systemd.networksystemdsystemd.netdev5systemd.netdevVirtual Network Device configurationnetdev.netdevDescriptionA plain ini-style text file that encodes configuration about a virtual network device, used by
systemd-networkd8.
See systemd.syntax7
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 networkd is
started. If a netdev with the specified name already exists, networkd will use that as-is rather
than create its own. Note that the settings of the pre-existing netdev will not be changed by
networkd.The .netdev files are read from the files located in the system
network directory /usr/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 lexical order, regardless of the directories in which they live.
However, files with identical filenames replace each other. 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 parsed after the file itself is 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.)Supported netdev kindsThe following kinds of virtual network devices may be
configured in .netdev files:
Supported kinds of virtual network devicesKindDescriptionbondA bond device is an aggregation of all its slave devices. See Linux Ethernet Bonding Driver HOWTO for details.bridgeA bridge device is a software switch, and each of its slave devices and the bridge itself are ports of the switch.dummyA dummy device drops all packets sent to it.greA Level 3 GRE tunnel over IPv4. See RFC 2784 for details.gretapA Level 2 GRE tunnel over IPv4.erspanERSPAN 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.ip6greA Level 3 GRE tunnel over IPv6.ip6tnlAn IPv4 or IPv6 tunnel over IPv6ip6gretapA Level 2 GRE tunnel over IPv6.ipipAn IPv4 over IPv4 tunnel.ipvlanAn IPVLAN device is a stacked device which receives packets from its underlying device based on IP address filtering.ipvtapAn 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.macvlanA macvlan device is a stacked device which receives packets from its underlying device based on MAC address filtering.macvtapA macvtap device is a stacked device which receives packets from its underlying device based on MAC address filtering.sitAn IPv6 over IPv4 tunnel.tapA persistent Level 2 tunnel between a network device and a device node.tunA persistent Level 3 tunnel between a network device and a device node.vethAn Ethernet tunnel between a pair of network devices.vlanA VLAN is a stacked device which receives packets from its underlying device based on VLAN tagging. See IEEE 802.1Q for details.vtiAn IPv4 over IPSec tunnel.vti6An IPv6 over IPSec tunnel.vxlanA virtual extensible LAN (vxlan), for connecting Cloud computing deployments.geneveA GEneric NEtwork Virtualization Encapsulation (GENEVE) netdev driver.l2tpA 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 itselfmacsecMedia 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.vrfA Virtual Routing and Forwarding (VRF) interface to create separate routing and forwarding domains.vcanThe virtual CAN driver (vcan). Similar to the network loopback devices, vcan offers a virtual local CAN interface.vxcanThe 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.
wireguardWireGuard Secure Network Tunnel.nlmonA Netlink monitor device. Use an nlmon device when you want to monitor system Netlink messages.fouFoo-over-UDP tunneling.xfrmA 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 an UDP tunnel.
[Match] Section OptionsA 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.unit5
for details. When prefixed with an exclamation mark (!), the result is negated.
If an empty string is assigned, then previously assigned value is cleared.
Virtualization=Checks whether the system is executed in a virtualized environment and optionally test
whether it is a specific implementation. See ConditionVirtualization= in
systemd.unit5
for details. When prefixed with an exclamation mark (!), the result is negated.
If an empty string is assigned, then previously assigned value is cleared.
KernelCommandLine=Checks whether a specific kernel command line option is set. See
ConditionKernelCommandLine= in
systemd.unit5
for details. When prefixed with an exclamation mark (!), the result is negated.
If an empty string is assigned, then previously assigned value is cleared.
KernelVersion=Checks whether the kernel version (as reported by uname -r) matches a
certain expression. See ConditionKernelVersion= in
systemd.unit5
for details. When prefixed with an exclamation mark (!), the result is negated.
If an empty string is assigned, then previously assigned value is cleared.
Architecture=Checks whether the system is running on a specific architecture. See
ConditionArchitecture= in
systemd.unit5
for details. When prefixed with an exclamation mark (!), the result is negated.
If an empty string is assigned, then previously assigned value is cleared.
[NetDev] Section OptionsThe [NetDev] section accepts the
following keys:Description=A free-form description of the netdev.Name=The interface name used when creating the netdev.
This setting is compulsory.Kind=The netdev kind. This setting is compulsory. See the
Supported netdev kinds section for the
valid keys.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.network5
files.MACAddress=The MAC address to use for the device. For tun or tap
devices, setting MACAddress= in the [NetDev] section is not
supported. Please specify it in [Link] section of the corresponding
systemd.network5
file. If this option is not set, vlan devices inherit the MAC address of the
physical interface. For other kind of netdevs, if this option is not set, then MAC address is
generated based on the interface name and the
machine-id5.
