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 | [VXLAN] SECTION OPTIONS | [GENEVE] SECTION OPTIONS | [TUNNEL] SECTION OPTIONS | [PEER] SECTION OPTIONS | [TUN] SECTION OPTIONS | [TAP] SECTION OPTIONS | [BOND] SECTION OPTIONS | EXAMPLE | 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

       Network setup is performed by systemd-networkd(8).
       The main Virtual Network Device file must have the extension .netdev;
       other extensions are ignored. Virtual network devices are created as
       soon as networkd is started. If a netdev with the specified name
       already exists, networkd will use that as-is rather than create its
       own. Note that the settings of the pre-existing netdev will not be
       changed by networkd.
       The .netdev files are read from the files located in the system
       network directory /usr/lib/systemd/network, the volatile runtime
       network directory /run/systemd/network and the local administration
       network directory /etc/systemd/network. All configuration files are
       collectively sorted and processed in lexical order, regardless of the
       directories in which they live. However, files with identical
       filenames replace each other. Files in /etc have the highest
       priority, files in /run take precedence over files with the same name
       in /usr/lib. This can be used to override a system-supplied
       configuration file with a local file if needed. As a special case, an
       empty file (file size 0) or symlink with the same name pointing to
       /dev/null disables the configuration file entirely (it is "masked").
       Along with the netdev file foo.netdev, a "drop-in" directory
       foo.netdev.d/ may exist. All files with the suffix ".conf" from this
       directory will be parsed after the file itself is parsed. This is
       useful to alter or add configuration settings, without having to
       modify the main configuration file. Each drop-in file must have
       appropriate section headers.
       In addition to /etc/systemd/network, drop-in ".d" directories can be
       placed in /usr/lib/systemd/network or /run/systemd/network
       directories. Drop-in files in /etc take precedence over those in /run
       which in turn take precedence over those in /usr/lib. Drop-in files
       under any of these directories take precedence over the main netdev
       file wherever located. (Of course, since /run is temporary and
       /usr/lib is for vendors, it is unlikely drop-ins should be used in
       either of those places.)

SUPPORTED NETDEV 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.Local             │
       │          │ configuration             │
       ├──────────┼───────────────────────────┤
       │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.                     │
       ├──────────┼───────────────────────────┤
       │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.  │
       ├──────────┼───────────────────────────┤
       │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.            │
       ├──────────┼───────────────────────────┤
       │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.      │
       └──────────┴───────────────────────────┘

[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.
       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.
       KernelCommandLine=
           Checks whether a specific kernel command line option is set (or
           if prefixed with the exclamation mark unset). See
           "ConditionKernelCommandLine=" in systemd.unit(5) for details.
       Architecture=
           Checks whether the system is running on a specific architecture.
           See "ConditionArchitecture=" in systemd.unit(5) for details.

[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 option is
           compulsory.
       Kind=
           The netdev kind. This option 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. This key is not currently supported for "tun" or
           "tap" devices.
       MACAddress=
           The MAC address to use for the device. If none is given, one is
           generated based on the interface name and the machine-id(5). This
           key is not currently supported for "tun" or "tap" devices.

[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.
       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=
           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 setting applies.
       MulticastSnooping=
           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 setting
           applies.
       VLANFiltering=
           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 setting
           applies.
       STP=
           A boolean. This enables the bridge's Spanning Tree Protocol
           (STP). When unset, the kernel's default setting applies.

[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 option
           is compulsory.
       GVRP=
           The Generic VLAN Registration Protocol (GVRP) is a protocol that
           allows automatic learning of VLANs on a network. A boolean. When
           unset, the kernel's default setting applies.
       MVRP=
           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. A boolean. When unset, the kernel's default setting
           applies.
       LooseBinding=
           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. A boolean. When unset, the kernel's
           default setting applies.
       ReorderHeader=
           The VLAN reorder header is set VLAN interfaces behave like
           physical interfaces. A boolean. When unset, the kernel's default
           setting applies.

[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", and "passthru".

[MACVTAP] SECTION OPTIONS         top

       The "[MACVTAP]" section applies for netdevs of kind "macvtap" and
       accepts the same key 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" and "L3".

[VXLAN] SECTION OPTIONS         top

       The "[VXLAN]" section only applies for netdevs of kind "vxlan", and
       accepts the following keys:
       Id=
           The VXLAN ID to use.
       Remote=
           Configures destination multicast group IP address.
       Local=
           Configures local IP 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. N is a number in the range 1–255. 0 is a special value
           meaning that packets inherit the TTL value.
       MacLearning=
           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=
           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)[5] clients. Defaults
           to false.
       L2MissNotification=
           A boolean. When true, enables netlink LLADDR miss notifications.
       L3MissNotification=
           A boolean. When true, enables netlink IP address miss
           notifications.
       RouteShortCircuit=
           A boolean. When true, route short circuiting is turned on.
       UDPChecksum=
           A boolean. When true, transmitting UDP checksums when doing
           VXLAN/IPv4 is turned on.
       UDP6ZeroChecksumTx=
           A boolean. When true, sending zero checksums in VXLAN/IPv6 is
           turned on.
       UDP6ZeroChecksumRx=
           A boolean. When true, receiving zero checksums in VXLAN/IPv6 is
           turned on.
       RemoteChecksumTx=
           A boolean. When true, remote transmit checksum offload of VXLAN
           is turned on.
       RemoteChecksumRx=
           A boolean. When true, remote receive checksum offload in VXLAN is
           turned on.
       GroupPolicyExtension=
           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[6] document. Defaults to false.
       DestinationPort=
           Configures the default destination UDP port on a per-device
           basis. If destination port is not specified then Linux kernel
           default will be used. Set destination port 4789 to get the IANA
           assigned value. If not set or if the destination port is assigned
           the empty string the default port of 4789 is used.
       PortRange=
           Configures VXLAN port range. VXLAN bases source UDP port based on
           flow to help the receiver to be able to load balance based on
           outer header flow. It restricts the port range to the normal UDP
           local ports, and allows overriding via configuration.
       FlowLabel=
           Specifies the flow label to use in outgoing packets. The valid
           range is 0-1048575.

[GENEVE] SECTION OPTIONS         top

       The "[GENEVE]" section only applies for netdevs of kind "geneve", and
       accepts the following keys:
       Id=
           Specifies the Virtual Network Identifer (VNI) to use. Ranges
           [0-16777215].
       Remote=
           Specifies the unicast destination IP address to use in outgoing
           packets.
       TOS=
           Specifies the TOS value to use in outgoing packets. Ranges
           [1-255].
       TTL=
           Specifies the TTL value to use in outgoing packets. Ranges
           [1-255].
       UDPChecksum=
           A boolean. When true, specifies if UDP checksum is calculated for
           transmitted packets over IPv4.
       UDP6ZeroChecksumTx=
           A boolean. When true, skip UDP checksum calculation for
           transmitted packets over IPv6.
       UDP6ZeroChecksumRx=
           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.

[TUNNEL] SECTION OPTIONS         top

       The "[Tunnel]" section only applies for netdevs of kind "ipip",
       "sit", "gre", "gretap", "ip6gre", "ip6gretap", "vti", "vti6", and
       "ip6tnl" and accepts the following keys:
       Local=
           A static local address for tunneled packets. It must be an
           address on another interface of this host.
       Remote=
           The remote endpoint of the tunnel.
       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[7] 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: inherit.
           The default value for IPv6 tunnels is 64.
       DiscoverPathMTU=
           A boolean. When true, enables Path MTU Discovery on the tunnel.
       IPv6FlowLabel=
           Configures the 20-bit flow label (see RFC 6437[8]) field in the
           IPv6 header (see RFC 2460[9]), 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=
           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[10]). 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[11] for
           details. It is only used for VTI/VTI6 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 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 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.

