SYNOPSIS
ip link
{ COMMAND |
help }
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 } ]
[ dynamic { on | off } ]
[ multicast { on | off } ]
[ allmulticast { on | off } ]
[ promisc { on | off } ]
[ protodown { on | off } ]
[ trailers { on | off } ]
[ txqueuelen
PACKETS ]
[ name
NEWNAME ]
[ address
LLADDR ]
[ broadcast
LLADDR ]
[ mtu
MTU ]
[ netns {
PID | NETNSNAME } ]
[ link-netnsid
ID ]
[ 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 } ]
[ trust { on | off } ] ]
[ master
DEVICE ]
[ nomaster ]
[ addrgenmode { eui64 | none | stable_secret | random } ]
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 | any } ] [ ttl TTL ] [ tos TOS ] [ flowlabel FLOWLABEL ] [ 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.
flowlabel FLOWLABEL - specifies the flow label 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 calculated for transmitted packets over IPv4.
[no]udp6zerocsumtx - skip UDP checksum calculation for transmitted packets over IPv6.
[no]udp6zerocsumrx - allow incoming UDP packets over IPv6 with zero checksum field.
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 ] [ flowlabel FLOWLABEL ]
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.
flowlabel FLOWLABEL - specifies the flow label 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.
trust on|off - trust the specified VF user. This enables that VF user can set a specific feature which may impact security and/or performance. (e.g. VF multicast promiscuous mode)
- master DEVICE
-
set master device of the device (enslave device).
- nomaster
-
unset master device of the device (release device).
- addrgenmode eui64|none|stable_secret|random
-
set the IPv6 address generation mode
eui64 - use a Modified EUI-64 format interface identifier
none - disable automatic address generation
stable_secret - generate the interface identifier based on a preset /proc/sys/net/ipv6/conf/{default,DEVICE}/stable_secret
random - like stable_secret, but auto-generate a new random secret if none is set
- 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.