl_bgp {
 	direct;
 	gateway direct;
+	preference 50;
 	local as 20766;
 	next hop self;
 	import where bgp_import(20766,"core",0,100);