[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 option is
           compulsory.
       MACAddress=
           The peer MACAddress, if not set, it is generated in the same way
           as the MAC address of the main interface.

[TUN] SECTION OPTIONS         top

       The "[Tun]" section only applies for netdevs of kind "tun", and
       accepts the following keys:
       OneQueue=
           Takes a boolean argument. Configures whether all packets are
           queued at the device (enabled), or a fixed number of packets are
           queued at the device and the rest at the "qdisc". Defaults to
           "no".
       MultiQueue=
           Takes a boolean argument. Configures whether to use multiple file
           descriptors (queues) to parallelize packets sending and
           receiving. Defaults to "no".
       PacketInfo=
           Takes a boolean argument. 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 argument. Configures IFF_VNET_HDR flag for a 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.

[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".
       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 in milliseconds. A
           value of 0 disables ARP monitoring. The default value is 0.
       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=
           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).
       MinLinks=
           Specifies the minimum number of links that must be active before
           asserting carrier. The default value is 0.
       ActiveSlave=
           A boolean. Specifies the new active slave. The "ActiveSlave="
           option is only valid for following modes: "active-backup",
           "balance-alb" and "balance-tlb". Defaults to false.
       PrimarySlave=
           A boolean. Specifies which slave is the primary device. The
           specified device will always be the active slave while it is
           available. Only when the primary is off-line will alternate
           devices be used. This is useful when one slave is preferred over
           another, e.g. when one slave has higher throughput than another.
           The "PrimarySlave=" option is only valid for following modes:
           "active-backup", "balance-alb" and "balance-tlb". Defaults to
           false.
       For more detail information see Linux Ethernet Bonding Driver
       HOWTO[1]

EXAMPLE         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/25-tap.netdev
           [NetDev]
           Name=tap-test
           Kind=tap
           [Tap]
           MultiQueue=true
           PacketInfo=true
       Example 5. /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 6. /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 7. /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 8. /etc/systemd/network/25-veth.netdev
           [NetDev]
           Name=veth-test
           Kind=veth
           [Peer]
           Name=veth-peer
       Example 9. /etc/systemd/network/25-bond.netdev
           [NetDev]
           Name=bond1
           Kind=bond
           [Bond]
           Mode=802.3ad
           TransmitHashPolicy=layer3+4
           MIIMonitorSec=1s
           LACPTransmitRate=fast
       Example 10. /etc/systemd/network/25-dummy.netdev
           [NetDev]
           Name=dummy-test
           Kind=dummy
           MACAddress=12:34:56:78:9a:bc
       Example 11. /etc/systemd/network/25-vrf.netdev
       Create a VRF interface with table 42.
           [NetDev]
           Name=vrf-test
           Kind=vrf
           [VRF]
           TableId=42
       Example 12. /etc/systemd/network/25-macvtap.netdev
       Create a MacVTap device.
           [NetDev]
           Name=macvtap-test
           Kind=macvtap

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. (DVOE)
           https://en.wikipedia.org/wiki/Distributed_Overlay_Virtual_Ethernet
        6. VXLAN Group Policy
           https://tools.ietf.org/html/draft-smith-vxlan-group-policy
        7. Type of Service in the Internet Protocol Suite
           http://tools.ietf.org/html/rfc1349
        8. RFC 6437
           https://tools.ietf.org/html/rfc6437
        9. RFC 2460
           https://tools.ietf.org/html/rfc2460
       10. RFC 2473
           https://tools.ietf.org/html/rfc2473#section-4.1.1
       11. ip-xfrm — transform configuration
           http://man7.org/linux/man-pages/man8/ip-xfrm.8.html

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 2017-07-05.  If you dis‐
       cover 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 234                                                SYSTEMD.NETDEV(5)

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