Man page 8 : ip

OBJECT

link

    - network device.

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.

xfrm

    - framework for IPsec protocol.

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

R 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 commands 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,

R

• link DEVICE
      specifies the physical device to act operate on. NAMEspecifies the name of the new virtual device. TYPEspecifies the type of the new device.
  
  Link types:

vlan - 802.1q tagged virrtual LAN interface

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

can - Controller Area Network interface

DEVICEspecifies the virtual device to act operate on. TYPEspecifies the type of the device.

• dev DEVICE
      specifies the physical device to act operate on.

• dev DEVICE
      .I 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.

R up

    change the state of the device to

UP or

R

R

    change the

NOARP flag on the device.

R

    change the

MULTICAST flag on the device.

R

    change the

DYNAMIC flag on the device.

• name NAME
      change the name of the device. This operation is not recommended if the device is running or has some addresses already configured.
• txqueuelen NUMBER
• txqlen NUMBER
      change the transmit queue length of the device.
• mtu NUMBER
      change the MTUof 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".
• alias NAME
      give the device a symbolic name for easy reference.
• vf NUM
      specify a Virtual Function device to be configured. The associated PF device must be specified using the

dev parameter. mac LLADDRESS - change the station address for the specified 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. Setting this parameter to 0 disables VLAN tagging and filtering. 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 VLAN tag. If not specified, the value is assumed to be 0. Both the

vf and

vlan parameters must be specified. Setting both

vlan and

qos as 0 disables VLAN tagging and filtering for the VF.

rate TXRATE - change the allowed transmit bandwidth, in Mbps, for the specified VF. Setting this parameter to 0 disables rate limiting. The

vf parameter must be specified.

Warning: If multiple parameter changes are requested,

ip aborts immediately 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.

• dev NAME (default)
      .I NAME specifies the network device to show. If this argument is omitted all devices are listed.

up

    only display running interfaces.

• 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 ADDRESSmay 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. Again, the ADDRESSmay be followed by a slash and a decimal number, encoding the network prefix length. If a peer address is specified, the local address cannot have a prefix length. The network prefix is associated with the peer rather than with the local address.
• broadcast ADDRESS
      the broadcast address on the interface.
  
  It is possible to use the special symbols

'+' and

'-' instead of the broadcast address. In this case, the broadcast address is derived by setting/resetting the host bits of the interface prefix.

• 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 available scopes are listed in file

R Predefined 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.

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.

• 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" . PATTERNis a usual shell style pattern.

R dynamic

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

tentative

    (IPv6 only) only list addresses which have not yet passed duplicate address detection.

deprecated

    (IPv6 only) only list deprecated addresses.

dadfailed

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

temporary

    (IPv6 only) only list temporary addresses.

R primary

    only list primary (or secondary) 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.

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.

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 command show contents of address labels.

the command flushes the contents of address labels and it does not restore default settings.

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. LLADDRESScan also be

R

• nud NUD_STATE
      the state of the neighbour entry.

nud is an abbreviation for 'Neigh bour 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.

This command invalidates a neighbour entry.

The arguments are the same as with

R except that

lladdr and

nud are ignored.

Warning: Attempts to delete or manually change a

noarp entry created by the kernel may result in unpredictable behaviour. Particularly, the kernel may try to resolve this address even on a

NOARP interface or if the address is multicast or broadcast.

This commands displays neighbour tables.

• 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_STATEtakes values 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

R

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

R

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.

• to TYPE PREFIX (default)
      the destination prefix of the route. If TYPEis omitted,

ip assumes type

R Other values of TYPEare listed above. PREFIXis 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

R

• 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. TOSis either an 8 bit hexadecimal number or an identifier from

R

• metric NUMBER
• preference NUMBER
      the preference value of the route. NUMBERis an arbitrary 32bit number.
• table TABLEID
      the table to add this route to. TABLEIDmay be a number or a string from the file

R If this parameter is omitted,

ip assumes the

main table, with the exception of

R local routes, which are put into the

local table by default.

• dev NAME
      the output device name.
• via ADDRESS
      the address of the nexthop router. Actually, the sense of this field depends on the route type. For normal

unicast routes it is either the true next hop router or, if it is a direct route installed in BSD compatibility mode, it can be a local address of the interface. For NAT routes it is the first address of the block of translated IP destinations.

• src ADDRESS
      the source address to prefer when sending to the destinations covered by the route prefix.
• realm REALMID
      the realm to which this route is assigned. REALMIDmay be a number or a string from the file

R

• 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 discovery 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 routing code to maintain compatability with previous releases. Otherwise if a suffix of s, sec or secs is used to specify seconds; ms, msec or msecs to specify milliseconds; us, usec or usecs to specify microseconds; ns, nsec or nsecs to specify nanoseconds; j, hz or jiffies to specify jiffies, the value is converted to what the routing code expects.
• 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 destination. Actual window size is this value multiplied by the MSS (``Maximal Segment Size'') for same connection. The default is zero, meaning to use the values specified in RFC2414.
• initrwnd NUMBER (2.6.33+ only)
      the initial receive window size for connections to this destination. Actual window size is this value multiplied by the MSS of the connection. The default value is zero, meaning to use Slow Start value.
• advmss NUMBER (2.3.15+ only)
      the MSS ('Maximal Segment Size') to advertise to these destinations 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

R

• nexthop NEXTHOP
      the nexthop of a multipath route. NEXTHOPis 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 multipath route reflecting its relative bandwidth or quality.
• scope SCOPE_VAL
      the scope of the destinations covered by the route prefix. SCOPE_VALmay be a number or a string from the file

R If this parameter is omitted,

ip assumes scope

global for all gatewayed

unicast routes, scope

link for direct

R unicast routes and scope

R host routes.

