ip


SYNOPSIS
       ip [ OPTIONS ] OBJECT { COMMAND | help }


       OBJECT := { link | addr | addrlabel | route | rule | neigh | tunnel |
               maddr | mroute }


       OPTIONS := { -V[ersion] | -s[tatistics] | -r[esolve] | -f[amily] { inet
               | inet6 | ipx | dnet | link } | -o[neline] }

       ip link add link DEVICE [ name ] NAME
               [ txqueuelen PACKETS ]
               [ address LLADDR ] [ broadcast LLADDR ]
               [ mtu MTU ]
               type TYPE [ ARGS ]

       TYPE := [ vlan | veth | vcan | dummy | ifb | macvlan | can | bridge]"

       ip link delete DEVICE type TYPE [ ARGS ]

       ip link set { DEVICE | group GROUP } { up | down | arp { on | off } |
               promisc { on | off } |
               allmulticast { on | off } |
               dynamic { on | off } |
               multicast { on | off } |
               txqueuelen PACKETS |
               name NEWNAME |
               address LLADDR | broadcast LLADDR |
               mtu MTU |
               netns PID |
               netns NETNSNAME |
               alias NAME |
               vf NUM [ mac LLADDR ] [ vlan VLANID [ qos VLAN-QOS ] ] [ rate
               TXRATE ] |
               master DEVICE
               nomaster  }


       ip link show [ DEVICE | group GROUP ]

       ip addr { add | del } IFADDR dev STRING

       ip addr { show | flush } [ dev STRING ] [ scope SCOPE-ID ] [ to PREFIX
               ] [ FLAG-LIST ] [ label PATTERN ]

       IFADDR := PREFIX | ADDR peer PREFIX [ broadcast ADDR ] [ anycast ADDR ]
               [ label STRING ] [ scope SCOPE-ID ]

       SCOPE-ID := [ host | link | global | NUMBER ]

       FLAG-LIST := [ FLAG-LIST ] FLAG


       ip route { list | flush } SELECTOR

       ip route save SELECTOR

       ip route restore

       ip route get ADDRESS [ from ADDRESS iif STRING  ] [ oif STRING ] [ tos
               TOS ]

       ip route { add | del | change | append | replace } ROUTE

       SELECTOR := [ root PREFIX ] [ match PREFIX ] [ exact PREFIX ] [ table
               TABLE_ID ] [ proto RTPROTO ] [ type TYPE ] [ scope SCOPE ]

       ROUTE := NODE_SPEC [ INFO_SPEC ]

       NODE_SPEC := [ TYPE ] PREFIX [ tos TOS ] [ table TABLE_ID ] [ proto
               RTPROTO ] [ scope SCOPE ] [ metric METRIC ]

       INFO_SPEC := NH OPTIONS FLAGS [ nexthop NH ] ...

       NH := [ via ADDRESS ] [ dev STRING ] [ weight NUMBER ] NHFLAGS

       OPTIONS := FLAGS [ mtu NUMBER ] [ advmss NUMBER ] [ rtt TIME ] [ rttvar
               TIME ] [ window NUMBER ] [ cwnd NUMBER ] [ ssthresh REALM ] [
               realms REALM ] [ rto_min TIME ] [ initcwnd NUMBER ] [ initrwnd
               NUMBER ]

       TYPE := [ unicast | local | broadcast | multicast | throw | unreachable
               | prohibit | blackhole | nat ]

       TABLE_ID := [ local| main | default | all | NUMBER ]

       SCOPE := [ host | link | global | NUMBER ]

       NHFLAGS := [ onlink | pervasive ]

       RTPROTO := [ kernel | boot | static | NUMBER ]

       ip rule  [ list | add | del | flush ] SELECTOR ACTION

       SELECTOR := [ from PREFIX ] [ to PREFIX ] [ tos TOS ] [ fwmark
               FWMARK[/MASK] ] [ iif STRING ] [ oif STRING ] [ pref NUMBER ]

       ACTION := [ table TABLE_ID ] [ nat ADDRESS ] [ prohibit | reject |
               unreachable ] [ realms [SRCREALM/]DSTREALM ]

       TABLE_ID := [ local | main | default | NUMBER ]

       ip neigh { add | del | change | replace } { ADDR [ lladdr LLADDR ] [
               nud { permanent | noarp | stale | reachable } ] | proxy ADDR }
               [ dev DEV ]

       ip tunnel { add | change | del | show | prl } [ NAME ]
               [ mode MODE ] [ remote ADDR ] [ local ADDR ]
               [ [i|o]seq ] [ [i|o]key KEY ] [ [i|o]csum ] ]
               [ encaplimit ELIM ] [ ttl TTL ]
               [ tos TOS ] [ flowlabel FLOWLABEL ]
               [ prl-default ADDR ] [ prl-nodefault ADDR ] [ prl-delete ADDR ]
               [ [no]pmtudisc ] [ dev PHYS_DEV ] [ dscp inherit ]

