SYSTEMD.NETDEV(5) systemd.network SYSTEMD.NETDEV(5)
NAME
systemd.netdev - Virtual Network Device configuration
SYNOPSIS
netdev.netdev
DESCRIPTION
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 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 /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 (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 /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 /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 /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 KINDS
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. │
├──────────┼────────────────────────────┤
│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 an 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. │
└──────────┴────────────────────────────┘
[MATCH] SECTION OPTIONS
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.
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.
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.
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.
Credential=
Checks whether the specified credential was passed to the
systemd-networkd.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.
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.
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.
[NETDEV] SECTION OPTIONS
The [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.network(5) files.
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.
[BRIDGE] SECTION OPTIONS
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.
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 802.1q
or, 802.1ad, 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 OPTIONS
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.
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.
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.
[MACVLAN] SECTION OPTIONS
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".
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.
BroadcastMulticastQueueLength=
Specifies the length of the receive queue for broadcast/multicast
packets. An unsigned integer in the range 0...4294967294. Defaults
to unset.
[MACVTAP] SECTION OPTIONS
The [MACVTAP] section applies for netdevs of kind "macvtap" and accepts
the same keys as [MACVLAN].
[IPVLAN] SECTION OPTIONS
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".
Flags=
The IPVLAN flags to use. The supported options are
"bridge","private" and "vepa".
[IPVTAP] SECTION OPTIONS
The [IPVTAP] section only applies for netdevs of kind "ipvtap" and
accepts the same keys as [IPVLAN].
[VXLAN] SECTION OPTIONS
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.
Remote=
Configures destination IP address.
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.
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 (DOVE)[7] 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[8]
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[9] 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.
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.
[GENEVE] SECTION OPTIONS
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.
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.
[BAREUDP] SECTION OPTIONS
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.
EtherType=
Specifies the L3 protocol. Takes one of "ipv4", "ipv6", "mpls-uc"
or "mpls-mc". This is mandatory.
[L2TP] SECTION OPTIONS
The [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 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".
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 OPTIONS
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.
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 OPTIONS
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.
Encrypt=
Takes a boolean. When true, enable encryption. Defaults to unset.
[MACSECRECEIVECHANNEL] SECTION OPTIONS
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.
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 OPTIONS
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.
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 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.
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 OPTIONS
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.
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 OPTIONS
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.
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", 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".
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[10] 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[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.
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[13]). 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[14] 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 UDP[15]
FOUDestinationPort=
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[16], 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.
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.
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.
ERSPANDirection=
Specifies the ERSPAN v2 mirrored traffic's direction. Takes
"ingress" or "egress". Only used when ERSPANVersion=2. Defaults to
"ingress".
ERSPANHardwareId=
Specifies an unique identifier of the ERSPAN v2 engine. Takes an
integer in the range 0...63. Only used when ERSPANVersion=2.
Defaults to 0.
[FOOOVERUDP] SECTION OPTIONS
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".
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 OPTIONS
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.
MACAddress=
The peer MACAddress, if not set, it is generated in the same way as
the MAC address of the main interface.
[VXCAN] SECTION OPTIONS
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.
[TUN] SECTION OPTIONS
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".
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.
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".
[TAP] SECTION OPTIONS
The [Tap] section only applies for netdevs of kind "tap", and accepts
the same keys as the [Tun] section.
[WIREGUARD] SECTION OPTIONS
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)). 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.
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.
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.
[WIREGUARDPEER] SECTION OPTIONS
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 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.
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.
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.
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.
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.
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.
[BOND] SECTION OPTIONS
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".
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[1]
[XFRM] SECTION OPTIONS
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.
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[18].
[VRF] SECTION OPTIONS
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.
[BATMANADVANCED] SECTION OPTIONS
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).
Aggregation=
Takes a boolean value. Enables or disables aggregation of
originator messages. Defaults to true.
BridgeLoopAvoidance=
Takes a boolean value. Enables or disables avoidance of loops on
bridges. Defaults to true.
DistributedArpTable=
Takes a boolean value. Enables or disables the distributed ARP
table. Defaults to true.
Fragmentation=
Takes a boolean value. Enables or disables fragmentation. Defaults
to true.
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.
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.
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.
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.
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".
[IPOIB] SECTION OPTIONS
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.
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.
IgnoreUserspaceMulticastGroup=
Takes an boolean value. When true, the kernel ignores multicast
groups handled by userspace. Defaults to unset, and the kernel's
default is used.
[WLAN] SECTION OPTIONS
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.
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.
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.
EXAMPLES
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
SEE ALSO
systemd(1), systemd-networkd(8), systemd.link(5), systemd.network(5),
systemd-network-generator.service(8)
NOTES
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. (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
systemd 252 SYSTEMD.NETDEV(5)
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