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SYSTEMD.NETDEV(5) systemd.network SYSTEMD.NETDEV(5)
systemd.netdev - Virtual Network Device configuration
netdev.netdev
A plain ini-style text file that encodes configuration about a
virtual network device, used by systemd-networkd(8). See
systemd.syntax(7) for a general description of the syntax.
The main Virtual Network Device file must have the extension
.netdev; other extensions are ignored. Virtual network devices are
created as soon as systemd-networkd is started if possible. If a
netdev with the specified name already exists, systemd-networkd
will try to update the config if the kind of the existing netdev
is equivalent to the requested one, otherwise (e.g. when bridge
device foo exists but bonding device with the same name is
configured in a .netdev file) use the existing netdev as-is rather
than replacing with the requested netdev. Note, several settings
(e.g. vlan ID) cannot be changed after the netdev is created. To
change such settings, it is necessary to first remove the existing
netdev, and then run networkctl reload command or restart
systemd-networkd. See also networkctl(1).
The .netdev files are read from the files located in the system
network directory /usr/lib/systemd/network and
/usr/local/lib/systemd/network, the volatile runtime network
directory /run/systemd/network and the local administration
network directory /etc/systemd/network. All configuration files
are collectively sorted and processed in alphanumeric order,
regardless of the directories in which they live. However, files
with identical filenames replace each other. It is recommended
that each filename is prefixed with a number smaller than "70"
(e.g. 10-vlan.netdev). Otherwise, .netdev files generated by
systemd-network-generator.service(8) may take precedence over user
configured files. Files in /etc/ have the highest priority, files
in /run/ take precedence over files with the same name in
/usr/lib/. This can be used to override a system-supplied
configuration file with a local file if needed. As a special case,
an empty file (file size 0) or symlink with the same name pointing
to /dev/null disables the configuration file entirely (it is
"masked").
Along with the netdev file foo.netdev, a "drop-in" directory
foo.netdev.d/ may exist. All files with the suffix ".conf" from
this directory will be merged in the alphanumeric order and parsed
after the main file itself has been parsed. This is useful to
alter or add configuration settings, without having to modify the
main configuration file. Each drop-in file must have appropriate
section headers.
In addition to /etc/systemd/network, drop-in ".d" directories can
be placed in /usr/lib/systemd/network or /run/systemd/network
directories. Drop-in files in /etc/ take precedence over those in
/run/ which in turn take precedence over those in /usr/lib/.
Drop-in files under any of these directories take precedence over
the main netdev file wherever located. (Of course, since /run/ is
temporary and /usr/lib/ is for vendors, it is unlikely drop-ins
should be used in either of those places.)
The following kinds of virtual network devices may be configured
in .netdev files:
Table 1. Supported kinds of virtual network devices
┌───────────┬──────────────────────────┐
│ Kind │ Description │
├───────────┼──────────────────────────┤
│ bond │ A bond device is an │
│ │ aggregation of all its │
│ │ slave devices. See Linux │
│ │ Ethernet Bonding Driver │
│ │ HOWTO[1] for details. │
├───────────┼──────────────────────────┤
│ bridge │ A bridge device is a │
│ │ software switch, and │
│ │ each of its slave │
│ │ devices and the bridge │
│ │ itself are ports of the │
│ │ switch. │
├───────────┼──────────────────────────┤
│ dummy │ A dummy device drops all │
│ │ packets sent to it. │
├───────────┼──────────────────────────┤
│ gre │ A Level 3 GRE tunnel │
│ │ over IPv4. See RFC │
│ │ 2784[2] for details. │
│ │ Name "gre0" should not │
│ │ be used, as the kernel │
│ │ creates a device with │
│ │ this name when the │
│ │ corresponding kernel │
│ │ module is loaded. │
├───────────┼──────────────────────────┤
│ gretap │ A Level 2 GRE tunnel │
│ │ over IPv4. Name │
│ │ "gretap0" should not be │
│ │ used, as the kernel │
│ │ creates a device with │
│ │ this name when the │
│ │ corresponding kernel │
│ │ module is loaded. │
├───────────┼──────────────────────────┤
│ erspan │ ERSPAN mirrors traffic │
│ │ on one or more source │
│ │ ports and delivers the │
│ │ mirrored traffic to one │
│ │ or more destination │
│ │ ports on another switch. │
│ │ The traffic is │
│ │ encapsulated in generic │
│ │ routing encapsulation │
│ │ (GRE) and is therefore │
│ │ routable across a layer │
│ │ 3 network between the │
│ │ source switch and the │
│ │ destination switch. Name │
│ │ "erspan0" should not be │
│ │ used, as the kernel │
│ │ creates a device with │
│ │ this name when the │
│ │ corresponding kernel │
│ │ module is loaded. │
├───────────┼──────────────────────────┤
│ ip6gre │ A Level 3 GRE tunnel │
│ │ over IPv6. │
├───────────┼──────────────────────────┤
│ ip6tnl │ An IPv4 or IPv6 tunnel │
│ │ over IPv6 │
├───────────┼──────────────────────────┤
│ ip6gretap │ A Level 2 GRE tunnel │
│ │ over IPv6. │
├───────────┼──────────────────────────┤
│ ipip │ An IPv4 over IPv4 │
│ │ tunnel. │
├───────────┼──────────────────────────┤
│ ipvlan │ An IPVLAN device is a │
│ │ stacked device which │
│ │ receives packets from │
│ │ its underlying device │
│ │ based on IP address │
│ │ filtering. │
├───────────┼──────────────────────────┤
│ ipvtap │ An IPVTAP device is a │
│ │ stacked device which │
│ │ receives packets from │
│ │ its underlying device │
│ │ based on IP address │
│ │ filtering and can be │
│ │ accessed using the tap │
│ │ user space interface. │
├───────────┼──────────────────────────┤
│ macvlan │ A macvlan device is a │
│ │ stacked device which │
│ │ receives packets from │
│ │ its underlying device │
│ │ based on MAC address │
│ │ filtering. │
├───────────┼──────────────────────────┤
│ macvtap │ A macvtap device is a │
│ │ stacked device which │
│ │ receives packets from │
│ │ its underlying device │
│ │ based on MAC address │
│ │ filtering. │
├───────────┼──────────────────────────┤
│ sit │ An IPv6 over IPv4 │
│ │ tunnel. │
├───────────┼──────────────────────────┤
│ tap │ A persistent Level 2 │
│ │ tunnel between a network │
│ │ device and a device │
│ │ node. │
├───────────┼──────────────────────────┤
│ tun │ A persistent Level 3 │
│ │ tunnel between a network │
│ │ device and a device │
│ │ node. │
├───────────┼──────────────────────────┤
│ veth │ An Ethernet tunnel │
│ │ between a pair of │
│ │ network devices. │
├───────────┼──────────────────────────┤
│ vlan │ A VLAN is a stacked │
│ │ device which receives │
│ │ packets from its │
│ │ underlying device based │
│ │ on VLAN tagging. See │
│ │ IEEE 802.1Q[3] for │
│ │ details. │
├───────────┼──────────────────────────┤
│ vti │ An IPv4 over IPSec │
│ │ tunnel. │
├───────────┼──────────────────────────┤
│ vti6 │ An IPv6 over IPSec │
│ │ tunnel. │
├───────────┼──────────────────────────┤
│ vxlan │ A virtual extensible LAN │
│ │ (vxlan), for connecting │
│ │ Cloud computing │
│ │ deployments. │
├───────────┼──────────────────────────┤
│ geneve │ A GEneric NEtwork │
│ │ Virtualization │
│ │ Encapsulation (GENEVE) │
│ │ netdev driver. │
├───────────┼──────────────────────────┤
│ hsr │ A High-availability │
│ │ Seamless Redundancy │
│ │ (HSR) or Parallel │
│ │ Redundancy Protocol │
│ │ (PRP) interface. HSR and │
│ │ PRP are two protocols │
│ │ defined by the IEC │
│ │ 62439-3 standard, │
│ │ providing seamless │
│ │ failover against failure │
│ │ of any single network │
│ │ component. │
├───────────┼──────────────────────────┤
│ l2tp │ A Layer 2 Tunneling │
│ │ Protocol (L2TP) is a │
│ │ tunneling protocol used │
│ │ to support virtual │
│ │ private networks (VPNs) │
│ │ or as part of the │
│ │ delivery of services by │
│ │ ISPs. It does not │
│ │ provide any encryption │
│ │ or confidentiality by │
│ │ itself │
├───────────┼──────────────────────────┤
│ macsec │ Media Access Control │
│ │ Security (MACsec) is an │
│ │ 802.1AE IEEE │
│ │ industry-standard │
│ │ security technology that │
│ │ provides secure │
│ │ communication for all │
│ │ traffic on Ethernet │
│ │ links. MACsec provides │
│ │ point-to-point security │
│ │ on Ethernet links │
│ │ between directly │
│ │ connected nodes and is │
│ │ capable of identifying │
│ │ and preventing most │
│ │ security threats. │
├───────────┼──────────────────────────┤
│ vrf │ A Virtual Routing and │
│ │ Forwarding (VRF[4]) │
│ │ interface to create │
│ │ separate routing and │
│ │ forwarding domains. │
├───────────┼──────────────────────────┤
│ vcan │ The virtual CAN driver │
│ │ (vcan). Similar to the │
│ │ network loopback │
│ │ devices, vcan offers a │
│ │ virtual local CAN │
│ │ interface. │
├───────────┼──────────────────────────┤
