BGP: Enhanced route refresh (RFC 7313) support

Also hook feed_done is renamed to feed_end.

1 files changed, 11 insertions, 7 deletions

diff --git a/doc/bird.sgml b/doc/bird.sgml
index bcf1c8fb..fc5fc9ae 100644
--- a/doc/bird.sgml
+++ b/doc/bird.sgml
@@ -1804,13 +1804,17 @@ using the following configuration parameters:
 	other means. Default: 0 (no local AS number allowed).
 
 	<tag>enable route refresh <m/switch/</tag>
-	When BGP speaker changes its import filter, it has to re-examine all
-	routes received from its neighbor against the new filter. As these
-	routes might not be available, there is a BGP protocol extension Route
-	Refresh (specified in RFC 2918) that allows BGP speaker to request
-	re-advertisement of all routes from its neighbor. This option specifies
-	whether BIRD advertises this capability and accepts such requests. Even
-	when disabled, BIRD can send route refresh requests. Default: on.
+	After the initial route exchange, BGP protocol uses incremental updates
+	to keep BGP speakers synchronized. Sometimes (e.g., if BGP speaker
+	changes its import filter, or if there is suspicion of inconsistency) it
+	is necessary to do a new complete route exchange. BGP protocol extension
+	Route Refresh (RFC 2918) allows BGP speaker to request re-advertisement
+	of all routes from its neighbor. BGP protocol extension Enhanced Route
+	Refresh (RFC 7313) specifies explicit begin and end for such exchanges,
+	therefore the receiver can remove stale routes that were not advertised
+	during the exchange. This option specifies whether BIRD advertises these
+	capabilities and supports related procedures. Note that even when
+	disabled, BIRD can send route refresh requests. Default: on.
 
 	<tag>graceful restart <m/switch/|aware</tag>
 	When a BGP speaker restarts or crashes, neighbors will discard all