[Bridge] Section OptionsThe [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.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.ForwardDelaySec=ForwardDelaySec specifies the number of seconds spent in each
of the Listening and Learning states before the Forwarding state is entered.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.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.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).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.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.
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.
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.
VLANProtocol=Allows setting the protocol used for VLAN filtering. Takes
or,
, and defaults to unset and kernel's default is used.
STP=Takes a boolean. This enables the bridge's Spanning Tree Protocol (STP).
When unset, the kernel's default will be used.
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.
[VLAN] Section OptionsThe [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.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.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.
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.
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.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.[MACVLAN] Section OptionsThe [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.
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.[MACVTAP] Section OptionsThe [MACVTAP] section applies for netdevs of kind macvtap and accepts the same
keys as [MACVLAN].[IPVLAN] Section OptionsThe [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.
Flags=The IPVLAN flags to use. The supported options are
bridge,private and vepa.
[IPVTAP] Section OptionsThe [IPVTAP] section only applies for netdevs of kind ipvtap and accepts the
same keys as [IPVLAN].[VXLAN] Section OptionsThe [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.Remote=Configures destination IP address.Local=Configures local IP address.Group=Configures VXLAN multicast group IP address. All members of a VXLAN must use the same
multicast group address.TOS=The Type Of Service byte value for a vxlan interface.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.MacLearning=Takes a boolean. When true, enables dynamic MAC learning
to discover remote MAC addresses.FDBAgeingSec=The lifetime of Forwarding Database entry learnt by
the kernel, in seconds.MaximumFDBEntries=Configures maximum number of FDB entries.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
(DVOE) clients. Defaults to false.L2MissNotification=Takes a boolean. When true, enables netlink LLADDR miss
notifications.L3MissNotification=Takes a boolean. When true, enables netlink IP address miss notifications.RouteShortCircuit=Takes a boolean. When true, route short circuiting is turned
on.UDPChecksum=Takes a boolean. When true, transmitting UDP checksums when doing VXLAN/IPv4 is turned on.UDP6ZeroChecksumTx=Takes a boolean. When true, sending zero checksums in VXLAN/IPv6 is turned on.UDP6ZeroChecksumRx=Takes a boolean. When true, receiving zero checksums in VXLAN/IPv6 is turned on.RemoteChecksumTx=Takes a boolean. When true, remote transmit checksum offload of VXLAN is turned on.RemoteChecksumRx=Takes a boolean. When true, remote receive checksum offload in VXLAN is turned on.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 document. Defaults to false.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 document. If destination port is not specified and
Generic Protocol Extension is set then default port of 4790 is used. Defaults to false.DestinationPort=Configures the default destination UDP port. If the destination port is not specified then
Linux kernel default will be used. Set to 4789 to get the IANA assigned value.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.FlowLabel=Specifies the flow label to use in outgoing packets.
The valid range is 0-1048575.
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.[GENEVE] Section OptionsThe [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.Remote=Specifies the unicast destination IP address to use in outgoing packets.TOS=Specifies the TOS value to use in outgoing packets. Takes a number between 1 and 255.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.UDPChecksum=Takes a boolean. When true, specifies that UDP checksum is calculated for transmitted packets
over IPv4.UDP6ZeroChecksumTx=Takes a boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.UDP6ZeroChecksumRx=Takes a boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.DestinationPort=Specifies destination port. Defaults to 6081. If not set or assigned the empty string, the default
port of 6081 is used.FlowLabel=Specifies the flow label to use in outgoing packets.IPDoNotFragment=Accepts the same key as in [VXLAN] section.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 tunnel using
Tunnel= is required for the tunnel to be created.[BareUDP] Section OptionsThe [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.EtherType=Specifies the L3 protocol. Takes one of ipv4, ipv6, mpls-uc
or mpls-mc. This is mandatory.[L2TP] Section OptionsThe [L2TP] section only applies for
netdevs of kind l2tp, and accepts the
following keys:TunnelId=Specifies the tunnel identifier. Takes an number in the range 1–4294967295. The value used
must match the PeerTunnelId= value being used at the peer. This setting is
compulsory.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.