│ vxcan │ The virtual CAN tunnel │
│ │ driver (vxcan). Similar │
│ │ to the virtual ethernet │
│ │ driver veth, vxcan │
│ │ implements a local CAN │
│ │ traffic tunnel between │
│ │ two virtual CAN network │
│ │ devices. When creating a │
│ │ vxcan, two vxcan devices │
│ │ are created as pair. │
│ │ When one end receives │
│ │ the packet it appears on │
│ │ its pair and vice versa. │
│ │ The vxcan can be used │
│ │ for cross namespace │
│ │ communication. │
├───────────┼──────────────────────────┤
│ wireguard │ WireGuard Secure Network │
│ │ Tunnel. │
├───────────┼──────────────────────────┤
│ nlmon │ A Netlink monitor │
│ │ device. Use an nlmon │
│ │ device when you want to │
│ │ monitor system Netlink │
│ │ messages. │
├───────────┼──────────────────────────┤
│ fou │ Foo-over-UDP tunneling. │
├───────────┼──────────────────────────┤
│ xfrm │ A virtual tunnel │
│ │ interface like vti/vti6 │
│ │ but with several │
│ │ advantages. │
├───────────┼──────────────────────────┤
│ ifb │ The Intermediate │
│ │ Functional Block (ifb) │
│ │ pseudo network interface │
│ │ acts as a QoS │
│ │ concentrator for │
│ │ multiple different │
│ │ sources of traffic. │
├───────────┼──────────────────────────┤
│ bareudp │ Bare UDP tunnels provide │
│ │ a generic L3 │
│ │ encapsulation support │
│ │ for tunnelling different │
│ │ L3 protocols like MPLS, │
│ │ IP etc. inside of a UDP │
│ │ tunnel. │
├───────────┼──────────────────────────┤
│ batadv │ B.A.T.M.A.N. Advanced[5] │
│ │ is a routing protocol │
│ │ for multi-hop mobile │
│ │ ad-hoc networks which │
│ │ operates on layer 2. │
├───────────┼──────────────────────────┤
│ ipoib │ An IP over Infiniband │
│ │ subinterface. │
├───────────┼──────────────────────────┤
│ wlan │ A virtual wireless │
│ │ network (WLAN) │
│ │ interface. │
└───────────┴──────────────────────────┘
A virtual network device is only created if the [Match] section
matches the current environment, or if the section is empty. The
following keys are accepted:
Host=
Matches against the hostname or machine ID of the host. See
ConditionHost= in systemd.unit(5) for details. When prefixed
with an exclamation mark ("!"), the result is negated. If an
empty string is assigned, the previously assigned value is
cleared.
Added in version 211.
Virtualization=
Checks whether the system is executed in a virtualized
environment and optionally test whether it is a specific
implementation. See ConditionVirtualization= in
systemd.unit(5) for details. When prefixed with an exclamation
mark ("!"), the result is negated. If an empty string is
assigned, the previously assigned value is cleared.
Added in version 211.
KernelCommandLine=
Checks whether a specific kernel command line option is set.
See ConditionKernelCommandLine= in systemd.unit(5) for
details. When prefixed with an exclamation mark ("!"), the
result is negated. If an empty string is assigned, the
previously assigned value is cleared.
Added in version 211.
KernelVersion=
Checks whether the kernel version (as reported by uname -r)
matches a certain expression. See ConditionKernelVersion= in
systemd.unit(5) for details. When prefixed with an exclamation
mark ("!"), the result is negated. If an empty string is
assigned, the previously assigned value is cleared.
Added in version 237.
Version=
Checks whether a software version matches a certain
expression. See ConditionVersion= in systemd.unit(5) for
details. When prefixed with an exclamation mark ("!"), the
result is negated. If an empty string is assigned, the
previously assigned value is cleared.
Added in version 258.
Credential=
Checks whether the specified credential was passed to the
systemd-udevd.service service. See System and Service
Credentials[6] for details. When prefixed with an exclamation
mark ("!"), the result is negated. If an empty string is
assigned, the previously assigned value is cleared.
Added in version 252.
Architecture=
Checks whether the system is running on a specific
architecture. See ConditionArchitecture= in systemd.unit(5)
for details. When prefixed with an exclamation mark ("!"), the
result is negated. If an empty string is assigned, the
previously assigned value is cleared.
Added in version 211.
Firmware=
Checks whether the system is running on a machine with the
specified firmware. See ConditionFirmware= in systemd.unit(5)
for details. When prefixed with an exclamation mark ("!"), the
result is negated. If an empty string is assigned, the
previously assigned value is cleared.
Added in version 249.
The [NetDev] section accepts the following keys:
Description=
A free-form description of the netdev.
Added in version 215.
Name=
The interface name used when creating the netdev. This setting
is compulsory.
Added in version 211.
Kind=
The netdev kind. This setting is compulsory. See the
"Supported netdev kinds" section for the valid keys.
Added in version 211.
MTUBytes=
The maximum transmission unit in bytes to set for the device.
The usual suffixes K, M, G are supported and are understood to
the base of 1024. For "tun" or "tap" devices, MTUBytes=
setting is not currently supported in [NetDev] section. Please
specify it in [Link] section of corresponding
systemd.network(5) files.
Added in version 215.
MACAddress=
Specifies the MAC address to use for the device, or takes the
special value "none". When "none", systemd-networkd does not
request the MAC address for the device, and the kernel will
assign a random MAC address. For "tun", "tap", or "l2tp"
devices, the MACAddress= setting in the [NetDev] section is
not supported and will be ignored. Please specify it in the
[Link] section of the corresponding systemd.network(5) file.
If this option is not set, "vlan" device inherits the MAC
address of the master interface. For other kind of netdevs, if
this option is not set, then the MAC address is generated
based on the interface name and the machine-id(5).
Note, even if "none" is specified, systemd-udevd will assign
the persistent MAC address for the device, as 99-default.link
has MACAddressPolicy=persistent. So, it is also necessary to
create a custom .link file for the device, if the MAC address
assignment is not desired.
Added in version 215.
The [Bridge] section only applies for netdevs of kind "bridge",
and accepts the following keys:
HelloTimeSec=
HelloTimeSec specifies the number of seconds between two hello
packets sent out by the root bridge and the designated
bridges. Hello packets are used to communicate information
about the topology throughout the entire bridged local area
network.
Added in version 227.
MaxAgeSec=
MaxAgeSec specifies the number of seconds of maximum message
age. If the last seen (received) hello packet is more than
this number of seconds old, the bridge in question will start
the takeover procedure in attempt to become the Root Bridge
itself.
Added in version 227.
ForwardDelaySec=
ForwardDelaySec specifies the number of seconds spent in each
of the Listening and Learning states before the Forwarding
state is entered.
Added in version 227.
AgeingTimeSec=
This specifies the number of seconds a MAC Address will be
kept in the forwarding database after having a packet received
from this MAC Address.
Added in version 232.
Priority=
The priority of the bridge. An integer between 0 and 65535. A
lower value means higher priority. The bridge having the
lowest priority will be elected as root bridge.
Added in version 232.
GroupForwardMask=
A 16-bit bitmask represented as an integer which allows
forwarding of link local frames with 802.1D reserved addresses
(01:80:C2:00:00:0X). A logical AND is performed between the
specified bitmask and the exponentiation of 2^X, the lower
nibble of the last octet of the MAC address. For example, a
value of 8 would allow forwarding of frames addressed to
01:80:C2:00:00:03 (802.1X PAE).
Added in version 235.
DefaultPVID=
This specifies the default port VLAN ID of a newly attached
bridge port. Set this to an integer in the range 1...4094 or
"none" to disable the PVID.
Added in version 232.
MulticastQuerier=
Takes a boolean. This setting controls the
IFLA_BR_MCAST_QUERIER option in the kernel. If enabled, the
kernel will send general ICMP queries from a zero source
address. This feature should allow faster convergence on
startup, but it causes some multicast-aware switches to
misbehave and disrupt forwarding of multicast packets. When
unset, the kernel's default will be used.
Added in version 230.
MulticastSnooping=
Takes a boolean. This setting controls the
IFLA_BR_MCAST_SNOOPING option in the kernel. If enabled, IGMP
snooping monitors the Internet Group Management Protocol
(IGMP) traffic between hosts and multicast routers. When
unset, the kernel's default will be used.
Added in version 230.
VLANFiltering=
Takes a boolean. This setting controls the
IFLA_BR_VLAN_FILTERING option in the kernel. If enabled, the
bridge will be started in VLAN-filtering mode. When unset, the
kernel's default will be used.
