systemd.netdev(5) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | SUPPORTED NETDEV KINDS | [MATCH] SECTION OPTIONS | [NETDEV] SECTION OPTIONS | [BRIDGE] SECTION OPTIONS | [VLAN] SECTION OPTIONS | [MACVLAN] SECTION OPTIONS | [MACVTAP] SECTION OPTIONS | [IPVLAN] SECTION OPTIONS | [IPVTAP] SECTION OPTIONS | [VXLAN] SECTION OPTIONS | [GENEVE] SECTION OPTIONS | [BAREUDP] SECTION OPTIONS | [L2TP] SECTION OPTIONS | [L2TPSESSION] SECTION OPTIONS | [MACSEC] SECTION OPTIONS | [MACSECRECEIVECHANNEL] SECTION OPTIONS | [MACSECTRANSMITASSOCIATION] SECTION OPTIONS | [MACSECRECEIVEASSOCIATION] SECTION OPTIONS | [TUNNEL] SECTION OPTIONS | [FOOOVERUDP] SECTION OPTIONS | [PEER] SECTION OPTIONS | [VXCAN] SECTION OPTIONS | [TUN] SECTION OPTIONS | [TAP] SECTION OPTIONS | [WIREGUARD] SECTION OPTIONS | [WIREGUARDPEER] SECTION OPTIONS | [BOND] SECTION OPTIONS | [XFRM] SECTION OPTIONS | [VRF] SECTION OPTIONS | [BATMANADVANCED] SECTION OPTIONS | EXAMPLES | SEE ALSO | NOTES | COLOPHON

SYSTEMD.NETDEV(5)            systemd.network           SYSTEMD.NETDEV(5)

NAME         top

       systemd.netdev - Virtual Network Device configuration

SYNOPSIS         top

       netdev.netdev

DESCRIPTION         top

       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 /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 merged in the alphanumeric order and
       parsed after the main file itself has been parsed. This is useful
       to alter or add configuration settings, without having to modify
       the main configuration file. Each drop-in file must have
       appropriate section headers.

       In addition to /etc/systemd/network, drop-in ".d" directories can
       be placed in /usr/lib/systemd/network or /run/systemd/network
       directories. Drop-in files in /etc/ take precedence over those in
       /run/ which in turn take precedence over those in /usr/lib/.
       Drop-in files under any of these directories take precedence over
       the main netdev file wherever located. (Of course, since /run/ is
       temporary and /usr/lib/ is for vendors, it is unlikely drop-ins
       should be used in either of those places.)

SUPPORTED NETDEV KINDS         top

       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.     │
       ├──────────┼──────────────────────────┤
       │gretap    │ A Level 2 GRE tunnel     │
       │          │ over IPv4.               │
       ├──────────┼──────────────────────────┤
       │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.      │
       ├──────────┼──────────────────────────┤
       │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.                  │
       ├──────────┼──────────────────────────┤
       │batadvB.A.T.M.A.N. Advanced[5] │
       │          │ is a routing protocol    │
       │          │ for multi-hop mobile     │
       │          │ ad-hoc networks which    │
       │          │ operates on layer 2.     │
       └──────────┴──────────────────────────┘

[MATCH] SECTION OPTIONS         top

       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, 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.unit(5) 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.unit(5) 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.unit(5) 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.unit(5)
           for details. When prefixed with an exclamation mark ("!"),
           the result is negated. If an empty string is assigned, then
           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, then previously assigned value is
           cleared.

[NETDEV] SECTION OPTIONS         top

       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=
           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.network(5) 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-id(5).

[BRIDGE] SECTION OPTIONS         top

       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         top

       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=
           Defines a mapping of Linux internal packet priority
           (SO_PRIORITY) to VLAN header PCP field for outgoing frames.
           Takes a whitespace-separated list of unsigned integer pairs
           in the format "from"-"to", e.g., "21-7 45-5" ranges
           1–4294967294. Note that "from" must be greater than or equal
           to "to". When unset, the kernel's default will be used.