• protocol RTPROTO
      the routing protocol identifier of this route. RTPROTOmay be a number or a string from the file

R 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 redirect.

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.

static - the route was installed by the administrator to override dynamic routing. Routing daemon will respect them and, probably, even advertise them to its peers.

ra - the route was installed by Router Discovery protocol.

The rest of the values are not reserved and the administrator is 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 del has the same arguments as

R but their semantics 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.

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. SELECTORconsists 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 PREFIX "." 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

R table main TABLEIDmay 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

R

• from SELECTOR
      the same syntax as for

R to but it binds the source address range rather than destinations. Note that the

from option only works with cloned routes.

• protocol RTPROTO
      only list routes of this protocol.
• 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 PREFIX "."
• src PREFIX
      only list routes with preferred source addresses selected by PREFIX "."
• realm REALMID
• realms FROMREALM/TOREALM
      only list routes with these realms.

this command flushes routes selected by some criteria.

The arguments have the same syntax and semantics as the arguments of

R 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 subsection.

this command gets a single route to a destination and prints its contents exactly as the kernel sees it.

• to ADDRESS (default)
      the destination address.
• from ADDRESS
      the source address.
• tos TOS
• dsfield TOS
      the Type Of Service.
• iif NAME
      the device from which this packet is expected to arrive.
• 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

R

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

R 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.

• type TYPE (default)
      the type of this rule. The list of valid types was given in the previous subsection.
• from PREFIX
      select the source prefix to match.
• to PREFIX
      select the destination prefix to match.
• iif NAME
      select the incoming device to match. If the interface is loopback, the rule only matches packets originating from this host. This means that you may create separate routing tables for forwarded 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 uniquepriority 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 TOis 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 ADDRESSmay 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.

Warning: Changes to the RPDB made with these commands do not become active immediately. It is assumed that after a script finishes a batch of updates, it flushes the routing cache with

R

This command has no arguments.

This command has no arguments. The options list or lst are synonyms with show.

• dev NAME (default)
      the device name.

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.

• 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.

• name NAME (default)
      select the tunnel device name.
• mode MODE
      set the tunnel mode. Available modes depend on the encapsulating address family.
  Modes for IPv4 encapsulation available:

R ipip
Modes for IPv6 encapsulation available:

R ip6ip6

• 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 Non tunneled packets. Nis 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:

R The default value for IPv6 tunnels is:

R

• tos T
• dsfield T
• tclass T
      set a fixed TOS (or traffic class in IPv6) Ton tunneled packets. The default value is:

R

• dev NAME
      bind the tunnel to the device NAMEso 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

R ikey parameters set different keys for input and output.

R csum

     ( " only GRE tunnels " ) generate/require checksums for tunneled packets. The

ocsum flag calculates checksums for outgoing packets. The

icsum flag requires that all input packets have the correct checksum. The

csum flag is equivalent to the combination

R

R seq

     ( " only GRE tunnels " ) serialize packets. The

oseq flag enables sequencing of outgoing packets. The

iseq flag requires that all input packets are serialized. The

seq flag is equivalent to the combination

R

It isn't work. Don't use it.

R

     ( " 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.

• 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.

This command has no arguments.

• MODE
      is set as default to

R transport but it could be set to

R tunnel

• FLAG-LIST
      contains one or more flags.
• FLAG
      could be set to

R noecn

• ENCAP
      encapsulation is set to encapsulation type ENCAP-TYPE ", source port " SPORT ", destination port " DPORT " and " OADDR "."
• ENCAP-TYPE
      could be set to

R espinudp

• ALGO-LIST
      contains one or more algorithms ALGOwhich depend on the type of algorithm set by ALGO_TYPE "." It can be used these algoritms

R enc

It can be flush

R all policies or only those specified with

R ptype

• dir DIR
      directory could be one of these:

R

• SELECTOR
      selects for which addresses will be set up the policy. The selector is defined by source and destination address.
• UPSPEC
      is defined by source port

R sport destination port

R dport as number and

code also number.

• dev DEV
      specify network device.
• index INDEX
      the number of indexed policy.
• ptype PTYPE
      type is set as default on

R could be switch on

R

• action ACTION
      is set as default on

R It could be switch on

R

• priority PRIORITY
      priority is a number. Default priority is set on zero.
• LIMIT-LIST
      limits are set in seconds, bytes or numbers of packets.
• TMPL-LIST
      template list is based on ID ","

R mode

• ID
      is specified by source address, destination address, protoand value of spi "."
• XFRM_PROTO
      values:

R esp

• MODE
      is set as default on

R transport but it could be set on

R tunnel

• LEVEL
      is set as default on

R required and the other choice is

R use

• UPSPEC
      is specified by

R sport

R dport and

code (NUMBER).

The

xfrm monitor can monitor the policies for all objects or defined group of them.