doc: add doc for bgp maximum-prefix knob

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>

diff --git a/doc/user/bgp.rst b/doc/user/bgp.rst
index 35e42d95cb5176038a9e69dafb2c324df04bf315..d663b4fc10f920c979ff2b2fa5d9664bf8503568 100644 (file)
--- a/doc/user/bgp.rst
+++ b/doc/user/bgp.rst
@@ -942,14 +942,18 @@ Configuring Peers
 .. index:: [no] neighbor PEER maximum-prefix NUMBER
 .. clicmd:: [no] neighbor PEER maximum-prefix NUMBER
 
-.. index:: [no] neighbor PEER local-as AS-NUMBER no-prepend
-.. clicmd:: [no] neighbor PEER local-as AS-NUMBER no-prepend
-
-.. index:: [no] neighbor PEER local-as AS-NUMBER no-prepend replace-as
-.. clicmd:: [no] neighbor PEER local-as AS-NUMBER no-prepend replace-as
-
-.. index:: [no] neighbor PEER local-as AS-NUMBER
-.. clicmd:: [no] neighbor PEER local-as AS-NUMBER
+   Sets a maximum number of prefixes we can receive from a given peer. If this
+   number is exceeded, the BGP session will be destroyed.
+
+   In practice, it is generally preferable to use a prefix-list to limit what
+   prefixes are received from the peer instead of using this knob. Tearing down
+   the BGP session when a limit is exceeded is far more destructive than merely
+   rejecting undesired prefixes. The prefix-list method is also much more
+   granular and offers much smarter matching criterion than number of received
+   prefixes, making it more suited to implementing policy.
+
+.. index:: [no] neighbor PEER local-as AS-NUMBER [no-prepend] [replace-as]
+.. clicmd:: [no] neighbor PEER local-as AS-NUMBER [no-prepend] [replace-as]
 
    Specify an alternate AS for this BGP process when interacting with the
    specified peer. With no modifiers, the specified local-as is prepended to