       IngressQOSMaps=
           Defines a mapping of Linux internal packet priority
           (SO_PRIORITY) to VLAN header PCP field for incoming frames.
           Takes a whitespace-separated list of unsigned integer pairs
           in the format "from"-"to", e.g., "21-7 45-5" ranges
           1–4294967294. Note that "from" must be greater than or equal
           to "to". When unset, the kernel's default will be used.

[MACVLAN] SECTION OPTIONS         top

       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         top

       The [MACVTAP] section applies for netdevs of kind "macvtap" and
       accepts the same keys as [MACVLAN].

[IPVLAN] SECTION OPTIONS         top

       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         top

       The [IPVTAP] section only applies for netdevs of kind "ipvtap"
       and accepts the same keys as [IPVLAN].

[VXLAN] SECTION OPTIONS         top

       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.

       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)[6]
           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[7] 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[8] 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 OPTIONS         top

       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.

       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 OPTIONS         top

       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         top

       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 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 OPTIONS         top

       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         top

       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         top

       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         top

       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 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 OPTIONS         top

       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         top

       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:

       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[9] 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[10]) field in
           the IPv6 header (see RFC 2460[11]), 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[12]). 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[13] 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[14]

       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[15], 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 OPTIONS         top

       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[16].
           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         top

       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         top

       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         top

       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.

[TAP] SECTION OPTIONS         top

       The [Tap] section only applies for netdevs of kind "tap", and
       accepts the same keys as the [Tun] section.

[WIREGUARD] SECTION OPTIONS         top

       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.

[WIREGUARDPEER] SECTION OPTIONS         top

       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", as in, which wireguard peer packets with a
           specific destination address are sent to, and what source
           addresses are accepted from which peer.

           To cause packets to be sent via wireguard in first place, a
           route needs to be added, as well - either in the "[Routes]"
           section on the ".network" matching the wireguard interface,
           or outside of networkd.

       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 OPTIONS         top

       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         top

       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 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[17].

[VRF] SECTION OPTIONS         top

       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         top

       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 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".

EXAMPLES         top

       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         top

       systemd(1), systemd-networkd(8), systemd.link(5),
       systemd.network(5)

NOTES         top

        1. Linux Ethernet Bonding Driver HOWTO
           https://www.kernel.org/doc/Documentation/networking/bonding.txt

        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://www.kernel.org/doc/Documentation/networking/vrf.txt

        5. B.A.T.M.A.N. Advanced
           https://www.open-mesh.org/projects/open-mesh/wiki

        6. (DVOE)
           https://en.wikipedia.org/wiki/Distributed_Overlay_Virtual_Ethernet

        7. VXLAN Group Policy
           https://tools.ietf.org/html/draft-smith-vxlan-group-policy

        8. Generic Protocol Extension for VXLAN
           https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-07

        9. Type of Service in the Internet Protocol Suite
           http://tools.ietf.org/html/rfc1349

       10. RFC 6437
           https://tools.ietf.org/html/rfc6437

       11. RFC 2460
           https://tools.ietf.org/html/rfc2460

       12. RFC 2473
           https://tools.ietf.org/html/rfc2473#section-4.1.1

       13. ip-xfrm — transform configuration
           http://man7.org/linux/man-pages/man8/ip-xfrm.8.html

       14. Foo over UDP
           https://lwn.net/Articles/614348

       15. IPv6 Rapid Deployment
           https://tools.ietf.org/html/rfc5569

       16. Generic UDP Encapsulation
           https://lwn.net/Articles/615044

       17. Virtual XFRM Interfaces
           https://lwn.net/Articles/757391

COLOPHON         top

       This page is part of the systemd (systemd system and service
       manager) project.  Information about the project can be found at
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have
       a bug report for this manual page, see
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
       This page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2021-06-20.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2021-06-19.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

systemd 249                                            SYSTEMD.NETDEV(5)

Pages that refer to this page: networkctl(1)systemd.link(5)systemd.network(5)systemd.directives(7)systemd.index(7)systemd.syntax(7)systemd-networkd.service(8)systemd-network-generator.service(8)