NAME | SYNOPSIS | OPTIONS | BRIDGE - COMMAND SYNTAX | bridge link - bridge port | bridge fdb - forwarding database management | bridge mdb - multicast group database management | bridge vlan - VLAN filter list | bridge monitor - state monitoring | NOTES | SEE ALSO | BUGS | AUTHOR | COLOPHON

BRIDGE(8)                           Linux                          BRIDGE(8)

NAME         top

       bridge - show / manipulate bridge addresses and devices

SYNOPSIS         top

       bridge [ OPTIONS ] OBJECT { COMMAND | help }

       OBJECT := { link | fdb | mdb | vlan | monitor }

       OPTIONS := { -V[ersion] | -s[tatistics] | -n[etns] name | -b[atch]
               filename | -j[son] }

       bridge link set dev DEV  [ cost COST ] [ priority PRIO ] [ state
               STATE] [ guard { on | off } ] [ hairpin { on | off } ] [
               fastleave { on | off } ] [ root_block { on | off } ] [
               learning { on | off } ] [ learning_sync { on | off } ] [
               flood { on | off } ] [ hwmode { vepa | veb } ] [ mcast_flood
               { on | off } ] [ self ] [ master ]

       bridge link [ show ] [ dev DEV ]

       bridge fdb { add | append | del | replace } LLADDR dev DEV { local |
               static | dynamic } [ self ] [ master ] [ router ] [ use ] [
               dst IPADDR ] [ vni VNI ] [ port PORT ] [ via DEVICE ]

       bridge fdb [ show ] [ dev DEV ] [ br BRDEV ] [ brport DEV ] [ vlan
               VID ] [ state STATE ]

       bridge mdb { add | del } dev DEV port PORT grp GROUP [ permanent |
               temp ] [ vid VID ]

       bridge mdb show [ dev DEV ]

       bridge vlan { add | del } dev DEV vid VID [ pvid ] [ untagged ] [
               self ] [ master ]

       bridge vlan [ show ] [ dev DEV ]

       bridge monitor [ all | neigh | link | mdb ]

OPTIONS         top

       -V, -Version
              print the version of the bridge utility and exit.

       -s, -stats, -statistics
              output more information. If this option is given multiple
              times, the amount of information increases.  As a rule, the
              information is statistics or some time values.

       -d, -details
              print detailed information about MDB router ports.

       -n, -net, -netns <NETNS>
              switches bridge to the specified network namespace NETNS.
              Actually it just simplifies executing of:

              ip netns exec NETNS bridge [ OPTIONS ] OBJECT { COMMAND | help
              }

              to

              bridge -n[etns] NETNS [ OPTIONS ] OBJECT { COMMAND | help }

       -b, -batch <FILENAME>
              Read commands from provided file or standard input and invoke
              them.  First failure will cause termination of bridge command.

       -force Don't terminate bridge command on errors in batch mode.  If
              there were any errors during execution of the commands, the
              application return code will be non zero.

       -json  Display results in JSON format. Currently available for vlan
              and fdb.

BRIDGE - COMMAND SYNTAX         top

   OBJECT
       link   - Bridge port.

       fdb    - Forwarding Database entry.

       mdb    - Multicast group database entry.

       vlan   - VLAN filter list.

   COMMAND
       Specifies the action to perform on the object.  The set of possible
       actions depends on the object type.  As a rule, it is possible to
       add, delete and show (or list ) objects, but some objects do not
       allow all of these operations or have some additional commands. The
       help command is available for all objects. It prints out a list of
       available commands and argument syntax conventions.

       If no command is given, some default command is assumed.  Usually it
       is list or, if the objects of this class cannot be listed, help.

bridge link - bridge port         top

       link objects correspond to the port devices of the bridge.

       The corresponding commands set and display port status and bridge
       specific attributes.

   bridge link set - set bridge specific attributes on a port
       dev NAME
              interface name of the bridge port

       cost COST
              the STP path cost of the specified port.

       priority PRIO
              the STP port priority. The priority value is an unsigned 8-bit
              quantity (number between 0 and 255). This metric is used in
              the designated port an droot port selectio algorithms.

       state STATE
              the operation state of the port. This is primarily used by
              user space STP/RSTP implementation. One may enter a lowercased
              port state name, or one of the numbers below. Negative inputs
              are ignored, and unrecognized names return an error.

              0 - port is DISABLED. Make this port completely inactive.

              1 - STP LISTENING state. Only valid if STP is enabled on the
              bridge. In this state the port listens for STP BPDUs and drops
              all other traffic frames.

