1 files changed, 13 insertions, 8 deletions

diff --git a/doc/bird.sgml b/doc/bird.sgml
index 3edd6e0e..820ebaa2 100644
--- a/doc/bird.sgml
+++ b/doc/bird.sgml
@@ -1811,7 +1811,7 @@ protocol ospf <name> {
 			summary <switch>;
 			cost <num>;
 		}
-		interface <interface pattern> {
+		interface <interface pattern> [instance <num>] {
 			cost <num>;
 			stub <switch>;
 			hello <num>;
@@ -1841,7 +1841,7 @@ protocol ospf <name> {
 				<ip> eligible;
 			};
 		};
-		virtual link <id>	{
+		virtual link <id> [instance <num>] {
 			hello <num>;
 			retransmit <num>;
 			wait <num>;
@@ -1961,14 +1961,19 @@ protocol ospf <name> {
 	 subnetworks of given stub network are suppressed. This might
 	 be used, for example, to aggregate generated stub networks.
 	 
-	<tag>interface <M>pattern</M></tag>
+	<tag>interface <M>pattern</M> [instance <m/num/]</tag>
 	 Defines that the specified interfaces belong to the area being defined.
 	 See <ref id="dsc-iface" name="interface"> common option for detailed description.
-
-	<tag>virtual link <M>id</M></tag>
-	 Virtual link to router with the router id. Virtual link acts as a
-         point-to-point interface belonging to backbone. The actual area is
-         used as transport area. This item cannot be in the backbone.
+	 In OSPFv3, you can specify instance ID for that interface
+	 description, so it is possible to have several instances of
+	 that interface with different options or even in different areas.
+
+	<tag>virtual link <M>id</M> [instance <m/num/]</tag>
+	 Virtual link to router with the router id. Virtual link acts
+         as a point-to-point interface belonging to backbone. The
+         actual area is used as transport area. This item cannot be in
+         the backbone. In OSPFv3, you could also use several virtual
+         links to one destination with different instance IDs.
 
 	<tag>cost <M>num</M></tag>
 	 Specifies output cost (metric) of an interface. Default value is 10.