interfaces-bridge(5)

NAME

interfaces-bridge - Bridge extensions for the interfaces(5) file format

DESCRIPTION

Linux has support for Ethernet bridging interfaces which act like an Ethernet switch within the Linux Kernel. The following options allow to set up Ethernet bridges and adding configured interfaces to bridges.

See ip-link(8) for more details about the options listed below.

BRIDGE-RELATED OPTIONS

bridge-ports list of interfaces
    A space separated list of interfaces which should be configured as member interfaces of this bridge. This option must be set for the bridge to be configured. Set it to none to create a bridge with no ports.

bridge-hw MAC address
    Denotes the MAC address the bridge should use.

bridge-ageing seconds
    Denotes the time in seconds after which a MAC address will be removed from the Forwarding DataBase (FDB) after not having seen a frame with this source address.

bridge-vlan-aware bool
    Denotes wether or not the bridge should be aware of 802.1q VLANs. bool can be given as yes/no or 0/1. The defaul is no. See related options for configuring vlan-aware bridges, below.

SPANNING TREE RELATED BRIDGE OPTIONS

bridge-stp state
    Activates or deactivates IEEE 802.1d Spanning Tree Protocol (STP) support of the bridge. Valid values are on/off.

bridge-bridgeprio priority
    Sets the bridge's priority to priority. The priority value is a number between 0 and 65535. Lower priority values are better. The bridge with the lowest priority will be elected root bridge.

bridge-fd seconds
    Denotes the bridge forward delay in seconds. Valid values are between 2 and 30.

bridge-hello seconds
    Denotes the bridge hello time in seconds. Valid values are between 1 and 10.

bridge-maxage seconds
    Denotes the seconds until another bridge is considerd dead after reception of its last STP hello message. Valid values are between 6 and 40.

OPTIONS FOR VLAN-AWARE-BRIDGES

The following options only have an effect on vlan-aware bridges and their ports.

Unless otherwise noted, all settings can be applied on the bridge interface itself and all member port iface stanzas. If applied on the bridge interface they take effect for the bridge interface itself and might be inherited to bridge-ports depending on the compatibility settings configured in ifupdown-ng.conf(5).

Configuring VLAN options on the bridge interface might be required for setting up a VLAN interface to one of the VLANs carried within the bridge. See the EXAMPLES section for an example for this scenario.

See ifupdown-ng.conf(5) for more information about compatiblity settings mentioned below.

bridge-access vlan ID
    Configure the given vlan ID for untagged ingress and egress on this interface. The common description for this kind of configuration is called "access port".

bridge-pvid vlan ID
    Denotes the vlan ID to considered a PVID at ingress. Any untagged frames received on this interface will be assigned to this vlan ID. The default PVID is 1.

    If compatibility to ifupdown2 bridge port inheritance is active a bridge-pvid set on the bridge will be inherited to any interface configured in bridge-ports without a bridge-pvid set.

bridge-vids list of vlan IDs
    Denotes the space separated list of VLANs to be allowed tagged ingress/egress on this interface.

    If compatibility to ifupdown2 bridge port inheritance is active a bridge-vids set on the bridge will be inherited to any interface configured in bridge-ports without bridge-vids set.

bridge-allow-untagged bool
    Denotes wether or not the bridge should allow untagged frames on ingress as well as egress. If set to no untagged frames will be droppped on ingress and none will be sent. bool can be given as yes/no or 0/1. The defaul is yes.

bridge-default-pvid vlan ID
    Denotes the vlan ID that should be the default PVID for all ports on this interface. This sets the vlan_default_pvid option on the bridge and thus also applies to ports configured outside of ifupdown-ng. Set to 0 to disable.

    This option can only be used on the bridge itself, not on its ports. The default is 1.

EXAMPLES

A simple layer 2 only bridge:

    auto br0
    iface br0
    	bridge-ports eth0 veth-vm1 tap0
    	bridge-fd 0
    	bridge-stp off

A bridge with layer 3 configuration:

    auto br0
    iface br0
    	bridge-ports eth0 veth-vm1 tap0
    	bridge-fd 0
    	bridge-stp off
    	#
    	address 192.0.2.42/24
    	address 2001:db8::42/64

A layer 2 only vlan-aware bridge:

    auto bond0
    iface bond0
    	bond-members eth0 eth1
    	bridge-vids 23 42 84 1337
    auto br0
    iface br0
    	bridge-ports bond0

A vlan-aware bridge with a VLAN interface on top:

    auto eth0
    iface eth0
    	bridge-vids 23 42 84 1337
    auto br0
    iface br0
    	bridge-ports eth0
    	bridge-vlan-aware yes
    	bridge-vids 42
    auto vlan42
    iface vlan42
    	vlan-raw-device br0
    	#
    	address 192.0.2.42/24
    	address 2001:db8::42/64

SEE ALSO

interfaces(5) ifupdown-ng.conf(5) ip-link(8) bridge(8)

AUTHORS

Maximilian Wilhelm <max@sdn.clinic>