basic network reload documentation

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

diff --git a/pve-network.adoc b/pve-network.adoc
index 3703dcafc28359640125f22c361f5016b34bd666..c61cd42e7e923bfe074b30a5e28a90961a4b82d5 100644 (file)
--- a/pve-network.adoc
+++ b/pve-network.adoc
@@ -9,16 +9,55 @@ Network configuration can be done either via the GUI, or by manually
 editing the file `/etc/network/interfaces`, which contains the
 whole network configuration. The  `interfaces(5)` manual page contains the
 complete format description. All {pve} tools try hard to keep direct
- user modifications, but using the GUI is still preferable, because it
+user modifications, but using the GUI is still preferable, because it
 protects you from errors.
 
 Once the network is configured, you can use the Debian traditional tools `ifup`
 and `ifdown` commands to bring interfaces up and down.
 
-NOTE: {pve} does not write changes directly to
-`/etc/network/interfaces`. Instead, we write into a temporary file
-called `/etc/network/interfaces.new`, and commit those changes when
-you reboot the node.
+Apply Network Changes
+~~~~~~~~~~~~~~~~~~~~~
+
+{pve} does not write changes directly to `/etc/network/interfaces`. Instead, we
+write into a temporary file called `/etc/network/interfaces.new`, this way you
+can do many related changes at once. This also allows to ensure your changes
+are correct before applying, as a wrong network configuration may render a node
+inaccessible.
+
+Reboot Node to apply
+^^^^^^^^^^^^^^^^^^^^
+
+With the default installed `ifupdown` network managing package you need to
+reboot to commit any pending network changes. Most of the time, the basic {pve}
+network setup is stable and does not change often, so rebooting should not be
+required often.
+
+Reload Network with ifupdown2
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+With the optional `ifupdown2` network managing package you also can reload the
+network configuration live, without requiring a reboot.
+
+NOTE: 'ifupdown2' cannot understand 'OpenVSwitch' syntax, so reloading is *not*
+possible if OVS interfaces are configured.
+
+Since {pve} 6.1 you can apply pending network changes over the web-interface,
+using the 'Apply Configuration' button in the 'Network' panel of a node.
+
+To install 'ifupdown2' ensure you have the latest {pve} updates installed, then
+
+WARNING: installing 'ifupdown2' will remove 'ifupdown', but as the removal
+scripts of 'ifupdown' before version '0.8.35+pve1' have a issue where network
+is fully stopped on removal footnote:[Introduced with Debian Buster:
+https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=945877] you *must* ensure
+that you have a up to date 'ifupdown' package version.
+
+For the installation itself you can then simply do:
+
+ apt install ifupdown2
+
+With that you're all set. You can also switch back to the 'ifupdown' variant at
+any time, if you run into issues.
 
 Naming Conventions
 ~~~~~~~~~~~~~~~~~~