Added in version 231.
VLANProtocol=
Allows setting the protocol used for VLAN filtering. Takes
802.1q or, 802.1ad, and defaults to unset and kernel's default
is used.
Added in version 246.
STP=
Takes a boolean. This enables the bridge's Spanning Tree
Protocol (STP). When unset, the kernel's default will be used.
Added in version 232.
MulticastIGMPVersion=
Allows changing bridge's multicast Internet Group Management
Protocol (IGMP) version. Takes an integer 2 or 3. When unset,
the kernel's default will be used.
Added in version 243.
FDBMaxLearned=
Specifies the maximum number of learned Ethernet addresses for
the bridge. When the limit is reached, no more addresses are
learned. When unset, the kernel's default will be used. 0
disables the limit.
Added in version 257.
LinkLocalLearning=
Takes a boolean. This enables learning source addresses from
link local frames. When unset, the kernel's default will be
used.
Added in version 258.
The [VLAN] section only applies for netdevs of kind "vlan", and
accepts the following key:
Id=
The VLAN ID to use. An integer in the range 0...4094. This
setting is compulsory.
Added in version 211.
Protocol=
Allows setting the protocol used for the VLAN interface. Takes
"802.1q" or, "802.1ad", and defaults to unset and kernel's
default is used.
Added in version 248.
GVRP=
Takes a boolean. The Generic VLAN Registration Protocol (GVRP)
is a protocol that allows automatic learning of VLANs on a
network. When unset, the kernel's default will be used.
Added in version 234.
MVRP=
Takes a boolean. Multiple VLAN Registration Protocol (MVRP)
formerly known as GARP VLAN Registration Protocol (GVRP) is a
standards-based Layer 2 network protocol, for automatic
configuration of VLAN information on switches. It was defined
in the 802.1ak amendment to 802.1Q-2005. When unset, the
kernel's default will be used.
Added in version 234.
LooseBinding=
Takes a boolean. The VLAN loose binding mode, in which only
the operational state is passed from the parent to the
associated VLANs, but the VLAN device state is not changed.
When unset, the kernel's default will be used.
Added in version 234.
ReorderHeader=
Takes a boolean. When enabled, the VLAN reorder header is used
and VLAN interfaces behave like physical interfaces. When
unset, the kernel's default will be used.
Added in version 234.
EgressQOSMaps=, IngressQOSMaps=
Defines a mapping of Linux internal packet priority
(SO_PRIORITY) to VLAN header PCP field for outgoing and
incoming frames, respectively. Takes a whitespace-separated
list of integer pairs, where each integer must be in the range
1...4294967294, in the format "from"-"to", e.g., "21-7 45-5".
Note that "from" must be greater than or equal to "to". When
unset, the kernel's default will be used.
Added in version 248.
The [MACVLAN] section only applies for netdevs of kind "macvlan",
and accepts the following key:
Mode=
The MACVLAN mode to use. The supported options are "private",
"vepa", "bridge", "passthru", and "source".
Added in version 211.
SourceMACAddress=
A whitespace-separated list of remote hardware addresses
allowed on the MACVLAN. This option only has an effect in
source mode. Use full colon-, hyphen- or dot-delimited
hexadecimal. This option may appear more than once, in which
case the lists are merged. If the empty string is assigned to
this option, the list of hardware addresses defined prior to
this is reset. Defaults to unset.
Added in version 246.
BroadcastMulticastQueueLength=
Specifies the length of the receive queue for
broadcast/multicast packets. An unsigned integer in the range
0...4294967294. Defaults to unset.
Added in version 248.
BroadcastQueueThreshold=
Controls the threshold for broadcast queueing of the macvlan
device. Takes the special value "no", or an integer in the
range 0...2147483647. When "no" is specified, the broadcast
queueing is disabled altogether. When an integer is specified,
a multicast address will be queued as broadcast if the number
of devices using the macvlan is greater than the given value.
Defaults to unset, and the kernel default will be used.
Added in version 256.
The [MACVTAP] section applies for netdevs of kind "macvtap" and
accepts the same keys as [MACVLAN].
The [IPVLAN] section only applies for netdevs of kind "ipvlan",
and accepts the following key:
Mode=
The IPVLAN mode to use. The supported options are "L2","L3"
and "L3S".
Added in version 219.
Flags=
The IPVLAN flags to use. The supported options are
"bridge","private" and "vepa".
Added in version 237.
The [IPVTAP] section only applies for netdevs of kind "ipvtap" and
accepts the same keys as [IPVLAN].
The [VXLAN] section only applies for netdevs of kind "vxlan", and
accepts the following keys:
VNI=
The VXLAN Network Identifier (or VXLAN Segment ID). Takes a
number in the range 1...16777215. Ignored if External= is set
to true.
Added in version 243.
Remote=
Configures destination IP address.
Added in version 233.
Local=
Configures local IP address. It must be an address on the
underlying interface of the VXLAN interface, or one of the
special values "ipv4_link_local", "ipv6_link_local", "dhcp4",
"dhcp6", and "slaac". If one of the special values is
specified, an address which matches the corresponding type on
the underlying interface will be used. Defaults to unset.
Added in version 233.
Group=
Configures VXLAN multicast group IP address. All members of a
VXLAN must use the same multicast group address.
Added in version 243.
TOS=
The Type Of Service byte value for a vxlan interface.
Added in version 215.
TTL=
A fixed Time To Live N on Virtual eXtensible Local Area
Network packets. Takes "inherit" or a number in the range
0...255. 0 is a special value meaning inherit the inner
protocol's TTL value. "inherit" means that it will inherit
the outer protocol's TTL value.
Added in version 215.
MacLearning=
Takes a boolean. When true, enables dynamic MAC learning to
discover remote MAC addresses.
Added in version 215.
FDBAgeingSec=
The lifetime of Forwarding Database entry learnt by the
kernel, in seconds.
Added in version 218.
MaximumFDBEntries=
Configures maximum number of FDB entries.
Added in version 228.
ReduceARPProxy=
Takes a boolean. When true, bridge-connected VXLAN tunnel
endpoint answers ARP requests from the local bridge on behalf
of remote Distributed Overlay Virtual Ethernet (DOVE)[7]
clients. Defaults to false.
Added in version 233.
L2MissNotification=
Takes a boolean. When true, enables netlink LLADDR miss
notifications.
Added in version 218.
L3MissNotification=
Takes a boolean. When true, enables netlink IP address miss
notifications.
Added in version 218.
RouteShortCircuit=
Takes a boolean. When true, route short circuiting is turned
on.
Added in version 218.
UDPChecksum=
Takes a boolean. When true, transmitting UDP checksums when
doing VXLAN/IPv4 is turned on.
Added in version 220.
UDP6ZeroChecksumTx=
Takes a boolean. When true, sending zero checksums in
VXLAN/IPv6 is turned on.
Added in version 220.
UDP6ZeroChecksumRx=
Takes a boolean. When true, receiving zero checksums in
VXLAN/IPv6 is turned on.
Added in version 220.
RemoteChecksumTx=
Takes a boolean. When true, remote transmit checksum offload
of VXLAN is turned on.
Added in version 232.
RemoteChecksumRx=
Takes a boolean. When true, remote receive checksum offload in
VXLAN is turned on.
Added in version 232.
GroupPolicyExtension=
Takes a boolean. When true, it enables Group Policy VXLAN
extension security label mechanism across network peers based
on VXLAN. For details about the Group Policy VXLAN, see the
VXLAN Group Policy[8] document. Defaults to false.
Added in version 224.
GenericProtocolExtension=
Takes a boolean. When true, Generic Protocol Extension extends
the existing VXLAN protocol to provide protocol typing, OAM,
and versioning capabilities. For details about the VXLAN GPE
Header, see the Generic Protocol Extension for VXLAN[9]
document. If destination port is not specified and Generic
Protocol Extension is set, the default port of 4790 is used.
Defaults to false.
Added in version 243.
DestinationPort=
Configures the default destination UDP port. If the
destination port is not specified, the Linux kernel default
will be used. Set to 4789 to get the IANA assigned value.
Added in version 229.
PortRange=
Configures the source port range for the VXLAN. The kernel
assigns the source UDP port based on the flow to help the
receiver to do load balancing. When this option is not set,
the normal range of local UDP ports is used.
Added in version 229.
FlowLabel=
Specifies the flow label to use in outgoing packets. The valid
range is 0-1048575.
Added in version 234.
IPDoNotFragment=
Allows setting the IPv4 Do not Fragment (DF) bit in outgoing
packets, or to inherit its value from the IPv4 inner header.
Takes a boolean value, or "inherit". Set to "inherit" if the
encapsulated protocol is IPv6. When unset, the kernel's
default will be used.
Added in version 243.
Independent=
Takes a boolean. When true, the vxlan interface is created
without any underlying network interface. Defaults to false,
which means that a .network file that requests this VXLAN
interface using VXLAN= is required for the VXLAN to be
created.