       MODE :=  { ipip | gre | sit | isatap | ip6ip6 | ipip6 | any }

       ADDR := { IP_ADDRESS | any }

       TOS := { NUMBER | inherit }

       ELIM := { none | 0..255 }

       TTL := { 1..255 | inherit }

       KEY := { DOTTED_QUAD | NUMBER }

       TIME := NUMBER[s|ms]

       ip maddr [ add | del ] MULTIADDR dev STRING

       ip maddr show [ dev STRING ]

       ip mroute show [ PREFIX ] [ from PREFIX ] [ iif DEVICE ]

       ip monitor [ all | LISTofOBJECTS ]


       ip xfrm XFRM-OBJECT { COMMAND | help }


       XFRM-OBJECT := state | policy | monitor


       ip xfrm state { add | update } ID [ ALGO-LIST ] [ mode MODE ] [ mark
               MARK [ mask MASK ] ] [ reqid REQID ] [ seq SEQ ] [ replay-win-
               dow SIZE ] [ replay-seq SEQ ] [ replay-oseq SEQ ] [ flag FLAG-
               LIST ] [ sel SELECTOR ] [ LIMIT-LIST ] [ encap ENCAP ] [ coa
               ADDR[/PLEN] ] [ ctx CTX ]

       ip xfrm state allocspi ID [ mode MODE ] [ mark MARK [ mask MASK ] ] [
               reqid REQID ] [ seq SEQ ] [ min SPI max SPI ]

       ip xfrm state { delete | get } ID [ mark MARK [ mask MASK ] ]

       ip xfrm state { deleteall | list } [ ID ] [ mode MODE ] [ reqid REQID ]
               [ flag FLAG-LIST ]

       ip xfrm state flush [ proto XFRM-PROTO ]

       ip xfrm state count

       FLAG-LIST := [ FLAG-LIST ] FLAG

       FLAG := noecn | decap-dscp | nopmtudisc | wildrecv | icmp | af-unspec |
               align4

       SELECTOR := [ src ADDR[/PLEN] ] [ dst ADDR[/PLEN] ] [ dev DEV ]
               [ UPSPEC ]

       UPSPEC := proto { PROTO |
               { tcp | udp | sctp | dccp } [ sport PORT ] [ dport PORT ] |
               { icmp | ipv6-icmp | mobility-header } [ type NUMBER ] [ code
               NUMBER ] |
               gre [ key { DOTTED-QUAD | NUMBER } ] }

       LIMIT-LIST := [ LIMIT-LIST ] limit LIMIT

       LIMIT := { time-soft | time-hard | time-use-soft | time-use-hard } SEC-
               ONDS |
               { byte-soft | byte-hard } SIZE |
               { packet-soft | packet-hard } COUNT

       ENCAP := { espinudp | espinudp-nonike } SPORT DPORT OADDR

       ip xfrm policy { add | update } SELECTOR dir DIR [ ctx CTX ] [ mark
               MARK [ mask MASK ] ] [ index INDEX ] [ ptype PTYPE ] [ action
               ACTION ] [ priority PRIORITY ] [ flag FLAG-LIST ] [ LIMIT-LIST
               ] [ TMPL-LIST ]

       ip xfrm policy { delete | get } { SELECTOR | index INDEX } dir DIR [
               ctx CTX ] [ mark MARK [ mask MASK ] ] [ ptype PTYPE ]

       ip xfrm policy { deleteall | list } [ SELECTOR ] [ dir DIR ] [ index
               INDEX ] [ ptype PTYPE ] [ action ACTION ] [ priority PRIORITY ]

       ip xfrm policy flush [ ptype PTYPE ]

       ip xfrm policy count

       SELECTOR := [ src ADDR[/PLEN] ] [ dst ADDR[/PLEN] ] [ dev DEV ] [
               UPSPEC ]

       UPSPEC := proto { PROTO |
               { tcp | udp | sctp | dccp } [ sport PORT ] [ dport PORT ] |
               { icmp | ipv6-icmp | mobility-header } [ type NUMBER ] [ code
               NUMBER ] |
               gre [ key { DOTTED-QUAD | NUMBER } ] }

       DIR := in | out | fwd

       PTYPE := main | sub

       ACTION := allow | block


       TMPL := ID [ mode MODE ] [ reqid REQID ] [ level LEVEL ]

       ID := [ src ADDR ] [ dst ADDR ] [ proto XFRM-PROTO ] [ spi SPI ]

       XFRM-PROTO := esp | ah | comp | route2 | hao

       MODE := transport | tunnel | ro | in_trigger | beet

       LEVEL := required | use

       ip xfrm monitor [ all | LISTofXFRM-OBJECTS ]



OPTIONS
       -V, -Version
              print the version of the ip utility and exit.


       -s, -stats, -statistics
              output  more  information.  If the option appears twice or more,
              the amount of information increases.  As a rule, the information
              is statistics or some time values.


       -l, -loops
              Specify  maximum  number of loops the 'ip addr flush' logic will
              attempt before giving up.  The default is 10.   Zero  (0)  means
              loop until all addresses are removed.


       -f, -family
              followed  by  protocol  family  identifier:  inet, inet6 or link
              ,enforce the protocol family to  use.   If  the  option  is  not
              present,  the  protocol  family is guessed from other arguments.
              If the rest of the command line does not give enough information
              to  guess  the family, ip falls back to the default one, usually
              inet or any.  link is a special family identifier  meaning  that
              no networking protocol is involved.


       -4     shortcut for -family inet.


       -6     shortcut for -family inet6.


       -0     shortcut for -family link.


       -o, -oneline
              output  each  record on a single line, replacing line feeds with
              the '\' character. This is convenient when  you  want  to  count


       address
              - protocol (IP or IPv6) address on a device.


       addrlabel
              - label configuration for protocol address selection.


       neighbour
              - ARP or NDISC cache entry.


       route  - routing table entry.


       rule   - rule in routing policy database.


       maddress
              - multicast address.


       mroute - multicast routing cache entry.


       tunnel - tunnel over IP.


       The names of all objects may be written in full  or  abbreviated  form,
       f.e.  address is abbreviated as addr or just a.


   COMMAND
       Specifies  the  action  to  perform on the object.  The set of possible
       actions depends on the object type.  As a rule, it is possible to  add,
       delete  and  show (or list ) objects, but some objects do not allow all
       of these operations or have some additional commands.  The help command
       is  available  for all objects.  It prints out a list of available com-
       mands and argument syntax conventions.

