The ovs-dpctl program can create, modify, and delete Open vSwitch
datapaths. A single machine may host any number of datapaths.
This program works only with datapaths that are implemented
outside of ovs-vswitchd itself, such as the Linux and Windows
kernel-based datapaths. To manage datapaths that are integrated
into ovs-vswitchd, such as the userspace (netdev) datapath, use
ovs-appctl(8) to invoke the dpctl/* commands, which are
documented in ovs-vswitchd(8).
A newly created datapath is associated with only one network
device, a virtual network device sometimes called the datapath's
``local port''. A newly created datapath is not, however,
associated with any of the host's other network devices. To
intercept and process traffic on a given network device, use the
add-if command to explicitly add that network device to the
datapath.
If ovs-vswitchd(8) is in use, use ovs-vsctl(8) instead of
ovs-dpctl.
Most ovs-dpctl commands that work with datapaths take an argument
that specifies the name of the datapath. Datapath names take the
form [type@]name, where name is the network device associated
with the datapath's local port. If type is given, it specifies
the datapath provider of name, otherwise the default provider
system is assumed.
The following commands manage datapaths. Do not use commands to
add or remove or modify datapaths if ovs-vswitchd is running
because this interferes with ovs-vswitchd's own datapath
management.
add-dp dp [netdev[,option]...]
Creates datapath dp, with a local port also named dp.
This will fail if a network device dp already exists.
If netdevs are specified, ovs-dpctl adds them to the new
datapath, just as if add-if was specified.
del-dp dp
Deletes datapath dp. If dp is associated with any network
devices, they are automatically removed.
add-if dp netdev[,option]...
Adds each netdev to the set of network devices datapath dp
monitors, where dp is the name of an existing datapath,
and netdev is the name of one of the host's network
devices, e.g. eth0. Once a network device has been added
to a datapath, the datapath has complete ownership of the
network device's traffic and the network device appears
silent to the rest of the system.
A netdev may be followed by a comma-separated list of
options. The following options are currently supported:
type=type
Specifies the type of port to add. The default
type is system.
port_no=port
Requests a specific port number within the
datapath. If this option is not specified then one
will be automatically assigned.
key=value
Adds an arbitrary key-value option to the port's
configuration.
ovs-vswitchd.conf.db(5) documents the available port types
and options.
set-if dp port[,option]...
Reconfigures each port in dp as specified. An option of
the form key=value adds the specified key-value option to
the port or overrides an existing key's value. An option
of the form key=, that is, without a value, deletes the
key-value named key. The type and port number of a port
cannot be changed, so type and port_no are only allowed if
they match the existing configuration.
del-if dp netdev...
Removes each netdev from the list of network devices
datapath dp monitors.
dump-dps
Prints the name of each configured datapath on a separate
line.
[-s | --statistics] show [dp...]
Prints a summary of configured datapaths, including their
datapath numbers and a list of ports connected to each
datapath. (The local port is identified as port 0.) If
-s or --statistics is specified, then packet and byte
counters are also printed for each port.
The datapath numbers consists of flow stats and mega flow
mask stats.
The "lookups" row displays three stats related to flow
lookup triggered by processing incoming packets in the
datapath. "hit" displays number of packets matches
existing flows. "missed" displays the number of packets
not matching any existing flow and require user space
processing. "lost" displays number of packets destined
for user space process but subsequently dropped before
reaching userspace. The sum of "hit" and "miss" equals to
the total number of packets datapath processed.
The "flows" row displays the number of flows in datapath.
The "masks" row displays the mega flow mask stats. This
row is omitted for datapath not implementing mega flow.
"hit" displays the total number of masks visited for
matching incoming packets. "total" displays number of
masks in the datapath. "hit/pkt" displays the average
number of masks visited per packet; the ratio between
"hit" and total number of packets processed by the
datapath.
If one or more datapaths are specified, information on
only those datapaths are displayed. Otherwise, ovs-dpctl
displays information about all configured datapaths.
DATAPATH FLOW TABLE DEBUGGING COMMANDS
The following commands are primarily useful for debugging Open
vSwitch. The flow table entries (both matches and actions) that
they work with are not OpenFlow flow entries. Instead, they are
different and considerably simpler flows maintained by the Open
vSwitch kernel module. Do not use commands to add or remove or
modify datapath flows if ovs-vswitchd is running because it
interferes with ovs-vswitchd's own datapath flow management. Use
ovs-ofctl(8), instead, to work with OpenFlow flow entries.
The dp argument to each of these commands is optional when
exactly one datapath exists, in which case that datapath is the
default. When multiple datapaths exist, then a datapath name is
required.
[-m | --more] [--names | --no-names] dump-flows [dp]
[filter=filter] [type=type] [pmd=pmd]
Prints to the console all flow entries in datapath dp's
flow table. Without -m or --more, output omits match
fields that a flow wildcards entirely; with -m or --more,
output includes all wildcarded fields.
