.\" Generated by scdoc 1.11.3 .\" Complete documentation for this program is not available as a GNU info page .ie \n(.g .ds Aq \(aq .el .ds Aq ' .nh .ad l .\" Begin generated content: .TH "interfaces-bridge" "5" "2024-05-06" .PP .SH NAME .PP \fBinterfaces-bridge\fR - Bridge extensions for the interfaces(5) file format .PP .SH DESCRIPTION .PP 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.\& .PP See \fBip-link\fR(8) for more details about the options listed below.\& .PP .SH BRIDGE-RELATED OPTIONS .PP \fBbridge-ports\fR \fIlist of interfaces\fR .RS 4 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.\& .PP .RE \fBbridge-hw\fR \fIMAC address\fR .RS 4 Denotes the \fIMAC address\fR the bridge should use.\& .PP .RE \fBbridge-ageing\fR \fIseconds\fR .RS 4 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.\& .PP .RE \fBbridge-vlan-aware\fR \fIbool\fR .RS 4 Denotes wether or not the bridge should be aware of 802.\&1q VLANs.\& \fIbool\fR can be given as \fIyes\fR/\fIno\fR or \fI0\fR/\fI1\fR.\& The defaul is \fIno\fR.\& See related options for configuring vlan-aware bridges, below.\& .PP .RE .SH SPANNING TREE RELATED BRIDGE OPTIONS .PP \fBbridge-stp\fR \fIstate\fR .RS 4 Activates or deactivates IEEE 802.\&1d Spanning Tree Protocol (STP) support of the bridge.\& Valid values are \fIon\fR/\fIoff\fR.\& .PP .RE \fBbridge-bridgeprio\fR \fIpriority\fR .RS 4 Sets the bridge'\&s priority to \fIpriority\fR.\& The priority value is a number between 0 and 65535.\& Lower priority values are better.\& The bridge with the lowest priority will be elected \fIroot bridge\fR.\& .PP .RE \fBbridge-fd\fR \fIseconds\fR .RS 4 Denotes the bridge forward delay in seconds.\& Valid values are between 2 and 30.\& .PP .RE \fBbridge-hello\fR \fIseconds\fR .RS 4 Denotes the bridge hello time in seconds.\& Valid values are between 1 and 10.\& .PP .RE \fBbridge-maxage\fR \fIseconds\fR .RS 4 Denotes the seconds until another bridge is considerd dead after reception of its last STP hello message.\& Valid values are between 6 and 40.\& .PP .RE .SH OPTIONS FOR VLAN-AWARE-BRIDGES .PP The following options only have an effect on vlan-aware bridges and their ports.\& .PP 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 \fIbridge-ports\fR depending on the compatibility settings configured in \fBifupdown-ng.\&conf\fR(5).\& .PP 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.\& .PP See \fBifupdown-ng.\&conf\fR(5) for more information about compatiblity settings mentioned below.\& .PP \fBbridge-access\fR \fIvlan ID\fR .RS 4 Configure the given \fIvlan ID\fR for untagged ingress and egress on this interface.\& The common description for this kind of configuration is called "access port".\& .PP .RE \fBbridge-pvid\fR \fIvlan ID\fR .RS 4 Denotes the \fIvlan ID\fR to considered a PVID at ingress.\& Any untagged frames received on this interface will be assigned to this \fIvlan ID\fR.\& The default PVID is \fI1\fR.\& .PP If compatibility to ifupdown2 bridge port inheritance is active a \fIbridge-pvid\fR set on the bridge will be inherited to any interface configured in \fIbridge-ports\fR without a \fIbridge-pvid\fR set.\& .PP .RE \fBbridge-vids\fR \fIlist of vlan IDs\fR .RS 4 Denotes the space separated list of VLANs to be allowed tagged ingress/egress on this interface.\& .PP If compatibility to ifupdown2 bridge port inheritance is active a \fIbridge-vids\fR set on the bridge will be inherited to any interface configured in \fIbridge-ports\fR without \fIbridge-vids\fR set.\& .PP .RE \fBbridge-allow-untagged\fR \fIbool\fR .RS 4 Denotes wether or not the bridge should allow untagged frames on ingress as well as egress.\& If set to \fIno\fR untagged frames will be droppped on ingress and none will be sent.\& \fIbool\fR can be given as \fIyes\fR/\fIno\fR or \fI0\fR/\fI1\fR.\& The defaul is \fIyes\fR.\& .PP .RE .SH EXAMPLES .PP A simple layer 2 only bridge: .PP .nf .RS 4 auto br0 iface br0 bridge-ports eth0 veth-vm1 tap0 bridge-fd 0 bridge-stp off .fi .RE .PP A bridge with layer 3 configuration: .PP .nf .RS 4 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 .fi .RE .PP A layer 2 only vlan-aware bridge: .PP .nf .RS 4 auto bond0 iface bond0 bond-members eth0 eth1 bridge-vids 23 42 84 1337 auto br0 iface br0 bridge-ports bond0 .fi .RE .PP A vlan-aware bridge with a VLAN interface on top: .PP .nf .RS 4 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 .fi .RE .PP .SH SEE ALSO .PP \fBinterfaces\fR(5) \fBifupdown-ng.\&conf\fR(5) \fBip-link\fR(8) \fBbridge\fR(8) .PP .SH AUTHORS .PP Maximilian Wilhelm