       If no command is given, some default command is assumed.  Usually it is
       list or, if the objects of this class cannot be listed, help.


ip link - network device configuration
       link  is  a  network  device and the corresponding commands display and
       change the state of devices.


   ip link add - add virtual link
       link DEVICE
              specifies the physical device to act operate on.

                      dummy - Dummy network interface

                      ifb - Intermediate Functional Block device

                      macvlan - virtual interface base on link  layer  address
                      (MAC)

                      can - Controller Area Network interface

                      bridge - Ethernet Bridge device


   ip link delete - delete virtual link
       DEVICE specifies the virtual  device to act operate on.  TYPE specifies
       the type of the device.



       dev DEVICE
              specifies the physical device to act operate on.


   ip link set - change device attributes
       dev DEVICE
              DEVICE specifies network device to operate on. When  configuring
              SR-IOV Virtual Fuction (VF) devices, this keyword should specify
              the associated Physical Function (PF) device.


       group GROUP
              GROUP has a dual role: If both group and dev are  present,  then
              move  the  device  to  the  specified group.  If only a group is
              specified, then the command operates  on  all  devices  in  that
              group.


       up and down
              change the state of the device to UP or DOWN.


       arp on or arp off
              change the NOARP flag on the device.


       multicast on or multicast off
              change the MULTICAST flag on the device.


       dynamic on or dynamic off
              change the DYNAMIC flag on the device.


       name NAME
              change the MTU of the device.


       address LLADDRESS
              change the station address of the interface.


       broadcast LLADDRESS

       brd LLADDRESS

       peer LLADDRESS
              change the link layer broadcast address or the peer address when
              the interface is POINTOPOINT.


       netns PID
              move the device to the network  namespace  associated  with  the
              process PID.


       netns NETNSNAME
              move  the  device  to the network namespace associated with name
              NETNSNAME.


       alias NAME
              give the device a symbolic name for easy reference.


       group GROUP
              specify the group the device belongs to.  The  available  groups
              are listed in file /etc/iproute2/group.


       vf NUM specify  a Virtual Function device to be configured. The associ-
              ated PF device must be specified using the dev parameter.

                      mac LLADDRESS - change the station address for the spec-
                      ified VF. The vf parameter must be specified.


                      vlan VLANID - change the assigned VLAN for the specified
                      VF. When specified, all traffic sent from the VF will be
                      tagged with the specified VLAN ID. Incoming traffic will
                      be filtered for the specified VLAN ID, and will have all
                      VLAN  tags  stripped before being passed to the VF. Set-
                      ting this parameter to 0 disables VLAN tagging and  fil-
                      tering. The vf parameter must be specified.


                      qos  VLAN-QOS  - assign VLAN QOS (priority) bits for the
                      VLAN tag. When specified, all VLAN tags  transmitted  by
                      the  VF  will include the specified priority bits in the

       master DEVICE
              set master device of the device (enslave device).


       nomaster
              unset master device of the device (release device).


       Warning: If multiple parameter changes are requested, ip aborts immedi-
       ately after any of the changes have failed.  This is the only case when
       ip can move the system to an unpredictable state.  The solution  is  to
       avoid changing several parameters with one ip link set call.


   ip link show - display device attributes
       dev NAME (default)
              NAME  specifies the network device to show.  If this argument is
              omitted all devices in the default group are listed.


       group GROUP
              GROUP specifies what group of devices to show.


       up     only display running interfaces.


ip address - protocol address management.
       The address is a protocol (IP or IPv6) address attached  to  a  network
       device.   Each  device must have at least one address to use the corre-
       sponding protocol.  It is possible to have several different  addresses
       attached to one device.  These addresses are not discriminated, so that
       the term alias is not quite appropriate for them and we do not  use  it
       in this document.

       The  ip  addr command displays addresses and their properties, adds new
       addresses and deletes old ones.


   ip address add - add new protocol address.
       dev NAME
              the name of the device to add the address to.


       local ADDRESS (default)
              the address of the interface. The format of the address  depends
              on  the  protocol.  It is a dotted quad for IP and a sequence of
              hexadecimal halfwords separated by colons for IPv6.  The ADDRESS
              may  be  followed  by a slash and a decimal number which encodes
              the network prefix length.


       peer ADDRESS
              the address of the remote endpoint for  pointopoint  interfaces.
              derived by setting/resetting the host bits of the interface pre-
              fix.


       label NAME
              Each address may be tagged with a label  string.   In  order  to
              preserve  compatibility  with Linux-2.0 net aliases, this string
              must coincide with the name of the device or  must  be  prefixed
              with the device name followed by colon.


       scope SCOPE_VALUE
              the  scope  of the area where this address is valid.  The avail-
              able scopes are listed in file /etc/iproute2/rt_scopes.   Prede-
              fined scope values are:

                      global - the address is globally valid.

                      site - (IPv6 only) the address is site local, i.e. it is
                      valid inside this site.

                      link - the address is link local, i.e. it is valid  only
                      on this device.

                      host - the address is valid only inside this host.


   ip address delete - delete protocol address
       Arguments: coincide with the arguments of ip addr add.  The device name
       is a required argument.  The rest are optional.  If  no  arguments  are
       given, the first address is deleted.


   ip address show - look at protocol addresses
       dev NAME (default)
              name of device.


       scope SCOPE_VAL
              only list addresses with this scope.


       to PREFIX
              only list addresses matching this prefix.


       label PATTERN
              only  list  addresses with labels matching the PATTERN.  PATTERN
              is a usual shell style pattern.


       dynamic and permanent
              (IPv6 only) only  list  addresses  installed  due  to  stateless
              address  configuration  or  only  list  permanent  (not dynamic)

       dadfailed
              (IPv6  only)  only  list  addresses  which have failed duplicate
              address detection.


       temporary
              (IPv6 only) only list temporary addresses.


       primary and secondary
              only list primary (or secondary) addresses.


   ip address flush - flush protocol addresses
       This command flushes the protocol addresses selected by some criteria.


