+.IP "\fIdpname\fR \fIodp_flow\fR"
+\fIodp_flow\fR is a flow in the form printed by \fBovs\-dpctl\fR(8)'s
+\fBdump\-flows\fR command. If all of your bridges have the same type,
+which is the common case, then you can omit \fIdpname\fR, but if you
+have bridges of different types (say, both \fBovs-netdev\fR and
+\fBovs-system\fR), then you need to specify a \fIdpname\fR to disambiguate.
+.
+.IP "\fIbridge\fR \fIbr_flow\fR"
+\fIbr_flow\fR is a flow in the form similar to that accepted by
+\fBovs\-ofctl\fR(8)'s \fBadd\-flow\fR command. (This is not an
+OpenFlow flow: besides other differences, it never contains
+wildcards.) \fIbridge\fR names of the bridge through which
+\fIbr_flow\fR should be traced.
+.RE
+.
+.IP
+Most commonly, one specifies only a flow, using one of the forms
+above, but sometimes one might need to specify an actual packet
+instead of just a flow:
+.
+.RS
+.IP "Side effects."
+Some actions have side effects. For example, the \fBnormal\fR action
+can update the MAC learning table, and the \fBlearn\fR action can
+change OpenFlow tables. The trace commands only perform side
+effects when a packet is specified. If you want side effects to take
+place, then you must supply a packet.
+.
+.IP
+(Output actions are obviously side effects too, but
+the trace commands never execute them, even when one specifies a
+packet.)
+.
+.IP "Incomplete information."
+Most of the time, Open vSwitch can figure out everything about the
+path of a packet using just the flow, but in some special
+circumstances it needs to look at parts of the packet that are not
+included in the flow. When this is the case, and you do not supply a
+packet, then a trace command will tell you it needs a packet.
+.RE
+.
+.IP
+If you wish to include a packet as part of a trace operation, there
+are two ways to do it:
+.
+.RS
+.IP \fB\-generate\fR
+This option, added to one of the ways to specify a flow already
+described, causes Open vSwitch to internally generate a packet with
+the flow described and then to use that packet. If your goal is to
+execute side effects, then \fB\-generate\fR is the easiest way to do
+it, but \fB\-generate\fR is not a good way to fill in incomplete
+information, because it generates packets based on only the flow
+information, which means that the packets really do not have any more
+information than the flow.
+.
+.IP \fIpacket\fR
+This form supplies an explicit \fIpacket\fR as a sequence of hex
+digits. An Ethernet frame is at least 14 bytes long, so there must be
+at least 28 hex digits. Obviously, it is inconvenient to type in the
+hex digits by hand, so the \fBovs\-pcap\fR(1) and
+\fBovs\-tcpundump\fR(1) utilities provide easier ways.
+.IP
+With this form, packet headers are extracted directly from
+\fIpacket\fR, so the \fIodp_flow\fR or \fIbr_flow\fR should specify
+only metadata. The metadata can be:
+.RS
+.IP \fIskb_priority\fR
+Packet QoS priority.
+.IP \fIpkt_mark\fR
+Mark of the packet.
+.IP \fIct_state\fR
+Connection state of the packet.
+.IP \fIct_zone\fR
+Connection tracking zone for packet.
+.IP \fIct_mark\fR
+Connection mark of the packet.
+.IP \fIct_label\fR
+Connection label of the packet.
+.IP \fItun_id\fR
+The tunnel ID on which the packet arrived.
+.IP \fIin_port\fR
+The port on which the packet arrived.
+.RE
+.RE
+.
+.IP
+The in_port value is kernel datapath port number for the first format
+and OpenFlow port number for the second format. The numbering of these
+two types of port usually differs and there is no relationship.
+.
+.IP
+\fBofproto\-trace\-packet\-out\fR accepts an additional
+\fB\-consistent\fR option. With this option specified, the command
+rejects \fIactions\fR that are inconsistent with the specified packet.
+(An example of an inconsistency is attempting to strip the VLAN tag
+from a packet that does not have a VLAN tag.) Open vSwitch ignores
+most forms of inconsistency in OpenFlow 1.0 and rejects
+inconsistencies in later versions of OpenFlow. The option is
+necessary because the command does not ordinarily imply a particular
+OpenFlow version. One exception is that, when \fIactions\fR includes
+an action that only OpenFlow 1.1 and later supports (such as
+\fBpush_vlan\fR), \fB\-consistent\fR is automatically enabled.
+.IP "\fBofproto/self\-check\fR [\fIswitch\fR]"
+Runs an internal consistency check on \fIswitch\fR, if specified,
+otherwise on all ofproto instances, and responds with a brief summary
+of the results. If the summary reports any errors, then the Open
+vSwitch logs should contain more detailed information. Please pass
+along errors reported by this command to the Open vSwitch developers
+as bugs.
projects / cascardo / ovs.git / blobdiff