doc: Add redistribute vnc-direct command

[mirror_frr.git] / doc / user / bgp.rst

diff --git a/doc/user/bgp.rst b/doc/user/bgp.rst
index be331ffb99577f7c680bbf97fccbff729c9e7b83..0e9decb090d24a72e00746cc533d6772efd74ca1 100644 (file)
--- a/doc/user/bgp.rst
+++ b/doc/user/bgp.rst
@@ -391,6 +391,16 @@ Administrative Distance Metrics
 
    Sets the administrative distance for a particular route.
 
+.. _bgp-requires-policy:
+
+Require policy on EBGP
+-------------------------------
+
+.. index:: [no] bgp ebgp-requires-policy
+.. clicmd:: [no] bgp ebgp-requires-policy
+
+   This command requires incoming and outgoing filters to be applied for eBGP sessions. Without the incoming filter, no routes will be accepted. Without the outgoing filter, no routes will be announced.
+
 .. _bgp-route-flap-dampening:
 
 Route Flap Dampening
@@ -738,11 +748,16 @@ Redistribution
 
    Redistribute OSPF route to BGP process.
 
-.. index:: redistribute vpn
-.. clicmd:: redistribute vpn
+.. index:: redistribute vnc
+.. clicmd:: redistribute vnc
 
    Redistribute VNC routes to BGP process.
 
+.. index:: redistribute vnc-direct
+.. clicmd:: redistribute vnc-direct
+
+   Redistribute VNC direct (not via zebra) routes to BGP process.
+
 .. index:: update-delay MAX-DELAY
 .. clicmd:: update-delay MAX-DELAY
 
@@ -826,6 +841,30 @@ Defining Peers
    peers ASN is the same as mine as specified under the :clicmd:`router bgp ASN`
    command the connection will be denied.
 
+.. index:: [no] bgp listen range <A.B.C.D/M|X:X::X:X/M> peer-group PGNAME
+.. clicmd:: [no] bgp listen range <A.B.C.D/M|X:X::X:X/M> peer-group PGNAME
+
+   Accept connections from any peers in the specified prefix. Configuration
+   from the specified peer-group is used to configure these peers.
+
+.. note::
+
+   When using BGP listen ranges, if the associated peer group has TCP MD5
+   authentication configured, your kernel must support this on prefixes. On
+   Linux, this support was added in kernel version 4.14. If your kernel does
+   not support this feature you will get a warning in the log file, and the
+   listen range will only accept connections from peers without MD5 configured.
+
+   Additionally, we have observed that when using this option at scale (several
+   hundred peers) the kernel may hit its option memory limit. In this situation
+   you will see error messages like:
+
+   ``bgpd: sockopt_tcp_signature: setsockopt(23): Cannot allocate memory``
+
+   In this case you need to increase the value of the sysctl
+   ``net.core.optmem_max`` to allow the kernel to allocate the necessary option
+   memory.
+
 .. _bgp-configuring-peers:
 
 Configuring Peers
@@ -918,14 +957,18 @@ 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
+   Sets a maximum number of prefixes we can receive from a given peer. If this
+   number is exceeded, the BGP session will be destroyed.
 
-.. index:: [no] neighbor PEER local-as AS-NUMBER no-prepend replace-as
-.. clicmd:: [no] neighbor PEER local-as AS-NUMBER no-prepend replace-as
+   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
-.. clicmd:: [no] neighbor PEER local-as AS-NUMBER
+.. 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
@@ -1022,8 +1065,8 @@ and will share updates.
 
    This command defines a new peer group.
 
-.. index:: neighbor PEER peer-group WORD
-.. clicmd:: neighbor PEER peer-group WORD
+.. index:: neighbor PEER peer-group PGNAME
+.. clicmd:: neighbor PEER peer-group PGNAME
 
    This command bind specific peer to peer group WORD.
 
@@ -1103,19 +1146,24 @@ AS path access list is user defined AS path.
 Using AS Path in Route Map
 --------------------------
 
-.. index:: match as-path WORD
-.. clicmd:: match as-path WORD
+.. index:: [no] match as-path WORD
+.. clicmd:: [no] match as-path WORD
 
+   For a given as-path, WORD, match it on the BGP as-path given for the prefix
+   and if it matches do normal route-map actions.  The no form of the command
+   removes this match from the route-map.
 
-.. index:: set as-path prepend AS-PATH
-.. clicmd:: set as-path prepend AS-PATH
+.. index:: [no] set as-path prepend AS-PATH
+.. clicmd:: [no] set as-path prepend AS-PATH
 
-   Prepend the given string of AS numbers to the AS_PATH.
+   Prepend the given string of AS numbers to the AS_PATH of the BGP path's NLRI.
+   The no form of this command removes this set operation from the route-map.
 
-.. index:: set as-path prepend last-as NUM
-.. clicmd:: set as-path prepend last-as NUM
+.. index:: [no] set as-path prepend last-as NUM
+.. clicmd:: [no] set as-path prepend last-as NUM
 
    Prepend the existing last AS number (the leftmost ASN) to the AS_PATH.
+   The no form of this command removes this set operation from the route-map.
 
 .. _bgp-communities-attribute: