Provided by: systemd_249.11-0ubuntu3_amd64 bug

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, 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
       /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
       ┌──────────┬──────────────────────────────────┐
       │KindDescription                      │
       ├──────────┼──────────────────────────────────┤
       │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

       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

       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

       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=
           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

       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.

       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

       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

       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 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

       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:

       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

       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

       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.

[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.

[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.
           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

       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[17].

[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 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

       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)

NOTES

        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