+ These columns are mutually exclusive. Exactly one of them must be
+ nonempty.
+
+
- Output port for selected packets, if nonempty. Mutually exclusive
- with .
+ Output port for selected packets, if nonempty.
Specifying a port for mirror output reserves that port exclusively
- for mirroring. No frames other than those selected for mirroring
- will be forwarded to the port, and any frames received on the port
- will be discarded.
- This type of mirroring is sometimes called SPAN.
+ for mirroring. No frames other than those selected for mirroring
+ will be forwarded to the port, and any frames received on the port
+ will be discarded.
+
+ The output port may be any kind of port supported by Open vSwitch.
+ It may be, for example, a physical port (sometimes called SPAN), or a
+ GRE tunnel (sometimes called ERSPAN).
+
- Output VLAN for selected packets, if nonempty. Mutually exclusive
- with .
+ Output VLAN for selected packets, if nonempty.
The frames will be sent out all ports that trunk
, as well as any ports with implicit VLAN
. When a mirrored frame is sent out a
@@ -1134,6 +1737,37 @@
, replacing any existing tag; when it is
sent out an implicit VLAN port, the frame will not be tagged. This
type of mirroring is sometimes called RSPAN.
+
+ The following destination MAC addresses will not be mirrored to a
+ VLAN to avoid confusing switches that interpret the protocols that
+ they represent:
+
+
+ 01:80:c2:00:00:00
+ - IEEE 802.1D Spanning Tree Protocol (STP).
+
+ 01:80:c2:00:00:01
+ - IEEE Pause frame.
+
+ 01:80:c2:00:00:0x
+ - Other reserved protocols.
+
+ 01:00:0c:cc:cc:cc
+ -
+ Cisco Discovery Protocol (CDP), VLAN Trunking Protocol (VTP),
+ Dynamic Trunking Protocol (DTP), Port Aggregation Protocol (PAgP),
+ and others.
+
+
+ 01:00:0c:cc:cc:cd
+ - Cisco Shared Spanning Tree Protocol PVSTP+.
+
+ 01:00:0c:cd:cd:cd
+ - Cisco STP Uplink Fast.
+
+ 01:00:0c:00:00:00
+ - Cisco Inter Switch Link.
+
Please note: Mirroring to a VLAN can disrupt a network that
contains unmanaged switches. Consider an unmanaged physical switch
with two ports: port 1, connected to an end host, and port 2,
@@ -1159,6 +1793,10 @@
Open vSwitch is being used as an intermediate switch, learning can be
disabled by adding the mirrored VLAN to
in the appropriate table or tables.
+
+ Mirroring to a GRE tunnel has fewer caveats than mirroring to a
+ VLAN and should generally be preferred.
+