ip-link(8)
NAME
ip-link - network device configuration
SYNOPSIS
ip [ OPTIONS ] link { COMMAND | help }
OPTIONS := { -V[ersion] | -h[uman-readable] | -s[tatistics] |
-r[esolve] | -f[amily] { inet | inet6 | ipx | dnet | link } |
-o[neline] | -br[ief] }
ip link add [ link DEVICE ] [ name ] NAME
[ txqueuelen PACKETS ]
[ address LLADDR ] [ broadcast LLADDR ]
[ mtu MTU ] [ index IDX ]
[ numtxqueues QUEUE_COUNT ] [ numrxqueues QUEUE_COUNT ]
type TYPE [ ARGS ]
TYPE := [ bridge | bond | can | dummy | hsr | ifb | ipoib | macvlan |
macvtap | vcan | veth | vlan | vxlan | ip6tnl | ipip | sit |
gre | gretap | ip6gre | ip6gretap | vti | nlmon | ipvlan |
lowpan | geneve ]
ip link delete { DEVICE | group GROUP } 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 } |
protodown { 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 ] [ max_tx_rate TXRATE ] [ min_tx_rate TXRATE ] [
spoofchk { on | off } ] [ state { auto | enable | disable} ] |
master DEVICE |
nomaster |
addrgenmode { eui64 | none }
link-netnsid ID }
ip link show [ DEVICE | group GROUP | up | master DEVICE | type TYPE ]
ip link help [ TYPE ]
DESCRIPTION
ip link add - add virtual link
link DEVICE
specifies the physical device to act operate on.
NAME specifies the name of the new virtual device.
TYPE specifies the type of the new device.
Link types:
bridge - Ethernet Bridge device
bond - Bonding device can - Controller Area Network
interface
dummy - Dummy network interface
hsr - High-availability Seamless Redundancy device
ifb - Intermediate Functional Block device
ipoib - IP over Infiniband device
macvlan - Virtual interface base on link layer address
(MAC)
macvtap - Virtual interface based on link layer address
(MAC) and TAP.
vcan - Virtual Controller Area Network interface
veth - Virtual ethernet interface
vlan - 802.1q tagged virtual LAN interface
vxlan - Virtual eXtended LAN
ip6tnl - Virtual tunnel interface IPv4|IPv6 over IPv6
ipip - Virtual tunnel interface IPv4 over IPv4
sit - Virtual tunnel interface IPv6 over IPv4
gre - Virtual tunnel interface GRE over IPv4
gretap - Virtual L2 tunnel interface GRE over IPv4
ip6gre - Virtual tunnel interface GRE over IPv6
ip6gretap - Virtual L2 tunnel interface GRE over IPv6
vti - Virtual tunnel interface
nlmon - Netlink monitoring device
ipvlan - Interface for L3 (IPv6/IPv4) based VLANs
lowpan - Interface for 6LoWPAN (IPv6) over IEEE 802.15.4
/ Bluetooth
geneve - GEneric NEtwork Virtualization Encapsulation
numtxqueues QUEUE_COUNT
specifies the number of transmit queues for new device.
numrxqueues QUEUE_COUNT
specifies the number of receive queues for new device.
index IDX
specifies the desired index of the new virtual device. The link
creation fails, if the index is busy.
VLAN Type Support
For a link of type VLAN the following additional arguments are
supported:
ip link add link DEVICE name NAME type vlan [ protocol
VLAN_PROTO ] id VLANID [ reorder_hdr { on | off } ] [ gvrp { on
| off } ] [ mvrp { on | off } ] [ loose_binding { on | off } ] [
ingress-qos-map QOS-MAP ] [ egress-qos-map QOS-MAP ]
protocol VLAN_PROTO - either 802.1Q or 802.1ad.
id VLANID - specifies the VLAN Identifer to use. Note
that numbers with a leading " 0 " or " 0x " are
interpreted as octal or hexadeimal, respectively.
reorder_hdr { on | off } - specifies whether ethernet
headers are reordered or not (default is on).
If reorder_hdr is on then VLAN header will be not
inserted immediately but only before passing to the
physical device (if this device does not support
VLAN offloading), the similar on the RX direction -
by default the packet will be untagged before being
received by VLAN device. Reordering allows to
accelerate tagging on egress and to hide VLAN header
on ingress so the packet looks like regular Ethernet
packet, at the same time it might be confusing for
packet capture as the VLAN header does not exist
within the packet.
VLAN offloading can be checked by ethtool(8):
ethtool -k <phy_dev> | grep tx-vlan-offload
where <phy_dev> is the physical device to which VLAN
device is bound.
gvrp { on | off } - specifies whether this VLAN should
be registered using GARP VLAN Registration Protocol.
mvrp { on | off } - specifies whether this VLAN should
be registered using Multiple VLAN Registration Protocol.
loose_binding { on | off } - specifies whether the VLAN
device state is bound to the physical device state.
ingress-qos-map QOS-MAP - defines a mapping of VLAN
header prio field to the Linux internal packet priority
on incoming frames. The format is FROM:TO with multiple
mappings separated by spaces.
egress-qos-map QOS-MAP - defines a mapping of Linux
internal packet priority to VLAN header prio field but
for outgoing frames. The format is the same as for
ingress-qos-map.
Linux packet priority can be set by iptables(8):
iptables -t mangle -A POSTROUTING [...] -j
CLASSIFY --set-class 0:4
and this "4" priority can be used in the egress qos
mapping to set VLAN prio "5":
ip link set veth0.10 type vlan egress 4:5
VXLAN Type Support
For a link of type VXLAN the following additional arguments are
supported:
ip link add DEVICE type vxlan id ID [ dev PHYS_DEV ] [ { group
| remote } IPADDR ] [ local IPADDR ] [ ttl TTL ] [ tos TOS ] [
dstport PORT ] [ srcport MIN MAX ] [ [no]learning ] [ [no]proxy
] [ [no]rsc ] [ [no]l2miss ] [ [no]l3miss ] [ [no]udpcsum ] [
[no]udp6zerocsumtx ] [ [no]udp6zerocsumrx ] [ ageing SECONDS ] [
maxaddress NUMBER ] [ gbp ]
id VNI - specifies the VXLAN Network Identifer (or VXLAN
Segment Identifier) to use.
dev PHYS_DEV - specifies the physical device to use for
tunnel endpoint communication.
group IPADDR - specifies the multicast IP address to
join. This parameter cannot be specified with the
remote parameter.
remote IPADDR - specifies the unicast destination IP
address to use in outgoing packets when the destination
link layer address is not known in the VXLAN device
forwarding database. This parameter cannot be specified
with the group parameter.
local IPADDR - specifies the source IP address to use in
outgoing packets.
ttl TTL - specifies the TTL value to use in outgoing
packets.
tos TOS - specifies the TOS value to use in outgoing
packets.
dstport PORT - specifies the UDP destination port to
communicate to the remote VXLAN tunnel endpoint.
srcport MIN MAX - specifies the range of port numbers to
use as UDP source ports to communicate to the remote
VXLAN tunnel endpoint.
[no]learning - specifies if unknown source link layer
addresses and IP addresses are entered into the VXLAN
device forwarding database.
[no]rsc - specifies if route short circuit is turned on.
[no]proxy - specifies ARP proxy is turned on.
[no]l2miss - specifies if netlink LLADDR miss
notifications are generated.
[no]l3miss - specifies if netlink IP ADDR miss
notifications are generated.
[no]udpcsum - specifies if UDP checksum is filled in
[no]udp6zerocsumtx - specifies if UDP checksum is filled
in
[no]udp6zerocsumrx - specifies if UDP checksum is
received
ageing SECONDS - specifies the lifetime in seconds of
FDB entries learnt by the kernel.
maxaddress NUMBER - specifies the maximum number of FDB
entries.
gbp - enables the Group Policy extension (VXLAN-GBP).
Allows to transport group policy context across
VXLAN network peers. If enabled, includes the mark
of a packet in the VXLAN header for outgoing packets
and fills the packet mark based on the information
found in the VXLAN header for incomming packets.
Format of upper 16 bits of packet mark (flags);
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|-|-|-|-|-|-|-|-|-|D|-|-|A|-|-|-|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
D := Don't Learn bit. When set, this bit indicates
that the egress VTEP MUST NOT learn the source
address of the encapsulated frame.
A := Indicates that the group policy has already
been applied to this packet. Policies MUST NOT be
applied by devices when the A bit is set.