       This command has the same arguments as show.  The difference is that it
       does not run when no arguments are given.


       Warning:  This  command  (and  other flush commands described below) is
       pretty dangerous.  If you make a mistake, it will not forgive  it,  but
       will cruelly purge all the addresses.


       With the -statistics option, the command becomes verbose. It prints out
       the number of deleted addresses and the number of rounds made to  flush
       the  address  list.   If this option is given twice, ip addr flush also
       dumps all the deleted addresses in the format described in the previous
       subsection.


ip addrlabel - protocol address label management.
       IPv6 address label is used for address selection described in RFC 3484.
       Precedence is managed by userspace, and only label is stored in kernel.


   ip addrlabel add - add an address label
       the command adds an address label entry to the kernel.

       prefix PREFIX

       dev DEV
              the outgoing interface.

       label NUMBER
              the label for the prefix.  0xffffffff is reserved.

   ip addrlabel del - delete an address label
       the command deletes an address label entry in the  kernel.   Arguments:
       coincide  with  the  arguments  of  ip  addrlabel  add but label is not
       required.



       The corresponding commands display neighbour bindings and their proper-
       ties, add new neighbour entries and delete old ones.


   ip neighbour add - add a new neighbour entry
   ip neighbour change - change an existing entry
   ip neighbour replace - add a new entry or change an existing one
       These commands create new neighbour records or update existing ones.


       to ADDRESS (default)
              the  protocol  address of the neighbour. It is either an IPv4 or
              IPv6 address.


       dev NAME
              the interface to which this neighbour is attached.


       lladdr LLADDRESS
              the link layer address of the neighbour.  LLADDRESS can also  be
              null.


       nud NUD_STATE
              the  state  of  the neighbour entry.  nud is an abbreviation for
              'Neighbour Unreachability Detection'.  The state can take one of
              the following values:

                      permanent - the neighbour entry is valid forever and can
                      be only be removed administratively.


                      noarp - the neighbour entry is  valid.  No  attempts  to
                      validate  this  entry will be made but it can be removed
                      when its lifetime expires.


                      reachable - the  neighbour  entry  is  valid  until  the
                      reachability timeout expires.


                      stale  -  the  neighbour  entry is valid but suspicious.
                      This option to ip neigh does not  change  the  neighbour
                      state  if it was valid and the address is not changed by
                      this command.


   ip neighbour delete - delete a neighbour entry
       This command invalidates a neighbour entry.




       to ADDRESS (default)
              the prefix selecting the neighbours to list.


       dev NAME
              only list the neighbours attached to this device.


       unused only list neighbours which are not currently in use.


       nud NUD_STATE
              only list neighbour entries in this state.  NUD_STATE takes val-
              ues  listed  below  or  the  special  value  all which means all
              states.  This option may occur more than once.  If  this  option
              is absent, ip lists all entries except for none and noarp.


   ip neighbour flush - flush neighbour entries
       This  command  flushes  neighbour tables, selecting entries to flush by
       some criteria.


       This command has the same arguments as show.  The differences are  that
       it  does  not  run  when  no  arguments are given, and that the default
       neighbour states to be flushed do not include permanent and noarp.


       With the -statistics option, the command becomes  verbose.   It  prints
       out  the  number of deleted neighbours and the number of rounds made to
       flush the neighbour table.  If the option  is  given  twice,  ip  neigh
       flush also dumps all the deleted neighbours.


ip ntable - neighbour table configuration
       Display and change the parameters for the neighbour tables.


   ip ntable show - list the ip neighbour tables
       This commands displays neighbour table parameters and statistics.


       dev DEV
              only list the table attached to this device.


       name NAME
              only lists the table with the given name.


   ip ntable change - modify table parameter
       This command allows modifying table parameters such as timers and queue
       about paths to other networked nodes.

       Route types:

               unicast  - the route entry describes real paths to the destina-
               tions covered by the route prefix.


               unreachable - these destinations are unreachable.  Packets  are
               discarded  and  the ICMP message host unreachable is generated.
               The local senders get an EHOSTUNREACH error.


               blackhole - these destinations are  unreachable.   Packets  are
               discarded silently.  The local senders get an EINVAL error.


               prohibit  -  these  destinations  are unreachable.  Packets are
               discarded and the ICMP message  communication  administratively
               prohibited  is  generated.   The  local  senders  get an EACCES
               error.


               local - the destinations are assigned to this host.  The  pack-
               ets are looped back and delivered locally.


               broadcast  -  the  destinations  are  broadcast addresses.  The
               packets are sent as link broadcasts.


               throw - a special  control  route  used  together  with  policy
               rules.  If  such  a  route is selected, lookup in this table is
               terminated pretending that no route was found.  Without  policy
               routing  it  is  equivalent  to the absence of the route in the
               routing table.  The packets are dropped and  the  ICMP  message
               net unreachable is generated.  The local senders get an ENETUN-
               REACH error.


               nat - a special NAT route.  Destinations covered by the  prefix
               are  considered  to  be  dummy  (or  external)  addresses which
               require translation to real (or internal) ones before  forward-
               ing.   The  addresses  to  translate  to  are selected with the
               attribute Warning: Route NAT is no longer  supported  in  Linux
               2.6.


               via.

               anycast   -   not  implemented  the  destinations  are  anycast
               addresses assigned to this host.  They are mainly equivalent to
               local with one difference: such addresses are invalid when used
               as the source address of any packet.


       Actually, one other table always exists, which is  invisible  but  even
       more  important.   It is the local table (ID 255).  This table consists
       of routes for local and broadcast addresses.  The kernel maintains this
       table automatically and the administrator usually need not modify it or
       even look at it.