If filter=filter is specified, only displays the flows
that match the filter. filter is a flow in the form
similiar to that accepted by ovs-ofctl(8)'s add-flow
command. (This is not an OpenFlow flow: besides other
differences, it never contains wildcards.) The filter is
also useful to match wildcarded fields in the datapath
flow. As an example, filter='tcp,tp_src=100' will match
the datapath flow containing
'tcp(src=80/0xff00,dst=8080/0xff)'.
If pmd=pmd is specified, only displays flows of the
specified pmd. Using pmd=-1 will restrict the dump to
flows from the main thread. This option is only supported
by the userspace datapath.
If type=type is specified, only displays flows of the
specified types. This option supported only for
ovs-appctl dpctl/dump-flows. type is a comma separated
list, which can contain any of the following:
ovs - displays flows handled in the ovs dp
tc - displays flows handled in the tc dp
dpdk - displays flows fully offloaded by dpdk
offloaded - displays flows offloaded to the HW
non-offloaded - displays flows not offloaded to the HW
partially-offloaded - displays flows where only part of
their proccessing is done in HW
all - displays all the types of flows
By default all the types of flows are displayed.
ovs-dpctl always acts as if the type was ovs.
add-flow [dp] flow actions
[--clear] [--may-create] [-s | --statistics] mod-flow [dp] flow
actions
Adds or modifies a flow in dp's flow table that, when a
packet matching flow arrives, causes actions to be
executed.
The add-flow command succeeds only if flow does not
already exist in dp. Contrariwise, mod-flow without
--may-create only modifies the actions for an existing
flow. With --may-create, mod-flow will add a new flow or
modify an existing one.
If -s or --statistics is specified, then mod-flow prints
the modified flow's statistics. A flow's statistics are
the number of packets and bytes that have passed through
the flow, the elapsed time since the flow last processed a
packet (if ever), and (for TCP flows) the union of the TCP
flags processed through the flow.
With --clear, mod-flow zeros out the flow's statistics.
The statistics printed if -s or --statistics is also
specified are those from just before clearing the
statistics.
NOTE: flow and actions do not match the syntax used with
ovs-ofctl(8)'s add-flow command.
Usage Examples
Forward ARP between ports 1 and 2 on datapath myDP:
ovs-dpctl add-flow myDP \
"in_port(1),eth(),eth_type(0x0806),arp()" 2
ovs-dpctl add-flow myDP \
"in_port(2),eth(),eth_type(0x0806),arp()" 1
Forward all IPv4 traffic between two addresses on ports 1
and 2:
ovs-dpctl add-flow myDP \
"in_port(1),eth(),eth_type(0x800),\
ipv4(src=172.31.110.4,dst=172.31.110.5)" 2
ovs-dpctl add-flow myDP \
"in_port(2),eth(),eth_type(0x800),\
ipv4(src=172.31.110.5,dst=172.31.110.4)" 1
add-flows [dp] file
mod-flows [dp] file
del-flows [dp] file
Reads flow entries from file (or stdin if file is -) and
adds, modifies, or deletes each entry to the datapath.
Each flow specification (e.g., each line in file) may
start with add, modify, or delete keyword to specify
whether a flow is to be added, modified, or deleted. A
flow specification without one of these keywords is
treated based on the used command. All flow modifications
are executed as individual transactions in the order
specified.
[-s | --statistics] del-flow [dp] flow
Deletes the flow from dp's flow table that matches flow.
If -s or --statistics is specified, then del-flow prints
the deleted flow's statistics.
[-m | --more] [--names | --no-names] get-flow [dp] ufid:ufid
Fetches the flow from dp's flow table with unique
identifier ufid. ufid must be specified as a string of 32
hexadecimal characters.
del-flows [dp]
Deletes all flow entries from datapath dp's flow table.
CONNECTION TRACKING TABLE COMMANDS
The following commands are useful for debugging and configuring
the connection tracking table in the datapath.
The dp argument to each of these commands is optional when
exactly one datapath exists, in which case that datapath is the
default. When multiple datapaths exist, then a datapath name is
required.
N.B.(Linux specific): the system datapaths (i.e. the Linux kernel
module Open vSwitch datapaths) share a single connection tracking
table (which is also used by other kernel subsystems, such as
iptables, nftables and the regular host stack). Therefore, the
following commands do not apply specifically to one datapath.
ipf-set-enabled [dp] v4|v6
ipf-set-disabled [dp] v4|v6
Enables or disables IP fragmentation handling for the
userspace connection tracker. Either v4 or v6 must be
specified. Both IPv4 and IPv6 fragment reassembly are
enabled by default. Only supported for the userspace
datapath.
ipf-set-min-frag [dp] v4|v6 minfrag
Sets the minimum fragment size (L3 header and data) for
non-final fragments to minfrag. Either v4 or v6 must be
specified. For enhanced DOS security, higher minimum
fragment sizes can usually be used. The default IPv4
value is 1200 and the clamped minimum is 400. The default
IPv6 value is 1280, with a clamped minimum of 400, for
testing flexibility. The maximum fragment size is not
clamped, however, setting this value too high might result
in valid fragments being dropped. Only supported for
userspace datapath.
ipf-set-max-nfrags [dp] maxfrags
Sets the maximum number of fragments tracked by the
userspace datapath connection tracker to maxfrags. The
default value is 1000 and the clamped maximum is 5000.