Added in version 247.
External=
Takes a boolean. When true, the vxlan interface is externally
controlled, for example by an EVPN control plane. Defaults to
false.
Added in version 258.
VNIFilter=
Takes a boolean. When true, the interface is capable of
filtering VNI filtering. Ignored if External= is set to false.
Defaults to false.
Added in version 258.
The [GENEVE] section only applies for netdevs of kind "geneve",
and accepts the following keys:
Id=
Specifies the Virtual Network Identifier (VNI) to use, a
number between 0 and 16777215. This field is mandatory.
Added in version 234.
Remote=
Specifies the unicast destination IP address to use in
outgoing packets.
Added in version 234.
TOS=
Specifies the TOS value to use in outgoing packets. Takes a
number between 1 and 255.
Added in version 234.
TTL=
Accepts the same values as in the [VXLAN] section, except that
when unset or set to 0, the kernel's default will be used,
meaning that packet TTL will be set from
/proc/sys/net/ipv4/ip_default_ttl.
Added in version 234.
UDPChecksum=
Takes a boolean. When true, specifies that UDP checksum is
calculated for transmitted packets over IPv4.
Added in version 234.
UDP6ZeroChecksumTx=
Takes a boolean. When true, skip UDP checksum calculation for
transmitted packets over IPv6.
Added in version 234.
UDP6ZeroChecksumRx=
Takes a boolean. When true, allows incoming UDP packets over
IPv6 with zero checksum field.
Added in version 234.
DestinationPort=
Specifies destination port. Defaults to 6081. If not set or
assigned the empty string, the default port of 6081 is used.
Added in version 234.
FlowLabel=
Specifies the flow label to use in outgoing packets.
Added in version 234.
IPDoNotFragment=
Accepts the same key as in [VXLAN] section.
Added in version 243.
InheritInnerProtocol=
Takes a boolean. When true, inner Layer 3 protocol is set as
Protocol Type in the GENEVE header instead of Ethernet.
Defaults to false.
Added in version 254.
The [HSR] section only applies for netdevs of kind "hsr", and
accepts the following keys:
Ports=
Specifies the underlying interfaces. This field is mandatory
and must contain exactly two interface names separated by
space. This option can be specified multiples times, hence the
two cases below have the same result:
Ports=eth1 eth2
Ports=eth1
Ports=eth2
All the previous assignments are cleared when an empty string
is specified.
Added in version 258.
Protocol=
Specifies the protocol used by the interface. Takes one of
"hsr" or "prp". Defaults to "hsr".
Both protocols work by sending two copies of every outgoing
frame, one for each of the two ports. The destination node
receives the two frames and and keeps only the first one. If a
link fails, only one of the two frames is received. HSR uses a
ring topology where the two outgoing frames are sent in
opposite directions in the ring. PRP doesn't need a specific
topology, but it requires two completely redundant networks
attached to the two ports.
Added in version 258.
Supervision=
Specifies the last byte of the destination MAC address of
supervision frames. Takes a number between 0 and 255. Defaults
to 0. Supervision frames are used by the HSR and the PRP
protocols to monitor the integrity of the network and the
presence of nodes. The first 5 bytes of the destination MAC
are always 01:15:4E:00:01 while the last byte is configurable.
Added in version 258.
The [BareUDP] section only applies for netdevs of kind "bareudp",
and accepts the following keys:
DestinationPort=
Specifies the destination UDP port (in range 1...65535). This
is mandatory.
Added in version 247.
EtherType=
Specifies the L3 protocol. Takes one of "ipv4", "ipv6",
"mpls-uc" or "mpls-mc". This is mandatory.
Added in version 247.
MinSourcePort=
Specifies the lowest value of the UDP tunnel source port (in
range 1...65535). Defaults to unset.
Added in version 257.
The [L2TP] section only applies for netdevs of kind "l2tp", and
accepts the following keys:
TunnelId=
Specifies the tunnel identifier. Takes a number in the range
1...4294967295. The value used must match the "PeerTunnelId="
value being used at the peer. This setting is compulsory.
Added in version 242.
PeerTunnelId=
Specifies the peer tunnel id. Takes a number in the range
1...4294967295. The value used must match the "TunnelId="
value being used at the peer. This setting is compulsory.
Added in version 242.
Remote=
Specifies the IP address of the remote peer. This setting is
compulsory.
Added in version 242.
Local=
Specifies the IP address of a local interface. Takes an IP
address, or the special values "auto", "static", or "dynamic".
Optionally a name of a local interface can be specified after
"@", e.g. "192.168.0.1@eth0" or "auto@eth0". When an address
is specified, then a local or specified interface must have
the address, and the remote address must be accessible through
the local address. If "auto", then one of the addresses on a
local or specified interface which is accessible to the remote
address will be used. Similarly, if "static" or "dynamic" is
set, then one of the static or dynamic addresses will be used.
Defaults to "auto".
Added in version 242.
EncapsulationType=
Specifies the encapsulation type of the tunnel. Takes one of
"udp" or "ip".
Added in version 242.
UDPSourcePort=
Specifies the UDP source port to be used for the tunnel. When
UDP encapsulation is selected it is mandatory. Ignored when IP
encapsulation is selected.
Added in version 242.
UDPDestinationPort=
Specifies destination port. When UDP encapsulation is selected
it is mandatory. Ignored when IP encapsulation is selected.
Added in version 245.
UDPChecksum=
Takes a boolean. When true, specifies that UDP checksum is
calculated for transmitted packets over IPv4.
Added in version 242.
UDP6ChecksumTx=
Takes a boolean. When true, skip UDP checksum calculation for
transmitted packets over IPv6.
Added in version 242.
UDP6ChecksumRx=
Takes a boolean. When true, allows incoming UDP packets over
IPv6 with zero checksum field.
Added in version 242.
The [L2TPSession] section only applies for netdevs of kind "l2tp",
and accepts the following keys:
Name=
Specifies the name of the session. This setting is compulsory.
Added in version 242.
SessionId=
Specifies the session identifier. Takes a number in the range
1...4294967295. The value used must match the "SessionId="
value being used at the peer. This setting is compulsory.
Added in version 242.
PeerSessionId=
Specifies the peer session identifier. Takes a number in the
range 1...4294967295. The value used must match the
"PeerSessionId=" value being used at the peer. This setting is
compulsory.
Added in version 242.
Layer2SpecificHeader=
Specifies layer2specific header type of the session. One of
"none" or "default". Defaults to "default".
Added in version 242.
The [MACsec] section only applies for network devices of kind
"macsec", and accepts the following keys:
Port=
Specifies the port to be used for the MACsec transmit channel.
The port is used to make secure channel identifier (SCI).
Takes a value between 1 and 65535. Defaults to unset.
Added in version 243.
Encrypt=
Takes a boolean. When true, enable encryption. Defaults to
unset.
Added in version 243.
The [MACsecReceiveChannel] section only applies for network
devices of kind "macsec", and accepts the following keys:
Port=
Specifies the port to be used for the MACsec receive channel.
The port is used to make secure channel identifier (SCI).
Takes a value between 1 and 65535. This option is compulsory,
and is not set by default.
Added in version 243.
MACAddress=
Specifies the MAC address to be used for the MACsec receive
channel. The MAC address used to make secure channel
identifier (SCI). This setting is compulsory, and is not set
by default.
Added in version 243.
The [MACsecTransmitAssociation] section only applies for network
devices of kind "macsec", and accepts the following keys:
PacketNumber=
Specifies the packet number to be used for replay protection
and the construction of the initialization vector (along with
the secure channel identifier [SCI]). Takes a value between
1-4,294,967,295. Defaults to unset.
Added in version 243.
KeyId=
Specifies the identification for the key. Takes a number
between 0-255. This option is compulsory, and is not set by
default.
Added in version 243.
Key=
Specifies the encryption key used in the transmission channel.
The same key must be configured on the peer’s matching receive
channel. This setting is compulsory, and is not set by
default. Takes a 128-bit key encoded in a hexadecimal string,
for example "dffafc8d7b9a43d5b9a3dfbbf6a30c16".
Added in version 243.
KeyFile=
Takes an absolute path to a file which contains a 128-bit key
encoded in a hexadecimal string, which will be used in the
transmission channel. When this option is specified, Key= is
ignored. Note that the file must be readable by the user
"systemd-network", so it should be, e.g., owned by
"root:systemd-network" with a "0640" file mode. If the path
refers to an AF_UNIX stream socket in the file system a
connection is made to it and the key read from it.
Added in version 243.
Activate=
Takes a boolean. If enabled, then the security association is
activated. Defaults to unset.
Added in version 243.
UseForEncoding=
Takes a boolean. If enabled, then the security association is
used for encoding. Only one [MACsecTransmitAssociation]
section can enable this option. When enabled, Activate=yes is
implied. Defaults to unset.
Added in version 243.