Format of lower 16 bits of packet mark (policy ID):
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Group Policy ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Example:
iptables -A OUTPUT [...] -j MARK --set-mark
0x800FF
GRE, IPIP, SIT Type Support
For a link of types GRE/IPIP/SIT the following additional
arguments are supported:
ip link add DEVICE type { gre | ipip | sit } remote ADDR local
ADDR [ encap { fou | gue | none } ] [ encap-sport { PORT | auto
} ] [ encap-dport PORT ] [ [no]encap-csum ] [ [no]encap-
remcsum ]
remote ADDR - specifies the remote address of the
tunnel.
local ADDR - specifies the fixed local address for
tunneled packets. It must be an address on another
interface on this host.
encap { fou | gue | none } - specifies type of secondary
UDP encapsulation. "fou" indicates Foo-Over-UDP, "gue"
indicates Generic UDP Encapsulation.
encap-sport { PORT | auto } - specifies the source port
in UDP encapsulation. PORT indicates the port by
number, "auto" indicates that the port number should be
chosen automatically (the kernel picks a flow based on
the flow hash of the encapsulated packet).
[no]encap-csum - specifies if UDP checksums are enabled
in the secondary encapsulation.
[no]encap-remcsum - specifies if Remote Checksum Offload
is enabled. This is only applicable for Generic UDP
Encapsulation.
IP6GRE/IP6GRETAP Type Support
For a link of type IP6GRE/IP6GRETAP the following additional
arguments are supported:
ip link add DEVICE type { ip6gre | ip6gretap } remote ADDR
local ADDR [ [i|o]seq] ] [ [i|o]key KEY ] [ [i|o]csum ] [
hoplimit TTL ] [ encaplimit ELIM ] [ tclass TCLASS ] [ flowlabel
FLOWLABEL ] [ dscp inherit ] [ dev PHYS_DEV ]
remote ADDR - specifies the remote IPv6 address of the
tunnel.
local ADDR - specifies the fixed local IPv6 address for
tunneled packets. It must be an address on another
interface on this host.
[i|o]seq - serialize packets. The oseq flag enables
sequencing of outgoing packets. The iseq flag requires
that all input packets are serialized.
[i|o]key KEY - use keyed GRE with key KEY. KEY is either
a number or an IPv4 address-like dotted quad. The key
parameter specifies the same key to use in both
directions. The ikey and okey parameters specify
different keys for input and output.
[i|o]csum - 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 icsum ocsum.
hoplimit TTL - specifies Hop Limit value to use in
outgoing packets.
encaplimit ELIM - specifies a fixed encapsulation limit.
Default is 4.
flowlabel FLOWLABEL - specifies a fixed flowlabel.
tclass TCLASS - specifies the traffic class field on
tunneled packets, which can be specified as either a
two-digit hex value (e.g. c0) or a predefined string
(e.g. internet). The value inherit causes the field to
be copied from the original IP header. The values
inherit/STRING or inherit/00..ff will set the field to
STRING or 00..ff when tunneling non-IP packets. The
default value is 00.
IPoIB Type Support
For a link of type IPoIB the following additional arguments are
supported:
ip link add DEVICE name NAME type ipoib [ pkey PKEY ] [mode MODE
]
pkey PKEY - specifies the IB P-Key to use.
mode MODE - specifies the mode (datagram or connected)
to use.
GENEVE Type Support
For a link of type GENEVE the following additional arguments are
supported:
ip link add DEVICE type geneve id ID remote IPADDR [ ttl TTL ] [
tos TOS ]
id VNI - specifies the Virtual Network Identifer to use.
remote IPADDR - specifies the unicast destination IP
address to use in outgoing packets.
ttl TTL - specifies the TTL value to use in outgoing
packets.
tos TOS - specifies the TOS value to use in outgoing
packets.
MACVLAN and MACVTAP Type Support
For a link of type MACVLAN or MACVTAP the following additional
arguments are supported:
ip link add link DEVICE name NAME type { macvlan | macvtap }
mode { private | vepa | bridge | passthru [ nopromisc ] }
type { macvlan | macvtap } - specifies the link type to
use. macvlan creates just a virtual interface, while
macvtap in addition creates a character device /dev/tapX
to be used just like a tuntap device.
mode private - Do not allow communication between
macvlan instances on the same physical interface, even
if the external switch supports hairpin mode.
mode vepa - Virtual Ethernet Port Aggregator mode. Data
from one macvlan instance to the other on the same
physical interface is transmitted over the physical
interface. Either the attached switch needs to support
hairpin mode, or there must be a TCP/IP router
forwarding the packets in order to allow communication.