Note that packet buffers can be held by the fragmentation
module while fragments are incomplete, but will timeout
after 15 seconds. Memory pool sizing should be set
accordingly when fragmentation is enabled. Only supported
for userspace datapath.
[-m | --more] ipf-get-status [dp]
Gets the configuration settings and fragment counters
associated with the fragmentation handling of the
userspace datapath connection tracker. With -m or --more,
also dumps the IP fragment lists. Only supported for
userspace datapath.
[-m | --more] [-s | --statistics] dump-conntrack [dp] [zone=zone]
Prints to the console all the connection entries in the
tracker used by dp. If zone=zone is specified, only shows
the connections in zone. With --more, some implementation
specific details are included. With --statistics timeouts
and timestamps are added to the output.
flush-conntrack [dp] [zone=zone] [ct-tuple]
Flushes the connection entries in the tracker used by dp
based on zone and connection tracking tuple ct-tuple. If
ct-tuple is not provided, flushes all the connection
entries. If zone=zone is specified, only flushes the
connections in zone.
If ct-tuple is provided, flushes the connection entry
specified by ct-tuple in zone. The zone defaults to 0 if
it is not provided. The userspace connection tracker
requires flushing with the original pre-NATed tuple and a
warning log will be otherwise generated. An example of an
IPv4 ICMP ct-tuple:
"ct_nw_src=10.1.1.1,ct_nw_dst=10.1.1.2,ct_nw_proto=1,icmp_type=8,icmp_code=0,icmp_id=10"
An example of an IPv6 TCP ct-tuple:
"ct_ipv6_src=fc00::1,ct_ipv6_dst=fc00::2,ct_nw_proto=6,ct_tp_src=1,ct_tp_dst=2"
[-m | --more] ct-stats-show [dp] [zone=zone]
Displays the number of connections grouped by protocol
used by dp. If zone=zone is specified, numbers refer to
the connections in zone. With --more, groups by
connection state for each protocol.
ct-bkts [dp] [gt=threshold]
For each conntrack bucket, displays the number of
connections used by dp. If gt=threshold is specified,
bucket numbers are displayed when the number of
connections in a bucket is greater than threshold.
ct-set-maxconns [dp] maxconns
Sets the maximum limit of connection tracker entries to
maxconns on dp. This can be used to reduce the processing
load on the system due to connection tracking or simply
limiting connection tracking. If the number of
connections is already over the new maximum limit request
then the new maximum limit will be enforced when the
number of connections decreases to that limit, which
normally happens due to connection expiry. Only supported
for userspace datapath.
ct-get-maxconns [dp]
Prints the maximum limit of connection tracker entries on
dp. Only supported for userspace datapath.
ct-get-nconns [dp]
Prints the current number of connection tracker entries on
dp. Only supported for userspace datapath.
ct-enable-tcp-seq-chk [dp]
ct-disable-tcp-seq-chk [dp]
Enables or disables TCP sequence checking. When set to
disabled, all sequence number verification is disabled,
including for TCP resets. This is similar, but not the
same as 'be_liberal' mode, as in Netfilter. Disabling
sequence number verification is not an optimization in
itself, but is needed for some hardware offload support
which might offer some performance advantage. Sequence
number checking is enabled by default to enforce better
security and should only be disabled if required for
hardware offload support. This command is only supported
for the userspace datapath.
ct-get-tcp-seq-chk [dp]
Prints whether TCP sequence checking is enabled or
disabled on dp. Only supported for the userspace
datapath.
ct-set-limits [dp] [default=default_limit]
[zone=zone,limit=limit]...
Sets the maximum allowed number of connections in a
connection tracking zone. A specific zone may be set to
limit, and multiple zones may be specified with a comma-
separated list. If a per-zone limit for a particular zone
is not specified in the datapath, it defaults to the
default per-zone limit. A default zone may be specified
with the default=default_limit argument. Initially, the
default per-zone limit is unlimited. An unlimited number
of entries may be set with 0 limit.
ct-del-limits [dp] zone=zone[,zone]...
Deletes the connection tracking limit for zone. Multiple
zones may be specified with a comma-separated list.
ct-get-limits [dp] [zone=zone[,zone]...]
Retrieves the maximum allowed number of connections and
current counts per-zone. If zone is given, only the
specified zone(s) are printed. If no zones are specified,
all the zone limits and counts are provided. The command
always displays the default zone limit.
