gre: Don't require incoming checksum.

[openvswitch] / vswitchd / vswitch.xml

diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml
index 465f27dd1b2a0df279f98a42f45298f687f82ad8..ce1c7140740631e90b996ce028b03ac729b04f0c 100644 (file)
--- a/vswitchd/vswitch.xml
+++ b/vswitchd/vswitch.xml
@@ -442,7 +442,7 @@
           <dt><code>tap</code></dt>
           <dd>A TUN/TAP device managed by Open vSwitch.</dd>
           <dt><code>gre</code></dt>
-          <dd>An Ethernet over RFC 1702 Generic Routing Encapsulation over IPv4
+          <dd>An Ethernet over RFC 2890 Generic Routing Encapsulation over IPv4
              tunnel.  Each tunnel must be uniquely identified by the
              combination of <code>remote_ip</code>, <code>local_ip</code>, and
              <code>in_key</code>.  Note that if two ports are defined that are
@@ -477,7 +477,7 @@
                 either be a 32-bit number or the word <code>flow</code>.  If
                 <code>flow</code> is specified then the key may be set using
                 the <code>set_tunnel</code> Nicira OpenFlow vendor extension (0
-                is used in the absense of an action).  The ovs-ofctl manual
+                is used in the absence of an action).  The ovs-ofctl manual
                 page contains additional information about the Nicira OpenFlow
                 vendor extensions.  Default is no key.</dd>
             </dl>
@@ -505,9 +505,14 @@
             </dl>
             <dl>
               <dt><code>csum</code></dt>
-              <dd>Optional.  Compute GRE checksums for outgoing packets and
-                require checksums for incoming packets.  Default is enabled,
-                set to <code>false</code> to disable.</dd>
+              <dd>Optional.  Compute GRE checksums on outgoing packets.
+                Checksums present on incoming packets will be validated
+                regardless of this setting.  Note that GRE checksums
+                impose a significant performance penalty as they cover the
+                entire packet.  As the contents of the packet is typically
+                covered by L3 and L4 checksums, this additional checksum only
+                adds value for the GRE and encapsulated Ethernet headers.
+                Default is disabled, set to <code>true</code> to enable.</dd>
             </dl>
             <dl>
               <dt><code>pmtud</code></dt>