The [MACsecReceiveAssociation] section only applies for network
devices of kind "macsec", and accepts the following keys:
Port=
Accepts the same key as in [MACsecReceiveChannel] section.
Added in version 243.
MACAddress=
Accepts the same key as in [MACsecReceiveChannel] section.
Added in version 243.
PacketNumber=
Accepts the same key as in [MACsecTransmitAssociation]
section.
Added in version 243.
KeyId=
Accepts the same key as in [MACsecTransmitAssociation]
section.
Added in version 243.
Key=
Accepts the same key as in [MACsecTransmitAssociation]
section.
Added in version 243.
KeyFile=
Accepts the same key as in [MACsecTransmitAssociation]
section.
Added in version 243.
Activate=
Accepts the same key as in [MACsecTransmitAssociation]
section.
Added in version 243.
The [Tunnel] section only applies for netdevs of kind "ipip",
"sit", "gre", "gretap", "ip6gre", "ip6gretap", "vti", "vti6",
"ip6tnl", and "erspan" and accepts the following keys:
External=
Takes a boolean value. When true, then the tunnel is
externally controlled, which is also known as collect metadata
mode, and most settings below like Local= or Remote= are
ignored. This implies Independent=. Defaults to false.
Added in version 251.
Local=
A static local address for tunneled packets. It must be an
address on another interface of this host, or one of the
special values "any", "ipv4_link_local", "ipv6_link_local",
"dhcp4", "dhcp6", "dhcp_pd", and "slaac". If one of the
special values except for "any" is specified, an address which
matches the corresponding type on the underlying interface
will be used. Defaults to "any".
Added in version 215.
Remote=
The remote endpoint of the tunnel. Takes an IP address or the
special value "any".
Added in version 215.
TOS=
The Type Of Service byte value for a tunnel interface. For
details about the TOS, see the Type of Service in the Internet
Protocol Suite[10] document.
Added in version 215.
TTL=
A fixed Time To Live 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 0
(inherit). The default value for IPv6 tunnels is 64.
Added in version 215.
DiscoverPathMTU=
Takes a boolean. When true, enables Path MTU Discovery on the
tunnel. When IgnoreDontFragment= is enabled, defaults to
false. Otherwise, defaults to true.
Added in version 215.
IgnoreDontFragment=
Takes a boolean. When true, enables IPv4 Don't Fragment (DF)
suppression on the tunnel. Defaults to false. Note that if
IgnoreDontFragment= is set to true, DiscoverPathMTU= cannot be
set to true. Only applicable to GRE, GRETAP, and ERSPAN
tunnels.
Added in version 254.
IPv6FlowLabel=
Configures the 20-bit flow label (see RFC 6437[11]) field in
the IPv6 header (see RFC 2460[12]), which is used by a node to
label packets of a flow. It is only used for IPv6 tunnels. A
flow label of zero is used to indicate packets that have not
been labeled. It can be configured to a value in the range
0...0xFFFFF, or be set to "inherit", in which case the
original flowlabel is used.
Added in version 223.
CopyDSCP=
Takes a boolean. When true, the Differentiated Service Code
Point (DSCP) field will be copied to the inner header from
outer header during the decapsulation of an IPv6 tunnel
packet. DSCP is a field in an IP packet that enables different
levels of service to be assigned to network traffic. Defaults
to "no".
Added in version 223.
EncapsulationLimit=
The Tunnel Encapsulation Limit option specifies how many
additional levels of encapsulation are permitted to be
prepended to the packet. For example, a Tunnel Encapsulation
Limit option containing a limit value of zero means that a
packet carrying that option may not enter another tunnel
before exiting the current tunnel. (see RFC 2473[13]). The
valid range is 0...255 and "none". Defaults to 4.
Added in version 226.
Key=
The Key= parameter specifies the same key to use in both
directions (InputKey= and OutputKey=). The Key= is either a
number or an IPv4 address-like dotted quad. It is used as
mark-configured SAD/SPD entry as part of the lookup key (both
in data and control path) in IP XFRM (framework used to
implement IPsec protocol). See ip-xfrm — transform
configuration[14] for details. It is only used for VTI/VTI6,
GRE, GRETAP, and ERSPAN tunnels.
Added in version 231.
InputKey=
The InputKey= parameter specifies the key to use for input.
The format is same as Key=. It is only used for VTI/VTI6, GRE,
GRETAP, and ERSPAN tunnels.
Added in version 231.
OutputKey=
The OutputKey= parameter specifies the key to use for output.
The format is same as Key=. It is only used for VTI/VTI6, GRE,
GRETAP, and ERSPAN tunnels.
Added in version 231.
Mode=
Specifies the tunnel mode. Acceptable values depend on the
tunnel kind.
Table 2. Supported tunnel modes
┌──────────┬──────────┬────────────────────┐
│ Kind │ Mode │ Description │
├──────────┼──────────┼────────────────────┤
│ │ "ipip" │ IPv4 over IPv4 │
│ │ │ (default) │
│ "ipip" ├──────────┼────────────────────┤
│ │ "any" │ both IPv4 and IPv6 │
│ │ │ over IPv4 │
├──────────┼──────────┼────────────────────┤
│ │ "ipip" │ IPv4 over IPv4 │
│ ├──────────┼────────────────────┤
│ │ "ip6ip" │ IPv6 over IPv4 │
│ "sit" │ │ (default) │
│ ├──────────┼────────────────────┤
│ │ "any" │ both IPv4 and IPv6 │
│ │ │ over IPv4 │
├──────────┼──────────┼────────────────────┤
│ │ "ipip6" │ IPv4 over IPv6 │
│ ├──────────┼────────────────────┤
│ │ "ip6ip6" │ IPv6 over IPv6 │
│ "ip6tnl" ├──────────┼────────────────────┤
│ │ "any" │ both IPv4 and IPv6 │
│ │ │ over IPv6 │
│ │ │ (default) │
└──────────┴──────────┴────────────────────┘
Added in version 219.
Independent=
Takes a boolean. When false (the default), the tunnel is
always created over some network device, and a .network file
that requests this tunnel using Tunnel= is required for the
tunnel to be created. When true, the tunnel is created
independently of any network as "tunnel@NONE".
Added in version 235.
AssignToLoopback=
Takes a boolean. If set to "yes", the loopback interface "lo"
is used as the underlying device of the tunnel interface.
Defaults to "no".
Added in version 243.
AllowLocalRemote=
Takes a boolean. When true allows tunnel traffic on ip6tnl
devices where the remote endpoint is a local host address.
When unset, the kernel's default will be used.
Added in version 237.
FooOverUDP=
Takes a boolean. Specifies whether FooOverUDP= tunnel is to be
configured. Defaults to false. This takes effects only for
IPIP, SIT, GRE, and GRETAP tunnels. For more detail
information see Foo over UDP[15]
Added in version 240.
FOUDestinationPort=
This setting specifies the UDP destination port for
encapsulation. This field is mandatory when FooOverUDP=yes,
and is not set by default.
Added in version 240.
FOUSourcePort=
This setting specifies the UDP source port for encapsulation.
Defaults to 0 — that is, the source port for packets is left
to the network stack to decide.
Added in version 240.
Encapsulation=
Accepts the same key as in the [FooOverUDP] section.
Added in version 240.
IPv6RapidDeploymentPrefix=
Reconfigure the tunnel for IPv6 Rapid Deployment[16], also
known as 6rd. The value is an ISP-specific IPv6 prefix with a
non-zero length. Only applicable to SIT tunnels.
Added in version 240.
ISATAP=
Takes a boolean. If set, configures the tunnel as Intra-Site
Automatic Tunnel Addressing Protocol (ISATAP) tunnel. Only
applicable to SIT tunnels. When unset, the kernel's default
will be used.
Added in version 240.
SerializeTunneledPackets=
Takes a boolean. If set to yes, then packets are serialized.
Only applies for GRE, GRETAP, and ERSPAN tunnels. When unset,
the kernel's default will be used.
Added in version 240.
ERSPANVersion=
Specifies the ERSPAN version number. Takes 0 for version 0
(a.k.a. type I), 1 for version 1 (a.k.a. type II), or 2 for
version 2 (a.k.a. type III). Defaults to 1.
Added in version 252.
ERSPANIndex=
Specifies the ERSPAN v1 index field for the interface. Takes
an integer in the range 0...1048575, which is associated with
the ERSPAN traffic's source port and direction. Only used when
ERSPANVersion=1. Defaults to 0.
Added in version 240.
ERSPANDirection=
Specifies the ERSPAN v2 mirrored traffic's direction. Takes
"ingress" or "egress". Only used when ERSPANVersion=2.
Defaults to "ingress".
Added in version 252.
ERSPANHardwareId=
Specifies a unique identifier of the ERSPAN v2 engine. Takes
an integer in the range 0...63. Only used when
ERSPANVersion=2. Defaults to 0.
Added in version 252.
The [FooOverUDP] section only applies for netdevs of kind "fou"
and accepts the following keys:
Encapsulation=
Specifies the encapsulation mechanism used to store networking
packets of various protocols inside the UDP packets. Supports
the following values: "FooOverUDP" provides the simplest
no-frills model of UDP encapsulation, it simply encapsulates
packets directly in the UDP payload.
