doc: describe Rx bytes counter behavior for enic

Signed-off-by: Hyong Youb Kim <hyonkim@cisco.com>
Reviewed-by: John Daley <johndale@cisco.com>

diff --git a/doc/guides/nics/enic.rst b/doc/guides/nics/enic.rst
index 7e19cf8..0bc5593 100644 (file)
--- a/doc/guides/nics/enic.rst
+++ b/doc/guides/nics/enic.rst
@@ -310,6 +310,14 @@ Limitations
     were added. Since there currently is no grouping or priority support,
     'catch-all' filters should be added last.
 
+- **Statistics**
+
+  - ``rx_good_bytes`` (ibytes) always includes VLAN header (4B) and CRC bytes (4B).
+  - When the NIC drops a packet because the Rx queue has no free buffers,
+    ``rx_good_bytes`` still increments by 4B if the packet is not VLAN tagged or
+    VLAN stripping is disabled, or by 8B if the packet is VLAN tagged and stripping
+    is enabled.
+
 How to build the suite
 ----------------------