              2 - STP LEARNING state. Only valid if STP is enabled on the
              bridge. In this state the port will accept traffic only for
              the purpose of updating MAC address tables.

              3 - STP FORWARDING state. Port is fully active.

              4 - STP BLOCKING state. Only valid if STP is enabled on the
              bridge. This state is used during the STP election process. In
              this state, port will only process STP BPDUs.

       guard on or guard off
              Controls whether STP BPDUs will be processed by the bridge
              port. By default, the flag is turned off allowed BPDU
              processing. Turning this flag on will cause the port to stop
              processing STP BPDUs.

       hairpin on or hairpin off
              Controls whether traffic may be send back out of the port on
              which it was received. By default, this flag is turned off and
              the bridge will not forward traffic back out of the receiving
              port.

       fastleave on or fastleave off
              This flag allows the bridge to immediately stop multicast
              traffic on a port that receives IGMP Leave message. It is only
              used with IGMP snooping is enabled on the bridge. By default
              the flag is off.

       root_block on or root_block off
              Controls whether a given port is allowed to become root port
              or not. Only used when STP is enabled on the bridge. By
              default the flag is off.

       learning on or learning off
              Controls whether a given port will learn MAC addresses from
              received traffic or not. If learning if off, the bridge will
              end up flooding any traffic for which it has no FDB entry. By
              default this flag is on.

       learning_sync on or learning_sync off
              Controls whether a given port will sync MAC addresses learned
              on device port to bridge FDB.

       flooding on or flooding off
              Controls whether a given port will flood unicast traffic for
              which there is no FDB entry. By default this flag is on.

       hwmode Some network interface cards support HW bridge functionality
              and they may be configured in different modes. Currently
              support modes are:

              vepa - Data sent between HW ports is sent on the wire to the
              external switch.

              veb - bridging happens in hardware.

       mcast_flood on or mcast_flood off
              Controls whether a given port will be flooded with multicast
              traffic for which there is no MDB entry. By default this flag
              is on.

       self   link setting is configured on specified physical device

       master link setting is configured on the software bridge (default)

       -t, -timestamp
              display current time when using monitor option.

   bridge link show - list bridge port configuration.
       This command displays the current bridge port configuration and
       flags.

bridge fdb - forwarding database management         top

       fdb objects contain known Ethernet addresses on a link.

       The corresponding commands display fdb entries, add new entries,
       append entries, and delete old ones.

   bridge fdb add - add a new fdb entry
       This command creates a new fdb entry.

       LLADDR the Ethernet MAC address.

       dev DEV
              the interface to which this address is associated.

              local - is a local permanent fdb entry

              static - is a static (no arp) fdb entry

              dynamic - is a dynamic reachable age-able fdb entry

              self - the address is associated with the port drivers fdb.
              Usually hardware.

              master - the address is associated with master devices fdb.
              Usually software (default).

              router - the destination address is associated with a router.
              Valid if the referenced device is a VXLAN type device and has
              route shortcircuit enabled.

              use - the address is in use. User space can use this option to
              indicate to the kernel that the fdb entry is in use.

      The next command line parameters apply only when the specified device
      DEV is of type VXLAN.

       dst IPADDR
              the IP address of the destination VXLAN tunnel endpoint where
              the Ethernet MAC ADDRESS resides.

       vni VNI
              the VXLAN VNI Network Identifier (or VXLAN Segment ID) to use
              to connect to the remote VXLAN tunnel endpoint.  If omitted
              the value specified at vxlan device creation will be used.

       port PORT
              the UDP destination PORT number to use to connect to the
              remote VXLAN tunnel endpoint.  If omitted the default value is
              used.

       via DEVICE
              device name of the outgoing interface for the VXLAN device
              driver to reach the remote VXLAN tunnel endpoint.

   bridge fdb append - append a forwarding database entry
       This command adds a new fdb entry with an already known LLADDR.
       Valid only for multicast link layer addresses.  The command adds
       support for broadcast and multicast Ethernet MAC addresses.  The
       Ethernet MAC address is added multiple times into the forwarding
       database and the vxlan device driver sends a copy of the data packet
       to each entry found.

       The arguments are the same as with bridge fdb add.

   bridge fdb delete - delete a forwarding database entry
       This command removes an existing fdb entry.

       The arguments are the same as with bridge fdb add.

   bridge fdb replace - replace a forwarding database entry
       If no matching entry is found, a new one will be created instead.

