diff --git a/doc/bird.sgml b/doc/bird.sgml
index d1d2bdae..4d1db33f 100644
--- a/doc/bird.sgml
+++ b/doc/bird.sgml
@@ -252,16 +252,9 @@ The global best route selection algorithm is (roughly) as follows:
Usually, a routing table just chooses a selected
-route from a list of entries for one network. But if the table option for details.
Routes and network types
@@ -628,18 +621,73 @@ include "tablename.conf";;
- Create a new routing table. The default routing tables
- description for details.
+
+ Define a new routing table. The default routing tables for routing table options.
eval
Evaluates given filter expression. It is used by the developers for testing of filters.
+Routing table options
+
+
+Most routing tables do not need any options and are defined without an option
+block, but there are still some options to tweak routing table behavior. Note
+that implicit tables (
+ sorted
+ Usually, a routing table just chooses the selected (best) route from a
+ list of routes for each network, while keeping remaining routes unsorted.
+ If enabled, these lists of routes are kept completely sorted (according
+ to preference or some protocol-dependent metric).
+
+ This is needed for some protocol features (e.g. trie
+ BIRD routing tables are implemented with hash tables, which is efficient
+ for exact-match lookups, but inconvenient for longest-match lookups or
+ interval lookups (finding superprefix or subprefixes). This option
+ activates additional trie structure that is used to accelerate these
+ lookups, while using the hash table for exact-match lookups.
+
+ This has advantage for [ (on ROA tables),
+ for ][ (on IGP tables),
+ and is required for ][
+ (on base IP tables). Another advantage is that interval results (like
+ from ]min settle time
+ Specify a minimum value of the settle time. When a ROA table changes,
+ automatic [ may be
+ triggered, after a short settle time. Minimum settle time is a delay
+ from the last ROA table change to wait for more updates. Default: 1 s.
+
+
+ ]max settle time
+ Specify a maximum value of the settle time. When a ROA table changes,
+ automatic [ may be
+ triggered, after a short settle time. Maximum settle time is an upper
+ limit to the settle time from the initial ROA table change even if
+ there are consecutive updates gradually renewing the settle time.
+ Default: 20 s.
+
+
+
]Protocol options