"GenericUDPEncapsulation" is a generic and extensible
encapsulation, it allows encapsulation of packets for any IP
protocol and optional data as part of the encapsulation. For
more detailed information see Generic UDP Encapsulation[17].
Defaults to "FooOverUDP".
Added in version 240.
Port=
Specifies the port number where the encapsulated packets will
arrive. Those packets will be removed and manually fed back
into the network stack with the encapsulation removed to be
sent to the real destination. This option is mandatory.
Added in version 240.
PeerPort=
Specifies the peer port number. Defaults to unset. Note that
when peer port is set "Peer=" address is mandatory.
Added in version 243.
Protocol=
The Protocol= specifies the protocol number of the packets
arriving at the UDP port. When Encapsulation=FooOverUDP, this
field is mandatory and is not set by default. Takes an IP
protocol name such as "gre" or "ipip", or an integer within
the range 1...255. When Encapsulation=GenericUDPEncapsulation,
this must not be specified.
Added in version 240.
Peer=
Configures peer IP address. Note that when peer address is set
"PeerPort=" is mandatory.
Added in version 243.
Local=
Configures local IP address.
Added in version 243.
The [Peer] section only applies for netdevs of kind "veth" and
accepts the following keys:
Name=
The interface name used when creating the netdev. This setting
is compulsory.
Added in version 215.
MACAddress=
The peer MACAddress, if not set, it is generated in the same
way as the MAC address of the main interface.
Added in version 215.
The [VXCAN] section only applies for netdevs of kind "vxcan" and
accepts the following key:
Peer=
The peer interface name used when creating the netdev. This
setting is compulsory.
Added in version 236.
The [Tun] section only applies for netdevs of kind "tun", and
accepts the following keys:
MultiQueue=
Takes a boolean. Configures whether to use multiple file
descriptors (queues) to parallelize packets sending and
receiving. Defaults to "no".
Added in version 215.
PacketInfo=
Takes a boolean. Configures whether packets should be
prepended with four extra bytes (two flag bytes and two
protocol bytes). If disabled, it indicates that the packets
will be pure IP packets. Defaults to "no".
Added in version 215.
VNetHeader=
Takes a boolean. Configures IFF_VNET_HDR flag for a tun or tap
device. It allows sending and receiving larger Generic
Segmentation Offload (GSO) packets. This may increase
throughput significantly. Defaults to "no".
Added in version 223.
User=
User to grant access to the /dev/net/tun device. The specified
user must be a system user.
Added in version 215.
Group=
Group to grant access to the /dev/net/tun device. The
specified group must be a system group.
Added in version 215.
KeepCarrier=
Takes a boolean. If enabled, to make the interface maintain
its carrier status, the file descriptor of the interface is
kept open. This may be useful to keep the interface in running
state, for example while the backing process is temporarily
shutdown. Defaults to "no".
Added in version 252.
The [Tap] section only applies for netdevs of kind "tap", and
accepts the same keys as the [Tun] section.
The [WireGuard] section accepts the following keys:
PrivateKey=
The Base64 encoded private key for the interface. It can be
generated using the wg genkey command (see wg(8)). Specially,
if the specified key is prefixed with "@", it is interpreted
as the name of the credential from which the actual key shall
be read. systemd-networkd.service(8) automatically imports
credentials matching "network.wireguard.*". For more details
on credentials, refer to systemd.exec(5). A private key is
mandatory to use WireGuard. If not set, the credential
"network.wireguard.private.netdev" is used if exists. I.e. for
50-foobar.netdev, "network.wireguard.private.50-foobar" is
tried.
Note that because this information is secret, it is strongly
recommended to use an (encrypted) credential. Alternatively,
you may want to set the permissions of the .netdev file to be
owned by "root:systemd-network" with a "0640" file mode.
Added in version 237.
PrivateKeyFile=
Takes an absolute path to a file which contains the Base64
encoded private key for the interface. When this option is
specified, then PrivateKey= is ignored. Note that the file
must be readable by the user "systemd-network", so it should
be, e.g., owned by "root:systemd-network" with a "0640" file
mode. If the path refers to an AF_UNIX stream socket in the
file system a connection is made to it and the key read from
it.
Added in version 242.
ListenPort=
Sets UDP port for listening. Takes either value between 1 and
65535 or "auto". If "auto" is specified, the port is
automatically generated based on interface name. Defaults to
"auto".
Added in version 237.
FirewallMark=
Sets a firewall mark on outgoing WireGuard packets from this
interface. Takes a number between 1 and 4294967295.
Added in version 243.
RouteTable=
The table identifier for the routes to the addresses specified
in the AllowedIPs=. Takes a negative boolean value, one of the
predefined names "default", "main", and "local", names defined
in RouteTable= in networkd.conf(5), or a number in the range
1...4294967295. When "off" the routes to the addresses
specified in the AllowedIPs= setting will not be configured.
Defaults to false. This setting will be ignored when the same
setting is specified in the [WireGuardPeer] section.
Added in version 250.
RouteMetric=
The priority of the routes to the addresses specified in the
AllowedIPs=. Takes an integer in the range 0...4294967295.
Defaults to 0 for IPv4 addresses, and 1024 for IPv6 addresses.
This setting will be ignored when the same setting is
specified in the [WireGuardPeer] section.
Added in version 250.
The [WireGuardPeer] section accepts the following keys:
PublicKey=
Sets a Base64 encoded public key calculated by wg pubkey (see
wg(8)) from a private key, and usually transmitted out of band
to the author of the configuration file. This option honors
the "@" prefix in the same way as the PrivateKey= setting of
the [WireGuard] section. This option is mandatory for this
section.
Added in version 237.
PublicKeyFile=
Takes an absolute path to a file which contains the Base64
encoded public key for the peer. When this option is
specified, then PublicKey= will be ignored. Note that the file
must be readable by the user "systemd-network", so it should
be, e.g., owned by "root:systemd-network" with a "0640" file
mode. If the path refers to an AF_UNIX stream socket in the
file system a connection is made to it and the key read from
it.
Added in version 257.
PresharedKey=
Optional preshared key for the interface. It can be generated
by the wg genpsk command. This option adds an additional layer
of symmetric-key cryptography to be mixed into the already
existing public-key cryptography, for post-quantum resistance.
This option honors the "@" prefix in the same way as the
PrivateKey= setting of the [WireGuard] section.
Note that because this information is secret, it is strongly
recommended to use an (encrypted) credential. Alternatively,
you may want to set the permissions of the .netdev file to be
owned by "root:systemd-network" with a "0640" file mode.
Added in version 237.
PresharedKeyFile=
Takes an absolute path to a file which contains the Base64
encoded preshared key for the peer. When this option is
specified, then PresharedKey= is ignored. Note that the file
must be readable by the user "systemd-network", so it should
be, e.g., owned by "root:systemd-network" with a "0640" file
mode. If the path refers to an AF_UNIX stream socket in the
file system a connection is made to it and the key read from
it.
Added in version 242.
AllowedIPs=
Sets a comma-separated list of IP (v4 or v6) addresses with
CIDR masks from which this peer is allowed to send incoming
traffic and to which outgoing traffic for this peer is
directed. This setting can be specified multiple times. If an
empty string is assigned, then the all previous assignments
are cleared.
The catch-all 0.0.0.0/0 may be specified for matching all IPv4
addresses, and ::/0 may be specified for matching all IPv6
addresses.
Note that this only affects routing inside the network
interface itself, i.e. the packets that pass through the
tunnel itself. To cause packets to be sent via the tunnel in
the first place, an appropriate route needs to be added as
well — either in the "[Routes]" section on the ".network"
matching the wireguard interface, or externally to
systemd-networkd.
Added in version 237.
Endpoint=
Sets an endpoint IP address or hostname, followed by a colon,
and then a port number. IPv6 address must be in the square
brackets. For example, "111.222.333.444:51820" for IPv4 and
"[1111:2222::3333]:51820" for IPv6 address. This endpoint will
be updated automatically once to the most recent source IP
address and port of correctly authenticated packets from the
peer at configuration time.
This option honors the "@" prefix in the same way as the
PrivateKey= setting of the [WireGuard] section.
Added in version 237.
PersistentKeepalive=
Sets a seconds interval, between 1 and 65535 inclusive, of how
often to send an authenticated empty packet to the peer for
the purpose of keeping a stateful firewall or NAT mapping
valid persistently. For example, if the interface very rarely
sends traffic, but it might at anytime receive traffic from a
peer, and it is behind NAT, the interface might benefit from
having a persistent keepalive interval of 25 seconds. If set
to 0 or "off", this option is disabled. By default or when
unspecified, this option is off. Most users will not need
this.
Added in version 237.