       The multiple routing tables enter the game when policy routing is used.


   ip route add - add new route
   ip route change - change route
   ip route replace - change or add new one
       to TYPE PREFIX (default)
              the destination prefix of the route.  If  TYPE  is  omitted,  ip
              assumes  type  unicast.   Other values of TYPE are listed above.
              PREFIX is an IP or IPv6 address optionally followed by  a  slash
              and  the prefix length.  If the length of the prefix is missing,
              ip assumes a full-length host route.  There is  also  a  special
              PREFIX default - which is equivalent to IP 0/0 or to IPv6 ::/0.


       tos TOS

       dsfield TOS
              the  Type Of Service (TOS) key.  This key has no associated mask
              and the longest match is understood as: First, compare  the  TOS
              of the route and of the packet.  If they are not equal, then the
              packet may still match a route with a zero TOS.  TOS  is  either
              an   8   bit   hexadecimal   number   or   an   identifier  from
              /etc/iproute2/rt_dsfield.


       metric NUMBER

       preference NUMBER
              the preference value of the route.  NUMBER is an arbitrary 32bit
              number.


       table TABLEID
              the  table  to  add this route to.  TABLEID may be a number or a
              string from the file /etc/iproute2/rt_tables.  If this parameter
              is  omitted,  ip  assumes  the main table, with the exception of
              local , broadcast and nat routes, which are put into  the  local
              table by default.


       dev NAME
              the output device name.


       via ADDRESS

       realm REALMID
              the  realm  to  which  this route is assigned.  REALMID may be a
              number or a string from the file /etc/iproute2/rt_realms.


       mtu MTU

       mtu lock MTU
              the MTU along the path to the destination.  If the modifier lock
              is  not  used,  the MTU may be updated by the kernel due to Path
              MTU Discovery.  If the modifier lock is used, no path  MTU  dis-
              covery  will  be  tried, all packets will be sent without the DF
              bit in IPv4 case or fragmented to MTU for IPv6.


       window NUMBER
              the maximal window for TCP to advertise to  these  destinations,
              measured  in  bytes.  It limits maximal data bursts that our TCP
              peers are allowed to send to us.


       rtt TIME
              the initial RTT ('Round Trip Time') estimate. If  no  suffix  is
              specified  the units are raw values passed directly to the rout-
              ing code to maintain compatibility with previous releases.  Oth-
              erwise  if a suffix of s, sec or secs is used to specify seconds
              and ms, msec or msecs to specify milliseconds.



       rttvar TIME (2.3.15+ only)
              the initial RTT variance estimate. Values are specified as  with
              rtt above.


       rto_min TIME (2.6.23+ only)
              the minimum TCP Retransmission TimeOut to use when communicating
              with this destination.  Values are specified as with rtt above.


       ssthresh NUMBER (2.3.15+ only)
              an estimate for the initial slow start threshold.


       cwnd NUMBER (2.3.15+ only)
              the clamp for congestion window.  It is ignored if the lock flag
              is not used.


       initcwnd NUMBER (2.5.70+ only)
              the  initial congestion window size for connections to this des-
              tination.  Actual window size is this value  multiplied  by  the
              MSS  (``Maximal Segment Size'') for same connection. The default
              tions when establishing TCP connections.  If it  is  not  given,
              Linux  uses a default value calculated from the first hop device
              MTU.  (If the path to  these  destination  is  asymmetric,  this
              guess may be wrong.)


       reordering NUMBER (2.3.15+ only)
              Maximal  reordering  on  the path to this destination.  If it is
              not given, Linux uses the value selected  with  sysctl  variable
              net/ipv4/tcp_reordering.


       nexthop NEXTHOP
              the  nexthop  of  a multipath route.  NEXTHOP is a complex value
              with its own syntax similar to the top level argument lists:

                      via ADDRESS - is the nexthop router.


                      dev NAME - is the output device.


                      weight NUMBER - is a weight for this element of a multi-
                      path route reflecting its relative bandwidth or quality.


       scope SCOPE_VAL
              the  scope  of  the  destinations  covered  by the route prefix.
              SCOPE_VAL  may  be  a  number  or  a  string   from   the   file
              /etc/iproute2/rt_scopes.   If  this  parameter  is  omitted,  ip
              assumes scope global for all  gatewayed  unicast  routes,  scope
              link  for direct unicast and broadcast routes and scope host for
              local routes.


       protocol RTPROTO
              the routing protocol identifier of this route.  RTPROTO may be a
              number  or  a  string from the file /etc/iproute2/rt_protos.  If
              the routing protocol ID is not given, ip assumes  protocol  boot
              (i.e.  it  assumes  the  route  was added by someone who doesn't
              understand what they are doing).  Several protocol values have a
              fixed interpretation.  Namely:

                      redirect  - the route was installed due to an ICMP redi-
                      rect.


                      kernel - the route was installed by  the  kernel  during
                      autoconfiguration.


                      boot  -  the  route  was  installed  during  the  bootup
                      sequence.  If a routing daemon starts, it will purge all
                      of them.

              free to assign (or not to assign) protocol tags.


       onlink pretend that the nexthop is directly attached to this link, even
              if it does not match any interface prefix.


   ip route delete - delete route
       ip route del has the same arguments as ip route add, but  their  seman-
       tics are a bit different.

