Doc: Documentation for long-lived graceful restart

diff --git a/doc/bird.sgml b/doc/bird.sgml
index 184c9e46df4718cca6137d37cd46219e2b18f052..c66e8c72583bf0a7f3a5a35fda650dbb74075b7b 100644 (file)
--- a/doc/bird.sgml
+++ b/doc/bird.sgml
@@ -2108,6 +2108,25 @@ using the following configuration parameters:
        re-establish after a restart before deleting stale routes. Default:
        120 seconds.
 
+       <tag><label id="bgp-long-lived-graceful-restart">long lived graceful restart <m/switch/|aware</tag>
+       The long-lived graceful restart is an extension of the traditional
+       <ref id="bgp-graceful-restart" name="BGP graceful restart">, where stale
+       routes are kept even after the <ref id="bgp-graceful-restart-time"
+       name="restart time"> expires for additional long-lived stale time, but
+       they are marked with the LLGR_STALE community, depreferenced, and
+       withdrawn from routers not supporting LLGR. Like traditional BGP
+       graceful restart, it has three states: disabled, aware (receiving-only),
+       and enabled. Note that long-lived graceful restart requires at least
+       aware level of traditional BGP graceful restart. Default: aware, unless
+       graceful restart is disabled.
+
+       <tag><label id="bgp-long-lived-stale-time">long lived stale time <m/number/</tag>
+       The long-lived stale time is announced in the BGP long-lived graceful
+       restart capability and specifies how long the neighbor would keep stale
+       routes depreferenced during long-lived graceful restart until either the
+       session is re-stablished and synchronized or the stale time expires and
+       routes are removed. Default: 3600 seconds.
+
        <tag><label id="bgp-interpret-communities">interpret communities <m/switch/</tag>
        <rfc id="1997"> demands that BGP speaker should process well-known
        communities like no-export (65535, 65281) or no-advertise (65535,