RouteTable=
The table identifier for the routes to the addresses specified
in the AllowedIPs=. Takes a negative boolean value, one of the
predefined names "default", "main", and "local", names defined
in RouteTable= in networkd.conf(5), or a number in the range
1...4294967295. Defaults to unset, and the value specified in
the same setting in the [WireGuard] section will be used.
Added in version 250.
RouteMetric=
The priority of the routes to the addresses specified in the
AllowedIPs=. Takes an integer in the range 0...4294967295.
Defaults to unset, and the value specified in the same setting
in the [WireGuard] section will be used.
Added in version 250.
The [Bond] section accepts the following key:
Mode=
Specifies one of the bonding policies. The default is
"balance-rr" (round robin). Possible values are "balance-rr",
"active-backup", "balance-xor", "broadcast", "802.3ad",
"balance-tlb", and "balance-alb".
Added in version 216.
TransmitHashPolicy=
Selects the transmit hash policy to use for slave selection in
balance-xor, 802.3ad, and tlb modes. Possible values are
"layer2", "layer3+4", "layer2+3", "encap2+3", and "encap3+4".
Added in version 216.
LACPTransmitRate=
Specifies the rate with which link partner transmits Link
Aggregation Control Protocol Data Unit packets in 802.3ad
mode. Possible values are "slow", which requests partner to
transmit LACPDUs every 30 seconds, and "fast", which requests
partner to transmit LACPDUs every second. The default value is
"slow".
Added in version 216.
MIIMonitorSec=
Specifies the frequency that Media Independent Interface link
monitoring will occur. A value of zero disables MII link
monitoring. This value is rounded down to the nearest
millisecond. The default value is 0.
Added in version 216.
PeerNotifyDelaySec=
Specifies the number of seconds the delay between each peer
notification (gratuitous ARP and unsolicited IPv6 Neighbor
Advertisement) when they are issued after a failover event.
This delay should be a multiple of the MII link monitor
interval (miimon). The valid range is 0...300s. The default
value is 0, which means to match the value of the
MIIMonitorSec=.
Added in version 256.
UpDelaySec=
Specifies the delay before a link is enabled after a link up
status has been detected. This value is rounded down to a
multiple of MIIMonitorSec=. The default value is 0.
Added in version 216.
DownDelaySec=
Specifies the delay before a link is disabled after a link
down status has been detected. This value is rounded down to a
multiple of MIIMonitorSec=. The default value is 0.
Added in version 216.
LearnPacketIntervalSec=
Specifies the number of seconds between instances where the
bonding driver sends learning packets to each slave peer
switch. The valid range is 1...0x7fffffff; the default value
is 1. This option has an effect only for the balance-tlb and
balance-alb modes.
Added in version 220.
AdSelect=
Specifies the 802.3ad aggregation selection logic to use.
Possible values are "stable", "bandwidth" and "count".
Added in version 220.
AdActorSystemPriority=
Specifies the 802.3ad actor system priority. Takes a number in
the range 1...65535.
Added in version 240.
AdUserPortKey=
Specifies the 802.3ad user defined portion of the port key.
Takes a number in the range 0...1023.
Added in version 240.
AdActorSystem=
Specifies the 802.3ad system MAC address. This cannot be a
null or multicast address.
Added in version 240.
FailOverMACPolicy=
Specifies whether the active-backup mode should set all slaves
to the same MAC address at the time of enslavement or, when
enabled, to perform special handling of the bond's MAC address
in accordance with the selected policy. The default policy is
none. Possible values are "none", "active" and "follow".
Added in version 220.
ARPValidate=
Specifies whether or not ARP probes and replies should be
validated in any mode that supports ARP monitoring, or whether
non-ARP traffic should be filtered (disregarded) for link
monitoring purposes. Possible values are "none", "active",
"backup" and "all".
Added in version 220.
ARPIntervalSec=
Specifies the ARP link monitoring frequency. A value of 0
disables ARP monitoring. The default value is 0, and the
default unit seconds.
Added in version 220.
ARPIPTargets=
Specifies the IP addresses to use as ARP monitoring peers when
ARPIntervalSec= is greater than 0. These are the targets of
the ARP request sent to determine the health of the link to
the targets. Specify these values in IPv4 dotted decimal
format. At least one IP address must be given for ARP
monitoring to function. The maximum number of targets that can
be specified is 16. The default value is no IP addresses.
Added in version 220.
ARPAllTargets=
Specifies the quantity of ARPIPTargets= that must be reachable
in order for the ARP monitor to consider a slave as being up.
This option affects only active-backup mode for slaves with
ARPValidate enabled. Possible values are "any" and "all".
Added in version 220.
PrimaryReselectPolicy=
Specifies the reselection policy for the primary slave. This
affects how the primary slave is chosen to become the active
slave when failure of the active slave or recovery of the
primary slave occurs. This option is designed to prevent
flip-flopping between the primary slave and other slaves.
Possible values are "always", "better" and "failure".
Added in version 220.
ResendIGMP=
Specifies the number of IGMP membership reports to be issued
after a failover event. One membership report is issued
immediately after the failover, subsequent packets are sent in
each 200ms interval. The valid range is 0...255. Defaults to
1. A value of 0 prevents the IGMP membership report from being
issued in response to the failover event.
Added in version 220.
PacketsPerSlave=
Specify the number of packets to transmit through a slave
before moving to the next one. When set to 0, then a slave is
chosen at random. The valid range is 0...65535. Defaults to 1.
This option only has effect when in balance-rr mode.
Added in version 220.
GratuitousARP=
Specify the number of peer notifications (gratuitous ARPs and
unsolicited IPv6 Neighbor Advertisements) to be issued after a
failover event. As soon as the link is up on the new slave, a
peer notification is sent on the bonding device and each VLAN
sub-device. This is repeated at each link monitor interval
(ARPIntervalSec or MIIMonitorSec, whichever is active) if the
number is greater than 1. The valid range is 0...255. The
default value is 1. These options affect only the
active-backup mode.
Added in version 220.
AllSlavesActive=
Takes a boolean. Specifies that duplicate frames (received on
inactive ports) should be dropped when false, or delivered
when true. Normally, bonding will drop duplicate frames
(received on inactive ports), which is desirable for most
users. But there are some cases where it is nice to allow
duplicate frames to be delivered. The default value is false
(drop duplicate frames received on inactive ports).
Added in version 220.
DynamicTransmitLoadBalancing=
Takes a boolean. Specifies if dynamic shuffling of flows is
enabled. Applies only for balance-tlb mode. Defaults to unset.
Added in version 240.
MinLinks=
Specifies the minimum number of links that must be active
before asserting carrier. The default value is 0.
Added in version 220.
ARPMissedMax=
Specify the maximum number of arp interval monitor cycle for
missed ARP replies. If this number is exceeded, link is
reported as down. Defaults to unset.
Added in version 256.
For more detail information see Linux Ethernet Bonding Driver
HOWTO[1]
The [Xfrm] section accepts the following keys:
InterfaceId=
Sets the ID/key of the xfrm interface which needs to be
associated with a SA/policy. Can be decimal or hexadecimal,
valid range is 1-0xffffffff. This is mandatory.
Added in version 243.
Independent=
Takes a boolean. If false (the default), the xfrm interface
must have an underlying device which can be used for hardware
offloading.
Added in version 243.
For more detail information see Virtual XFRM Interfaces[18].
The [VRF] section only applies for netdevs of kind "vrf" and
accepts the following key:
Table=
The numeric routing table identifier. This setting is
compulsory.
Added in version 243.
The [BatmanAdvanced] section only applies for netdevs of kind
"batadv" and accepts the following keys:
GatewayMode=
Takes one of "off", "server", or "client". A batman-adv node
can either run in server mode (sharing its internet connection
with the mesh) or in client mode (searching for the most
suitable internet connection in the mesh) or having the
gateway support turned off entirely (which is the default
setting).
Added in version 248.
Aggregation=
Takes a boolean value. Enables or disables aggregation of
originator messages. Defaults to true.
Added in version 248.
BridgeLoopAvoidance=
Takes a boolean value. Enables or disables avoidance of loops
on bridges. Defaults to true.
Added in version 248.
DistributedArpTable=
Takes a boolean value. Enables or disables the distributed ARP
table. Defaults to true.
Added in version 248.
Fragmentation=
Takes a boolean value. Enables or disables fragmentation.
Defaults to true.
Added in version 248.
HopPenalty=
The hop penalty setting allows one to modify batctl(8)
preference for multihop routes vs. short routes. This integer
value is applied to the TQ (Transmit Quality) of each
forwarded OGM (Originator Message), thereby propagating the
cost of an extra hop (the packet has to be received and
retransmitted which costs airtime). A higher hop penalty will
make it more unlikely that other nodes will choose this node
as intermediate hop towards any given destination. The default
hop penalty of '15' is a reasonable value for most setups and
probably does not need to be changed. However, mobile nodes
could choose a value of 255 (maximum value) to avoid being
chosen as a router by other nodes. The minimum value is 0.
Added in version 248.