       Key  values (to, tos, preference and table) select the route to delete.
       If optional attributes are present, ip verifies that they coincide with
       the  attributes of the route to delete.  If no route with the given key
       and attributes was found, ip route del fails.


   ip route show - list routes
       the command displays the contents of the routing tables or the route(s)
       selected by some criteria.


       to SELECTOR (default)
              only select routes from the given range of destinations.  SELEC-
              TOR consists of an optional modifier (root, match or exact)  and
              a  prefix.  root PREFIX selects routes with prefixes not shorter
              than PREFIX.  F.e.  root 0/0 selects the entire  routing  table.
              match  PREFIX  selects routes with prefixes not longer than PRE-
              FIX.  F.e.  match 10.0/16 selects 10.0/16, 10/8 and 0/0, but  it
              does  not  select  10.1/16  and 10.0.0/24.  And exact PREFIX (or
              just PREFIX) selects routes with this exact prefix.  If  neither
              of  these options are present, ip assumes root 0/0 i.e. it lists
              the entire table.


       tos TOS
              dsfield TOS only select routes with the given TOS.


       table TABLEID
              show the routes from this table(s).  The default setting  is  to
              show tablemain.  TABLEID may either be the ID of a real table or
              one of the special values:

                      all - list all of the tables.

                      cache - dump the routing cache.


       cloned

       cached list cloned routes i.e. routes  which  were  dynamically  forked
              from  other  routes  because some route attribute (f.e. MTU) was
              updated.  Actually, it is equivalent to table cache.

       scope SCOPE_VAL
              only list routes with this scope.


       type TYPE
              only list routes of this type.


       dev NAME
              only list routes going via this device.


       via PREFIX
              only list routes going via the nexthop routers selected by  PRE-
              FIX.


       src PREFIX
              only  list  routes  with  preferred source addresses selected by
              PREFIX.


       realm REALMID

       realms FROMREALM/TOREALM
              only list routes with these realms.


   ip route flush - flush routing tables
       this command flushes routes selected by some criteria.


       The arguments have the same syntax and semantics as the arguments of ip
       route  show,  but  routing  tables are not listed but purged.  The only
       difference is the default action: show dumps all the  IP  main  routing
       table but flush prints the helper page.


       With the -statistics option, the command becomes verbose. It prints out
       the number of deleted routes and the number of rounds made to flush the
       routing  table. If the option is given twice, ip route flush also dumps
       all the deleted routes in the format described in the previous  subsec-
       tion.


   ip route get - get a single route
       this  command  gets a single route to a destination and prints its con-
       tents exactly as the kernel sees it.


       to ADDRESS (default)
              the destination address.




       oif NAME
              force the output device on which this packet will be routed.


       connected
              if no source address (option from) was given, relookup the route
              with  the  source set to the preferred address received from the
              first lookup.  If policy routing is used, it may be a  different
              route.


       Note  that  this  operation  is  not equivalent to ip route show.  show
       shows existing routes.  get resolves them and  creates  new  clones  if
       necessary.   Essentially,  get  is equivalent to sending a packet along
       this path.  If the iif argument is not  given,  the  kernel  creates  a
       route  to  output  packets  towards the requested destination.  This is
       equivalent to pinging the destination with a  subsequent  ip  route  ls
       cache,  however,  no packets are actually sent.  With the iif argument,
       the kernel pretends that a  packet  arrived  from  this  interface  and
       searches for a path to forward the packet.


   ip route save - save routing table information to stdout
       this  command  behaves like ip route show except that the output is raw
       data suitable for passing to ip route restore.


   ip route restore - restore routing table information from stdin
       this command expects to read a data stream as returned  from  ip  route
       save.  It will attempt to restore the routing table information exactly
       as it was at the time of the save, so any translation of information in
       the  stream  (such as device indexes) must be done first.  Any existing
       routes are left unchanged.  Any routes specified  in  the  data  stream
       that already exist in the table will be ignored.


ip rule - routing policy database management
       Rules  in the routing policy database control the route selection algo-
       rithm.


       Classic routing algorithms used in the Internet make routing  decisions
       based  only  on  the destination address of packets (and in theory, but
       not in practice, on the TOS field).


       In some circumstances we want to route  packets  differently  depending
       not  only  on  destination  addresses, but also on other packet fields:
       source address, IP protocol, transport protocol ports  or  even  packet
       payload.  This task is called 'policy routing'.


       indication and the RPDB lookup is terminated. Otherwise, the RPDB  pro-
       gram continues on the next rule.


       Semantically,  natural  action  is to select the nexthop and the output
       device.


       At startup time the kernel configures the default  RPDB  consisting  of
       three rules:


       1.     Priority:  0,  Selector:  match anything, Action: lookup routing
              table local (ID 255).  The local table is a special routing  ta-
              ble containing high priority control routes for local and broad-
              cast addresses.

              Rule 0 is special. It cannot be deleted or overridden.


       2.     Priority: 32766, Selector: match anything, Action: lookup  rout-
              ing  table  main (ID 254).  The main table is the normal routing
              table containing all non-policy routes. This rule may be deleted
              and/or overridden with other ones by the administrator.


       3.     Priority:  32767, Selector: match anything, Action: lookup rout-
              ing table default (ID 253).  The default table is empty.  It  is
              reserved  for  some post-processing if no previous default rules
              selected the packet.  This rule may also be deleted.


       Each RPDB entry has  additional  attributes.   F.e.  each  rule  has  a
       pointer  to  some  routing  table.   NAT and masquerading rules have an
       attribute to select new IP address  to  translate/masquerade.   Besides
       that,  rules  have  some optional attributes, which routes have, namely
       realms.  These values do not override those contained  in  the  routing
       tables.  They are only used if the route did not select any attributes.


