Add explanation about the attribute "delay"

The libvirt created linux bridge has a configurable value "delay",
the default value is "0", but it will not take effect. That's because
kernel has a minimum value for linux bridge. Add some explanation
about it in the document.

Signed-off-by: Yalan Zhang <yalzhang@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

diff --git a/docs/formatnetwork.rst b/docs/formatnetwork.rst
index 5335da5e117ab7a5a8746efbb8a426b15e3a6c21..809e84248789d24cbb0f0fb4d0d235f680aeef54 100644 (file)
--- a/docs/formatnetwork.rst
+++ b/docs/formatnetwork.rst
@@ -106,7 +106,8 @@ to the physical LAN (if at all).
    prefix "virbr" is recommended (and that is what is auto-generated), but not
    enforced. Attribute ``stp`` specifies if Spanning Tree Protocol is 'on' or
    'off' (default is 'on'). Attribute ``delay`` sets the bridge's forward delay
-   value in seconds (default is 0). :since:`Since 0.3.0`
+   value in seconds (default is 0. As the kernel has a minimum delay, values
+   below it may not be counted). :since:`Since 0.3.0`
 
    The ``macTableManager`` attribute of the bridge element is used to tell
    libvirt how the bridge's MAC address table (used to determine the correct