doc: Add `neighbor PEER extended-optional-parameters` command

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>
(cherry picked from commit 13111667513a0f91a8e875cdf12c940ea2b60b05)

diff --git a/doc/user/bgp.rst b/doc/user/bgp.rst
index 476c06aed487517f0a56a956cbcff227498e90bb..85fa33721698effae213487f9d88187117e080cb 100644 (file)
--- a/doc/user/bgp.rst
+++ b/doc/user/bgp.rst
@@ -1746,6 +1746,15 @@ Configuring Peers
    default, the DelayOpenTimer is disabled. The timer interval may be set to a
    duration of 1 to 240 seconds.
 
+.. clicmd:: neighbor PEER extended-optional-parameters
+
+   Force the extended optional parameters format for OPEN messages. By default,
+   optional parameters length is 255 octets. With more and more BGP capabilities
+   implemented on top of BGP, this is needed to extend this value.
+
+   This is turned off by default, but it's automatically enabled when this limit
+   is hit. You can force this new encoding to be enabled with this command.
+
 .. clicmd:: bgp minimum-holdtime (1-65535)
 
    This command allows user to prevent session establishment with BGP peers