OriginatorIntervalSec=
The value specifies the interval in seconds, unless another
time unit is specified in which batman-adv floods the network
with its protocol information. See systemd.time(7) for more
information.
Added in version 248.
GatewayBandwidthDown=
If the node is a server, this parameter is used to inform
other nodes in the network about this node's internet
connection download bandwidth in bits per second. Just enter
any number suffixed with K, M, G or T (base 1000) and the
batman-adv module will propagate the entered value in the
mesh.
Added in version 248.
GatewayBandwidthUp=
If the node is a server, this parameter is used to inform
other nodes in the network about this node's internet
connection upload bandwidth in bits per second. Just enter any
number suffixed with K, M, G or T (base 1000) and the
batman-adv module will propagate the entered value in the
mesh.
Added in version 248.
RoutingAlgorithm=
This can be either "batman-v" or "batman-iv" and describes
which routing_algo of batctl(8) to use. The algorithm cannot
be changed after interface creation. Defaults to "batman-v".
Added in version 248.
The [IPoIB] section only applies for netdevs of kind "ipoib" and
accepts the following keys:
PartitionKey=
Takes an integer in the range 1...0xffff, except for 0x8000.
Defaults to unset, and the kernel's default is used.
Added in version 250.
Mode=
Takes one of the special values "datagram" or "connected".
Defaults to unset, and the kernel's default is used.
When "datagram", the Infiniband unreliable datagram (UD)
transport is used, and so the interface MTU is equal to the IB
L2 MTU minus the IPoIB encapsulation header (4 bytes). For
example, in a typical IB fabric with a 2K MTU, the IPoIB MTU
will be 2048 - 4 = 2044 bytes.
When "connected", the Infiniband reliable connected (RC)
transport is used. Connected mode takes advantage of the
connected nature of the IB transport and allows an MTU up to
the maximal IP packet size of 64K, which reduces the number of
IP packets needed for handling large UDP datagrams, TCP
segments, etc and increases the performance for large
messages.
Added in version 250.
IgnoreUserspaceMulticastGroups=
Takes a boolean value. When true, the kernel ignores multicast
groups handled by userspace. Defaults to unset, and the
kernel's default is used.
Added in version 250.
The [WLAN] section only applies to WLAN interfaces, and accepts
the following keys:
PhysicalDevice=
Specifies the name or index of the physical WLAN device (e.g.
"0" or "phy0"). The list of the physical WLAN devices that
exist on the host can be obtained by iw phy command. This
option is mandatory.
Added in version 251.
Type=
Specifies the type of the interface. Takes one of the
"ad-hoc", "station", "ap", "ap-vlan", "wds", "monitor",
"mesh-point", "p2p-client", "p2p-go", "p2p-device", "ocb", and
"nan". This option is mandatory.
Added in version 251.
WDS=
Enables the Wireless Distribution System (WDS) mode on the
interface. The mode is also known as the "4 address mode".
Takes a boolean value. Defaults to unset, and the kernel's
default will be used.
Added in version 251.
Example 1. /etc/systemd/network/25-bridge.netdev
[NetDev]
Name=bridge0
Kind=bridge
Example 2. /etc/systemd/network/25-vlan1.netdev
[Match]
Virtualization=no
[NetDev]
Name=vlan1
Kind=vlan
[VLAN]
Id=1
Example 3. /etc/systemd/network/25-ipip.netdev
[NetDev]
Name=ipip-tun
Kind=ipip
MTUBytes=1480
[Tunnel]
Local=192.168.223.238
Remote=192.169.224.239
TTL=64
Example 4. /etc/systemd/network/1-fou-tunnel.netdev
[NetDev]
Name=fou-tun
Kind=fou
[FooOverUDP]
Port=5555
Protocol=4
Example 5. /etc/systemd/network/25-fou-ipip.netdev
[NetDev]
Name=ipip-tun
Kind=ipip
[Tunnel]
Independent=yes
Local=10.65.208.212
Remote=10.65.208.211
FooOverUDP=yes
FOUDestinationPort=5555
Example 6. /etc/systemd/network/25-tap.netdev
[NetDev]
Name=tap-test
Kind=tap
[Tap]
MultiQueue=yes
PacketInfo=yes
Example 7. /etc/systemd/network/25-sit.netdev
[NetDev]
Name=sit-tun
Kind=sit
MTUBytes=1480
[Tunnel]
Local=10.65.223.238
Remote=10.65.223.239
Example 8. /etc/systemd/network/25-6rd.netdev
[NetDev]
Name=6rd-tun
Kind=sit
MTUBytes=1480
[Tunnel]
Local=10.65.223.238
IPv6RapidDeploymentPrefix=2602::/24
Example 9. /etc/systemd/network/25-gre.netdev
[NetDev]
Name=gre-tun
Kind=gre
MTUBytes=1480
[Tunnel]
Local=10.65.223.238
Remote=10.65.223.239
Example 10. /etc/systemd/network/25-ip6gre.netdev
[NetDev]
Name=ip6gre-tun
Kind=ip6gre
[Tunnel]
Key=123
Example 11. /etc/systemd/network/25-vti.netdev
[NetDev]
Name=vti-tun
Kind=vti
MTUBytes=1480
[Tunnel]
Local=10.65.223.238
Remote=10.65.223.239
Example 12. /etc/systemd/network/25-veth.netdev
[NetDev]
Name=veth-test
Kind=veth
[Peer]
Name=veth-peer
Example 13. /etc/systemd/network/25-bond.netdev
[NetDev]
Name=bond1
Kind=bond
[Bond]
Mode=802.3ad
TransmitHashPolicy=layer3+4
MIIMonitorSec=1s
LACPTransmitRate=fast
Example 14. /etc/systemd/network/25-dummy.netdev
[NetDev]
Name=dummy-test
Kind=dummy
MACAddress=12:34:56:78:9a:bc
Example 15. /etc/systemd/network/25-vrf.netdev
Create a VRF interface with table 42.
[NetDev]
Name=vrf-test
Kind=vrf
[VRF]
Table=42
Example 16. /etc/systemd/network/25-macvtap.netdev
Create a MacVTap device.
[NetDev]
Name=macvtap-test
Kind=macvtap
Example 17. /etc/systemd/network/25-wireguard.netdev
[NetDev]
Name=wg0
Kind=wireguard
[WireGuard]
PrivateKey=EEGlnEPYJV//kbvvIqxKkQwOiS+UENyPncC4bF46ong=
ListenPort=51820
[WireGuardPeer]
PublicKey=RDf+LSpeEre7YEIKaxg+wbpsNV7du+ktR99uBEtIiCA=
AllowedIPs=fd31:bf08:57cb::/48,192.168.26.0/24
Endpoint=wireguard.example.com:51820
Example 18. /etc/systemd/network/27-xfrm.netdev
[NetDev]
Name=xfrm0
Kind=xfrm
[Xfrm]
Independent=yes
systemd(1), systemd-networkd.service(8), systemd.link(5),
systemd.network(5), systemd-network-generator.service(8)
1. Linux Ethernet Bonding Driver HOWTO
https://docs.kernel.org/networking/bonding.html
2. RFC 2784
https://tools.ietf.org/html/rfc2784
3. IEEE 802.1Q
http://www.ieee802.org/1/pages/802.1Q.html
4. VRF
https://docs.kernel.org/networking/vrf.html
5. B.A.T.M.A.N. Advanced
https://www.open-mesh.org/projects/open-mesh/wiki
6. System and Service Credentials
https://systemd.io/CREDENTIALS
7. Distributed Overlay Virtual Ethernet (DOVE)
https://en.wikipedia.org/wiki/Distributed_Overlay_Virtual_Ethernet
8. VXLAN Group Policy
https://tools.ietf.org/html/draft-smith-vxlan-group-policy
9. Generic Protocol Extension for VXLAN
https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-07
10. Type of Service in the Internet Protocol Suite
http://tools.ietf.org/html/rfc1349
11. RFC 6437
https://tools.ietf.org/html/rfc6437
12. RFC 2460
https://tools.ietf.org/html/rfc2460
13. RFC 2473
https://tools.ietf.org/html/rfc2473#section-4.1.1
14. ip-xfrm — transform configuration
https://man7.org/linux/man-pages/man8/ip-xfrm.8.html
15. Foo over UDP
https://lwn.net/Articles/614348
16. IPv6 Rapid Deployment
https://tools.ietf.org/html/rfc5569
17. Generic UDP Encapsulation
https://lwn.net/Articles/615044
18. Virtual XFRM Interfaces
https://lwn.net/Articles/757391
This page is part of the systemd (systemd system and service
manager) project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a
bug report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
This page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2025-08-11. (At that
time, the date of the most recent commit that was found in the
repository was 2025-08-11.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
systemd 258~rc2 SYSTEMD.NETDEV(5)
Pages that refer to this page: networkctl(1), systemd.link(5), systemd.network(5), systemd.directives(7), systemd.index(7), systemd.syntax(7), systemd.system-credentials(7), systemd-networkd.service(8), systemd-network-generator.service(8)
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