       The arguments are the same as with bridge fdb add.

   bridge fdb show - list forwarding entries.
       This command displays the current forwarding table.

       With the -statistics option, the command becomes verbose. It prints
       out the last updated and last used time for each entry.

bridge mdb - multicast group database management         top

       mdb objects contain known IP multicast group addresses on a link.

       The corresponding commands display mdb entries, add new entries, and
       delete old ones.

   bridge mdb add - add a new multicast group database entry
       This command creates a new mdb entry.

       dev DEV
              the interface where this group address is associated.

       port PORT
              the port whose link is known to have members of this multicast
              group.

       grp GROUP
              the IP multicast group address whose members reside on the
              link connected to the port.

              permanent - the mdb entry is permanent

              temp - the mdb entry is temporary (default)

       vid VID
              the VLAN ID which is known to have members of this multicast
              group.

   bridge mdb delete - delete a multicast group database entry
       This command removes an existing mdb entry.

       The arguments are the same as with bridge mdb add.

   bridge mdb show - list multicast group database entries
       This command displays the current multicast group membership table.
       The table is populated by IGMP and MLD snooping in the bridge driver
       automatically. It can be altered by bridge mdb add and bridge mdb del
       commands manually too.

       dev DEV
              the interface only whose entries should be listed. Default is
              to list all bridge interfaces.

       With the -details option, the command becomes verbose. It prints out
       the ports known to have a connected router.

       With the -statistics option, the command displays timer values for
       mdb and router port entries.

bridge vlan - VLAN filter list         top

       vlan objects contain known VLAN IDs for a link.

       The corresponding commands display vlan filter entries, add new
       entries, and delete old ones.

   bridge vlan add - add a new vlan filter entry
       This command creates a new vlan filter entry.

       dev NAME
              the interface with which this vlan is associated.

       vid VID
              the VLAN ID that identifies the vlan.

       pvid   the vlan specified is to be considered a PVID at ingress.  Any
              untagged frames will be assigned to this VLAN.

       untagged
              the vlan specified is to be treated as untagged on egress.

       self   the vlan is configured on the specified physical device.
              Required if the device is the bridge device.

       master the vlan is configured on the software bridge (default).

   bridge vlan delete - delete a vlan filter entry
       This command removes an existing vlan filter entry.

       The arguments are the same as with bridge vlan add.  The pvid and
       untagged flags are ignored.

   bridge vlan show - list vlan configuration.
       This command displays the current VLAN filter table.

       With the -statistics option, the command displays per-vlan traffic
       statistics.

bridge monitor - state monitoring         top

       The bridge utility can monitor the state of devices and addresses
       continuously. This option has a slightly different format.  Namely,
       the monitor command is the first in the command line and then the
       object list follows:

       bridge monitor [ all | OBJECT-LIST ]

       OBJECT-LIST is the list of object types that we want to monitor.  It
       may contain link, fdb, and mdb.  If no file argument is given, bridge
       opens RTNETLINK, listens on it and dumps state changes in the format
       described in previous sections.

       If a file name is given, it does not listen on RTNETLINK, but opens
       the file containing RTNETLINK messages saved in binary format and
       dumps them.

NOTES         top

       This command uses facilities added in Linux 3.0.

       Although the forwarding table is maintained on a per-bridge device
       basis the bridge device is not part of the syntax. This is a
       limitation of the underlying netlink neighbour message protocol. When
       displaying the forwarding table, entries for all bridges are
       displayed.  Add/delete/modify commands determine the underlying
       bridge device based on the bridge to which the corresponding ethernet
       device is attached.

SEE ALSO         top

       ip(8)

BUGS         top

       Please direct bugreports and patches to: <netdev@vger.kernel.org>

AUTHOR         top

       Original Manpage by Stephen Hemminger

COLOPHON         top

       This page is part of the iproute2 (utilities for controlling TCP/IP
       networking and traffic) project.  Information about the project can
       be found at 
       ⟨http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2⟩.
       If you have a bug report for this manual page, send it to
       netdev@vger.kernel.org, shemminger@osdl.org.  This page was obtained
       from the project's upstream Git repository 
       ⟨git://git.kernel.org/pub/scm/linux/kernel/git/shemminger/iproute2.git⟩
       on 2017-03-13.  If you discover any rendering problems in this HTML
       version of the page, or you believe there is a better or more up-to-
       date source for the page, or you have corrections or improvements to
       the information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

iproute2                        1 August 2012                      BRIDGE(8)