Remote=Specifies the IP address of the remote peer. This setting is compulsory.Local=Specifies the IP address of the local interface. Takes an IP address, or the special values
auto, static, or dynamic. When an address
is set, then the local interface must have the address. If auto, then one of the
addresses on the local interface is used. Similarly, if static or
dynamic is set, then one of the static or dynamic addresses on the local
interface is used. Defaults to auto.EncapsulationType=Specifies the encapsulation type of the tunnel. Takes one of udp or
ip.UDPSourcePort=Specifies the UDP source port to be used for the tunnel. When UDP encapsulation is selected
it's mandatory. Ignored when IP encapsulation is selected.UDPDestinationPort=Specifies destination port. When UDP encapsulation is selected it's mandatory. Ignored when IP
encapsulation is selected.UDPChecksum=Takes a boolean. When true, specifies that UDP checksum is calculated for transmitted packets
over IPv4.UDP6ZeroChecksumTx=Takes a boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.UDP6ZeroChecksumRx=Takes a boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.[L2TPSession] Section OptionsThe [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.SessionId=Specifies the session identifier. Takes an number in the range 1–4294967295. The value used
must match the SessionId= value being used at the peer. This setting is
compulsory.PeerSessionId=Specifies the peer session identifier. Takes an number in the range 1–4294967295.
The value used must match the PeerSessionId= value being used at the peer.
This setting is compulsory.Layer2SpecificHeader=Specifies layer2specific header type of the session. One of none or default. Defaults to default.[MACsec] Section OptionsThe [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.
Encrypt=Takes a boolean. When true, enable encryption. Defaults to unset.[MACsecReceiveChannel] Section OptionsThe [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.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.[MACsecTransmitAssociation] Section OptionsThe [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.
KeyId=Specifies the identification for the key. Takes a number between 0-255. This option
is compulsory, and is not set by default.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.KeyFile=Takes a 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.Activate=Takes a boolean. If enabled, then the security association is activated. Defaults to
unset.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.[MACsecReceiveAssociation] Section OptionsThe [MACsecReceiveAssociation] section only applies for
network devices of kind macsec, and accepts the
following keys:Port=Accepts the same key as in [MACsecReceiveChannel] section.MACAddress=Accepts the same key as in [MACsecReceiveChannel] section.PacketNumber=Accepts the same key as in [MACsecTransmitAssociation] section.KeyId=Accepts the same key as in [MACsecTransmitAssociation] section.Key=Accepts the same key as in [MACsecTransmitAssociation] section.KeyFile=Accepts the same key as in [MACsecTransmitAssociation] section.Activate=Accepts the same key as in [MACsecTransmitAssociation] section.[Tunnel] Section OptionsThe [Tunnel] section only applies for
netdevs of kind
ipip,
sit,
gre,
gretap,
ip6gre,
ip6gretap,
vti,
vti6,
ip6tnl, and
erspan and accepts
the following keys:Local=A static local address for tunneled packets. It must be an address on another interface of
this host, or the special value any.Remote=The remote endpoint of the tunnel. Takes an IP address or the special value
any.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 document.
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.DiscoverPathMTU=Takes a boolean. When true, enables Path MTU Discovery on
the tunnel.IPv6FlowLabel=Configures the 20-bit flow label (see
RFC 6437) field in the IPv6 header (see
RFC 2460), 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.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.
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).
The valid range is 0–255 and none. Defaults to 4.
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 for details. It is only used for VTI/VTI6,
GRE, GRETAP, and ERSPAN tunnels.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.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.Mode=An ip6tnl tunnel can be in one of three
modes
ip6ip6 for IPv6 over IPv6,
ipip6 for IPv4 over IPv6 or
any for either.
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".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.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.
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 UDPFOUDestinationPort=This setting specifies the UDP destination port for encapsulation.
This field is mandatory when FooOverUDP=yes, and is not set by default.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.Encapsulation=Accepts the same key as in the [FooOverUDP] section.IPv6RapidDeploymentPrefix=Reconfigure the tunnel for IPv6 Rapid
Deployment, also known as 6rd. The value is an ISP-specific IPv6 prefix with a non-zero length. Only
applicable to SIT tunnels.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.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.
ERSPANIndex=Specifies the ERSPAN index field for the interface, an integer in the range 1-1048575 associated with
the ERSPAN traffic's source port and direction. This field is mandatory.
[FooOverUDP] Section OptionsThe [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. Defaults to
FooOverUDP.
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.PeerPort=Specifies the peer port number. Defaults to unset. Note that when peer port is set
Peer= address is mandatory.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.Peer=Configures peer IP address. Note that when peer address is set PeerPort=
is mandatory.Local=Configures local IP address.[Peer] Section OptionsThe [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.MACAddress=The peer MACAddress, if not set, it is generated in
the same way as the MAC address of the main
interface.[VXCAN] Section OptionsThe [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.[Tun] Section OptionsThe [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.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.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.User=User to grant access to the
/dev/net/tun device.Group=Group to grant access to the
/dev/net/tun device.[Tap] Section OptionsThe [Tap] section only applies for
netdevs of kind tap, and accepts the same keys
as the [Tun] section.[WireGuard] Section OptionsThe [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 wg8).
