Merge pull request #2329 from pguibert6WIND/issue_2275_proposal

doc: inform the diff between config from zebra and outside

1 files changed, 26 insertions, 4 deletions

diff --git a/doc/user/zebra.rst b/doc/user/zebra.rst
index 9e377330ee..b6060f0737 100644
--- a/doc/user/zebra.rst
+++ b/doc/user/zebra.rst
@@ -58,6 +58,26 @@ Besides the common invocation options (:ref:`common-invocation-options`), the
 
 .. _interface-commands:
 
+Configuration Addresses behaviour
+=================================
+
+At startup, *Zebra* will first discover the underlying networking objects
+from the operating system. This includes interfaces, addresses of
+interfaces, static routes, etc. Then, it will read the configuration
+file, including its own interface addresses, static routes, etc. All this
+information comprises the operational context from *Zebra*. But
+configuration context from *Zebra* will remain the same as the one from
+:file:`zebra.conf` config file. As an example, executing the following
+:clicmd:`show running-config` will reflect what was in :file:`zebra.conf`.
+In a similar way, networking objects that are configured outside of the
+*Zebra* like *iproute2* will not impact the configuration context from
+*Zebra*. This behaviour permits you to continue saving your own config
+file, and decide what is really to be pushed on the config file, and what
+is dependent on the underlying system.
+Note that inversely, from *Zebra*, you will not be able to delete networking
+objects that were previously configured outside of *Zebra*.
+
+
 Interface Commands
 ==================
 
@@ -444,8 +464,9 @@ commands in relationship to VRF. Here is an extract of some of those commands:
 
    This command is available on configuration mode. By default, above command
    permits accessing the vrf configuration mode. This mode is available for
-   both VRFs. It is to be noted that *Zebra* does not create *Linux VRF*.
-   Provisioning this command is used to keep the configuration intact.
+   both VRFs. It is to be noted that *Zebra* does not create Linux VRF.
+   The network administrator can however decide to provision this command in
+   configuration file to provide more clarity about the intended configuration.
 
 .. index:: netns NAMESPACE
 .. clicmd:: netns NAMESPACE
@@ -454,8 +475,9 @@ commands in relationship to VRF. Here is an extract of some of those commands:
    when *Zebra* is run in :option:`-n` mode. This command reflects which *Linux
    network namespace* is to be mapped with *Zebra* VRF. It is to be noted that
    *Zebra* creates and detects added/suppressed VRFs from the Linux environment
-   (in fact, those managed with iproute2). Provisioning this command is used to
-   keep the configuration intact.
+   (in fact, those managed with iproute2). The network administrator can however
+   decide to provision this command in configuration file to provide more clarity
+   about the intended configuration.
 
 .. index:: ip route NETWORK NETMASK GATEWAY NEXTHOPVRF
 .. clicmd:: ip route NETWORK NETMASK GATEWAY NEXTHOPVRF