       The RPDB may contain rules of the following types:

               unicast  - the rule prescribes to return the route found in the
               routing table referenced by the rule.

               blackhole - the rule prescribes to silently drop the packet.

               unreachable - the rule prescribes to  generate  a  'Network  is
               unreachable' error.

               prohibit  -  the  rule prescribes to generate 'Communication is
               administratively prohibited' error.

               nat - the rule prescribes to translate the  source  address  of


       to PREFIX
              select the destination prefix to match.


       iif NAME
              select the incoming device to match.  If the interface is  loop-
              back,  the rule only matches packets originating from this host.
              This means that you may create separate routing tables for  for-
              warded and local packets and, hence, completely segregate them.


       oif NAME
              select  the outgoing device to match.  The outgoing interface is
              only available for packets originating from local  sockets  that
              are bound to a device.


       tos TOS

       dsfield TOS
              select the TOS value to match.


       fwmark MARK
              select the fwmark value to match.


       priority PREFERENCE
              the  priority of this rule.  Each rule should have an explicitly
              set unique priority value.  The options preference and order are
              synonyms with priority.


       table TABLEID
              the  routing  table  identifier  to  lookup if the rule selector
              matches.  It is also possible to use lookup instead of table.


       realms FROM/TO
              Realms to select if the  rule  matched  and  the  routing  table
              lookup  succeeded.   Realm  TO is only used if the route did not
              select any realm.


       nat ADDRESS
              The base of the  IP  address  block  to  translate  (for  source
              addresses).  The ADDRESS may be either the start of the block of
              NAT addresses (selected by NAT routes) or a local  host  address
              (or  even zero).  In the last case the router does not translate
              the packets, but masquerades them to this address.  Using map-to
              instead of nat means the same thing.

       with show.


ip maddress - multicast addresses management
       maddress objects are multicast addresses.


   ip maddress show - list multicast addresses
       dev NAME (default)
              the device name.


   ip maddress add - add a multicast address
   ip maddress delete - delete a multicast address
       these  commands  attach/detach a static link layer multicast address to
       listen on the interface.  Note that it is impossible to  join  protocol
       multicast  groups  statically.   This  command  only manages link layer
       addresses.


       address LLADDRESS (default)
              the link layer multicast address.


       dev NAME
              the device to join/leave this multicast address.


ip mroute - multicast routing cache management
       mroute objects are multicast routing cache entries created  by  a  user
       level mrouting daemon (f.e.  pimd or mrouted ).

       Due  to the limitations of the current interface to the multicast rout-
       ing engine, it is impossible to change mroute objects administratively,
       so  we  may  only display them.  This limitation will be removed in the
       future.


   ip mroute show - list mroute cache entries
       to PREFIX (default)
              the prefix selecting  the  destination  multicast  addresses  to
              list.


       iif NAME
              the interface on which multicast packets are received.


       from PREFIX
              the  prefix  selecting  the IP source addresses of the multicast
              route.


ip tunnel - tunnel configuration

       mode MODE
              set the tunnel mode. Available modes depend on the encapsulating
              address family.
              Modes for IPv4 encapsulation available: ipip,  sit,  isatap  and
              gre.
              Modes for IPv6 encapsulation available: ip6ip6, ipip6 and any.


       remote ADDRESS
              set the remote endpoint of the tunnel.


       local ADDRESS
              set the fixed local address for tunneled packets.  It must be an
              address on another interface of this host.


       ttl N  set a fixed TTL N on tunneled packets.  N is  a  number  in  the
              range  1--255. 0 is a special value meaning that packets inherit
              the TTL value.  The default value for IPv4 tunnels is:  inherit.
              The default value for IPv6 tunnels is: 64.



       tos T

       dsfield T

       tclass T
              set  a  fixed TOS (or traffic class in IPv6) T on tunneled pack-
              ets.  The default value is: inherit.


       dev NAME
              bind the tunnel to the device NAME so that tunneled packets will
              only be routed via this device and will not be able to escape to
              another device when the route to endpoint changes.


       nopmtudisc
              disable Path MTU Discovery on this tunnel.   It  is  enabled  by
              default.   Note  that  a  fixed  ttl  is  incompatible with this
              option: tunnelling with a fixed ttl always makes pmtu discovery.


       key K

       ikey K

       okey K ( only GRE tunnels ) use keyed GRE with key K.  K  is  either  a
              number  or  an  IP  address-like dotted quad.  The key parameter
              sets the key to use in  both  directions.   The  ikey  and  okey
              parameters set different keys for input and output.
              sequencing of outgoing packets.  The iseq flag requires that all
              input packets are serialized.  The seq flag is equivalent to the
              combination iseq oseq.  It isn't work. Don't use it.


       dscp inherit
              ( only IPv6 tunnels ) Inherit DS field between inner  and  outer
              header.


       encaplim ELIM
              (  only IPv6 tunnels ) set a fixed encapsulation limit.  Default
              is 4.


       flowlabel FLOWLABEL
              ( only IPv6 tunnels ) set a fixed flowlabel.


   ip tunnel prl - potential router list (ISATAP only)
       dev NAME
              mandatory device name.


       prl-default ADDR

       prl-nodefault ADDR

       prl-delete ADDR
              Add or delete ADDR as a potential router or default router.


   ip tunnel show - list tunnels
       This command has no arguments.


ip monitor and rtmon - state monitoring
       The ip utility can monitor the state of devices, addresses  and  routes
       continuously.   This  option  has a slightly different format.  Namely,
       the monitor command is the first in  the  command  line  and  then  the
       object list follows:

       ip monitor [ all | LISTofOBJECTS ]

       OBJECT-LIST  is  the  list of object types that we want to monitor.  It
       may contain link, address and route.  If no file argument is given,  ip
       opens  RTNETLINK,  listens  on it and dumps state changes in the format
       described in previous sections.


       If a file name is given, it does not listen on RTNETLINK, but opens the
       file  containing  RTNETLINK  messages  saved in binary format and dumps
       them.  Such a history file can be generated  with  the  rtmon  utility.
       This utility has a command line syntax similar to ip monitor.  Ideally,

ip netns - process network namespace management
       A network namespace is logically another copy  of  the  network  stack,
       with it's own routes, firewall rules, and network devices.

       By   convention   a   named   network   namespace   is   an  object  at
       /var/run/netns/NAME that can be opened.  The file descriptor  resulting
       from opening /var/run/netns/NAME refers to the specified network names-
       pace.  Holding that file descriptor open keeps  the  network  namespace
       alive.   The  file descriptor can be used with the setns(2) system call
       to change the network namespace associated with a task.