This option or PrivateKeyFile= is mandatory to use WireGuard.
Note that because this information is secret, you may want to set
the permissions of the .netdev file to be owned by root:systemd-network
with a 0640 file mode.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.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.FirewallMark=Sets a firewall mark on outgoing WireGuard packets from this interface. Takes a number between 1 and 4294967295.[WireGuardPeer] Section OptionsThe [WireGuardPeer] section accepts the following
keys:PublicKey=Sets a Base64 encoded public key calculated by wg pubkey
(see wg8)
from a private key, and usually transmitted out of band to the
author of the configuration file. This option is mandatory for this
section.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.
Note that because this information is secret, you may want to set
the permissions of the .netdev file to be owned by root:systemd-network
with a 0640 file mode.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.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. 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. Endpoint=Sets an endpoint IP address or hostname, followed by a colon, and then
a port number. 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.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.[Bond] Section OptionsThe [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.
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.
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.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.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.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.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.AdSelect=Specifies the 802.3ad aggregation selection logic to use. Possible values are
stable,
bandwidth and
count.
AdActorSystemPriority=Specifies the 802.3ad actor system priority. Takes a number in the range 1—65535.AdUserPortKey=Specifies the 802.3ad user defined portion of the port key. Takes a number in the range
0–1023.AdActorSystem=Specifies the 802.3ad system MAC address. This cannot be a null or multicast address.
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.
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.
ARPIntervalSec=Specifies the ARP link monitoring frequency. A value of 0 disables ARP monitoring. The
default value is 0, and the default unit seconds.
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.
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.
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.
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.
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.
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.
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 times it is nice to allow duplicate
frames to be delivered. The default value is false (drop duplicate frames
received on inactive ports).
DynamicTransmitLoadBalancing=Takes a boolean. Specifies if dynamic shuffling of flows is enabled. Applies only
for balance-tlb mode. Defaults to unset.
MinLinks=Specifies the minimum number of links that must be active before
asserting carrier. The default value is 0.
For more detail information see
Linux Ethernet Bonding Driver HOWTO[Xfrm] Section OptionsThe [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 0-0xffffffff, defaults to 0.Independent=Takes a boolean. If false (the default), the xfrm interface must have an underlying device
which can be used for hardware offloading.For more detail information see
Virtual XFRM Interfaces.[VRF] Section OptionsThe [VRF] section only applies for
netdevs of kind vrf and accepts the
following key:Table=The numeric routing table identifier. This setting is compulsory.Examples/etc/systemd/network/25-bridge.netdev[NetDev]
Name=bridge0
Kind=bridge/etc/systemd/network/25-vlan1.netdev[Match]
Virtualization=no
[NetDev]
Name=vlan1
Kind=vlan
[VLAN]
Id=1/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/etc/systemd/network/1-fou-tunnel.netdev[NetDev]
Name=fou-tun
Kind=fou
[FooOverUDP]
Port=5555
Protocol=4
/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
/etc/systemd/network/25-tap.netdev[NetDev]
Name=tap-test
Kind=tap
[Tap]
MultiQueue=yes
PacketInfo=yes/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/etc/systemd/network/25-6rd.netdev[NetDev]
Name=6rd-tun
Kind=sit
MTUBytes=1480
[Tunnel]
Local=10.65.223.238
IPv6RapidDeploymentPrefix=2602::/24/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/etc/systemd/network/25-ip6gre.netdev[NetDev]
Name=ip6gre-tun
Kind=ip6gre
[Tunnel]
Key=123/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/etc/systemd/network/25-veth.netdev[NetDev]
Name=veth-test
Kind=veth
[Peer]
Name=veth-peer/etc/systemd/network/25-bond.netdev[NetDev]
Name=bond1
Kind=bond
[Bond]
Mode=802.3ad
TransmitHashPolicy=layer3+4
MIIMonitorSec=1s
LACPTransmitRate=fast
/etc/systemd/network/25-dummy.netdev[NetDev]
Name=dummy-test
Kind=dummy
MACAddress=12:34:56:78:9a:bc/etc/systemd/network/25-vrf.netdevCreate a VRF interface with table 42.[NetDev]
Name=vrf-test
Kind=vrf
[VRF]
Table=42/etc/systemd/network/25-macvtap.netdevCreate a MacVTap device.[NetDev]
Name=macvtap-test
Kind=macvtap
/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/etc/systemd/network/27-xfrm.netdev[NetDev]
Name=xfrm0
Kind=xfrm
[Xfrm]
Independent=yesSee Alsosystemd1,
systemd-networkd8,
systemd.link5,
systemd.network5