bonding: T2877: support configuration of minimum number of active links

Specifies the minimum number of links that must be active before asserting
carrier. It is similar to the Cisco EtherChannel min-links feature. This allows
setting the minimum number of member ports that must be up (link-up state)
before marking the bond device as up (carrier on). This is useful for situations
where higher level services such as clustering want to ensure a minimum number
of low bandwidth links are active before switchover.

This option only affects 802.3ad mode.

The default value is 0. This will cause carrier to be asserted (for 802.3ad
mode) whenever there is an active aggregator, regardless of the number of
available links in that aggregator. Note that, because an aggregator cannot be
active without at least one available link, setting this option to 0 or to 1
has the exact same effect.

1 files changed, 13 insertions, 0 deletions

diff --git a/interface-definitions/interfaces-bonding.xml.in b/interface-definitions/interfaces-bonding.xml.in
index 7d658f6a0..b28be387b 100644
--- a/interface-definitions/interfaces-bonding.xml.in
+++ b/interface-definitions/interfaces-bonding.xml.in
@@ -99,6 +99,19 @@
             </children>
           </node>
           #include <include/interface-mac.xml.i>
+          <leafNode name="min-links">
+            <properties>
+              <help>Minimum number of member interfaces required up before enabling bond</help>
+              <valueHelp>
+                <format>&lt;0-16&gt;</format>
+                <description>Minimum number of member interfaces required up before enabling bond</description>
+              </valueHelp>
+              <constraint>
+                <validator name="numeric" argument="--range 0-16"/>
+              </constraint>
+            </properties>
+            <defaultValue>0</defaultValue>
+          </leafNode>
           <leafNode name="mode">
             <properties>
               <help>Bonding mode</help>