       The convention for network namespace aware applications is to look  for
       global  network  configuration  files first in /etc/netns/NAME/ then in
       /etc/.   For  example,   if   you   want   a   different   version   of
       /etc/resolv.conf  for  a network namespace used to isolate your vpn you
       would name it /etc/netns/myvpn/resolv.conf.

       ip netns exec automates handling of this configuration, file convention
       for  network namespace unaware applications, by creating a mount names-
       pace and bind mounting all of the per network namespace configure files
       into their traditional location in /etc.


   ip netns list - show all of the named network namespaces
   ip netns add NAME - create a new named network namespace
   ip netns delete NAME - delete the name of a network namespace
   ip netns exec NAME cmd ... - Run cmd in the named network namespace
ip xfrm - transform configuration
       xfrm  is  an  IP framework for transforming packets (such as encrypting
       their payloads). This framework is used to implement the IPsec protocol
       suite  (with  the  state  object  operating on the Security Association
       Database, and the policy object operating on the Security Policy  Data-
       base). It is also used for the IP Payload Compression Protocol and fea-
       tures of Mobile IPv6.


   ip xfrm state add - add new state into xfrm
   ip xfrm state update - update existing state in xfrm
   ip xfrm state allocspi - allocate an SPI value
   ip xfrm state delete - delete existing state in xfrm
   ip xfrm state get - get existing state in xfrm
   ip xfrm state deleteall - delete all existing state in xfrm
   ip xfrm state list - print out the list of existing state in xfrm
   ip xfrm state flush - flush all state in xfrm
   ip xfrm state count - count all existing state in xfrm
       ID     is specified by a source address, destination address, transform
              protocol XFRM-PROTO, and/or Security Parameter Index SPI.


       XFRM-PROTO
              specifies  a  transform  protocol:  IPsec Encapsulating Security
              Payload (esp), IPsec Authentication Header (ah), IP Payload Com-
              pression  (comp), Mobile IPv6 Type 2 Routing Header (route2), or
              Mobile IPv6 Home Address Option (hao).


       MODE   specifies a mode of operation: IPsec transport mode (transport),
              IPsec  tunnel mode (tunnel), Mobile IPv6 route optimization mode
              (ro), Mobile IPv6 inbound trigger mode  (in_trigger),  or  IPsec
              ESP Bound End-to-End Tunnel Mode (beet).


       FLAG-LIST
              contains  one  or  more  of the following optional flags: noecn,
              decap-dscp, nopmtudisc, wildrecv, icmp, af-unspec, or align4.


       SELECTOR
              selects the traffic that will be controlled by the policy, based
              on  the  source  address,  the  destination address, the network
              device, and/or UPSPEC.


       UPSPEC selects traffic by protocol. For the tcp,  udp,  sctp,  or  dccp
              protocols,  the  source  and  destination port can optionally be
              specified.  For the icmp, ipv6-icmp, or  mobility-header  proto-
              cols,  the  type  and  code numbers can optionally be specified.
              For the gre protocol, the key can optionally be specified  as  a
              dotted-quad  or number.  Other protocols can be selected by name
              or number PROTO.


       LIMIT-LIST
              sets limits in seconds, bytes, or numbers of packets.


       ENCAP  encapsulates packets with protocol espinudp or  espinudp-nonike,
              using  source  port SPORT, destination port DPORT , and original
              address OADDR.


   ip xfrm policy add - add a new policy
   ip xfrm policy update - update an existing policy
   ip xfrm policy delete - delete an existing policy
   ip xfrm policy get - get an existing policy
   ip xfrm policy deleteall - delete all existing xfrm policies
   ip xfrm policy list - print out the list of xfrm policies
   ip xfrm policy flush - flush policies
   ip xfrm policy count - count existing policies
       SELECTOR
              selects the traffic that will be controlled by the policy, based
              on  the  source  address,  the  destination address, the network
              device, and/or UPSPEC.


       UPSPEC selects traffic by protocol. For the tcp,  udp,  sctp,  or  dccp
              protocols,  the  source  and  destination port can optionally be
              specified.  For the icmp, ipv6-icmp, or  mobility-header  proto-

       PTYPE  can be main (default) or sub.


       ACTION can be allow (default) or block.


       PRIORITY
              is a number that defaults to zero.


       FLAG-LIST
              contains one or both of the following optional flags:  local  or
              icmp.


       LIMIT-LIST
              sets limits in seconds, bytes, or numbers of packets.


       TMPL-LIST
              is  a  template  list  specified  using  ID, MODE, REQID, and/or
              LEVEL.


       ID     is specified by a source address, destination address, transform
              protocol XFRM-PROTO, and/or Security Parameter Index SPI.


       XFRM-PROTO
              specifies  a  transform  protocol:  IPsec Encapsulating Security
              Payload (esp), IPsec Authentication Header (ah), IP Payload Com-
              pression  (comp), Mobile IPv6 Type 2 Routing Header (route2), or
              Mobile IPv6 Home Address Option (hao).


       MODE   specifies a mode of operation: IPsec transport mode (transport),
              IPsec  tunnel mode (tunnel), Mobile IPv6 route optimization mode
              (ro), Mobile IPv6 inbound trigger mode  (in_trigger),  or  IPsec
              ESP Bound End-to-End Tunnel Mode (beet).


       LEVEL  can be required (default) or use.


   ip xfrm monitor - state monitoring for xfrm objects
       The xfrm objects to monitor can be optionally specified.


HISTORY
       ip was written by Alexey N. Kuznetsov and added in Linux 2.2.

SEE ALSO
       tc(8)
       IP Command reference ip-cref.ps
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