This is the default mode.
mode bridge - In bridge mode, all endpoints are directly
connected to each other, communication is not redirected
through the physical interface's peer.
mode passthru [ nopromisc ] - This mode gives more power
to a single endpoint, usually in macvtap mode. It is not
allowed for more than one endpoint on the same physical
interface. All traffic will be forwarded to this
endpoint, allowing virtio guests to change MAC address
or set promiscuous mode in order to bridge the interface
or create vlan interfaces on top of it. By default, this
mode forces the underlying interface into promiscuous
mode. Passing the nopromisc flag prevents this, so the
promisc flag may be controlled using standard tools.
ip link delete - delete virtual link
dev DEVICE
specifies the virtual device to act operate on.
group GROUP
specifies the group of virtual links to delete. Group 0 is not
allowed to be deleted since it is the default group.
type TYPE
specifies the type of the device.
ip link set - change device attributes
dev DEVICE
DEVICE specifies network device to operate on. When configuring
SR-IOV Virtual Function (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.
protodown on or protodown off
change the PROTODOWN state on the device. Indicates that a
protocol error has been detected on the port. Switch drivers can
react to this error by doing a phys down on the switch port.
dynamic on or dynamic off
change the DYNAMIC flag on the device. Indicates that address
can change when interface goes down (currently NOT used by the
Linux).
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 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 NETNSNAME | PID
move the device to the network namespace associated with name
NETNSNAME or process PID.
Some devices are not allowed to change network namespace:
loopback, bridge, ppp, wireless. These are network namespace
local devices. In such case ip tool will return "Invalid
argument" error. It is possible to find out if device is local
to a single network namespace by checking netns-local flag in
the output of the ethtool:
ethtool -k DEVICE
To change network namespace for wireless devices the iw tool can
be used. But it allows to change network namespace only for
physical devices and by process PID.
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
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. vf parameter must be specified.
Please use new API max_tx_rate option instead.
max_tx_rate TXRATE - change the allowed maximum transmit
bandwidth, in Mbps, for the specified VF. vf parameter
must be specified.
min_tx_rate TXRATE - change the allowed minimum transmit
bandwidth, in Mbps, for the specified VF. Minimum
TXRATE should be always <= Maximum TXRATE. vf parameter
must be specified.
spoofchk on|off - turn packet spoof checking on or off
for the specified VF.
state auto|enable|disable - set the virtual link state
as seen by the specified VF. Setting to auto means a
reflection of the PF link state, enable lets the VF to
communicate with other VFs on this host even if the PF
link state is down, disable causes the HW to drop any
packets sent by the VF.
master DEVICE
set master device of the device (enslave device).
nomaster
unset master device of the device (release device).
addrgenmode eui64 or addrgenmode none
set IPv6 address generation mode
link-netnsid
set peer netnsid for a cross-netns interface
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.
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.
master DEVICE
DEVICE specifies the master device which enslaves devices to
show.
type TYPE
TYPE specifies the type of devices to show.
The show command has additional formatting options:
-s, -stats, -statistics
output more statistics about packet usage.
-d, -details
output more detailed information.
-h, -human, -human-readable
output statistics with human readable values number
followed by suffix
-iec print human readable rates in IEC units (ie. 1K = 1024).
ip link help - display help
TYPE specifies which help of link type to dislpay.
GROUP
may be a number or a string from the file /etc/iproute2/group which can
be manually filled.
EXAMPLES
ip link show
Shows the state of all network interfaces on the system.
ip link show type bridge
Shows the bridge devices.
ip link show type vlan
Shows the vlan devices.
ip link show master br0
Shows devices enslaved by br0
ip link set dev ppp0 mtu 1400
Change the MTU the ppp0 device.
ip link add link eth0 name eth0.10 type vlan id 10
Creates a new vlan device eth0.10 on device eth0.
ip link delete dev eth0.10
Removes vlan device.
ip link help gre
Display help for the gre link type.
ip link add name tun1 type ipip remote 192.168.1.1 local 192.168.1.2
ttl 225 encap gue encap-sport auto encap-dport 5555 encap-csum encap-
remcsum
Creates an IPIP that is encapsulated with Generic UDP
Encapsulation, and the outer UDP checksum and remote checksum
offload are enabled.
ip link add link wpan0 lowpan0 type lowpan
Creates a 6LoWPAN interface named lowpan0 on the underlying IEEE
802.15.4 device wpan0.
SEE ALSO
ip(8), ip-netns(8), ethtool(8), iptables(8)
AUTHOR
Original Manpage by Michail Litvak <mci@owl.openwall.com>
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