1BRIDGE(8) Linux BRIDGE(8)
2
6 bridge - show / manipulate bridge addresses and devices
7
9 bridge [ OPTIONS ] OBJECT { COMMAND | help }
10 OBJECT := { link | fdb | mdb | vlan | monitor }
13 OPTIONS := { -V[ersion] | -s[tatistics] | -n[etns] name | -b[atch]
16 filename | -c[olor] | -p[retty] | -j[son] | -o[neline] }
17 bridge link set dev DEV [ cost COST ] [ priority PRIO ] [ state STATE ]
19 [ guard { on | off } ] [ hairpin { on | off } ] [ fastleave {
20 on | off } ] [ root_block { on | off } ] [ learning { on | off
21 } ] [ learning_sync { on | off } ] [ flood { on | off } ] [ hw‐
22 mode { vepa | veb } ] [ bcast_flood { on | off } ] [
23 mcast_flood { on | off } ] [ mcast_router MULTICAST_ROUTER ] [
24 mcast_to_unicast { on | off } ] [ neigh_suppress { on | off } ]
25 [ vlan_tunnel { on | off } ] [ isolated { on | off } ] [ locked
26 { on | off } ] [ backup_port DEVICE ] [ nobackup_port ] [ self
27 ] [ master ]
28 bridge link [ show ] [ dev DEV ]
30 bridge fdb { add | append | del | replace } LLADDR dev DEV { local |
32 static | dynamic } [ self ] [ master ] [ router ] [ use ] [ ex‐
33 tern_learn ] [ sticky ] [ src_vni VNI ] { [ dst IPADDR ] [ vni
34 VNI ] [ port PORT ] [ via DEVICE ] | nhid NHID }
35 bridge fdb [ [ show ] [ br BRDEV ] [ brport DEV ] [ vlan VID ] [ state
37 STATE ] [ dynamic ] ]
38 bridge fdb get [ to ] LLADDR [ br BRDEV ] { brport | dev } DEV [ vlan
40 VID ] [ vni VNI ] [ self ] [ master ] [ dynamic ]
41 bridge mdb { add | del } dev DEV port PORT grp GROUP [ src SOURCE ] [
43 permanent | temp ] [ vid VID ]
44 bridge mdb show [ dev DEV ]
46 bridge vlan { add | del } dev DEV vid VID [ tunnel_info TUNNEL_ID ] [
48 pvid ] [ untagged ] [ self ] [ master ]
49 bridge vlan set dev DEV vid VID [ state STP_STATE ] [ mcast_router MUL‐
51 TICAST_ROUTER ]
52 bridge vlan [ show | tunnelshow ] [ dev DEV ]
54 bridge vlan global set dev DEV vid VID [ mcast_snooping MULTI‐
56 CAST_SNOOPING ] [ mcast_querier MULTICAST_QUERIER ] [
57 mcast_igmp_version IGMP_VERSION ] [ mcast_mld_version MLD_VER‐
58 SION ] [ mcast_last_member_count LAST_MEMBER_COUNT ] [
59 mcast_last_member_interval LAST_MEMBER_INTERVAL ] [
60 mcast_startup_query_count STARTUP_QUERY_COUNT ] [
61 mcast_startup_query_interval STARTUP_QUERY_INTERVAL ] [
62 mcast_membership_interval MEMBERSHIP_INTERVAL ] [
63 mcast_querier_interval QUERIER_INTERVAL ] [ mcast_query_inter‐
64 val QUERY_INTERVAL ] [ mcast_query_response_interval QUERY_RE‐
65 SPONSE_INTERVAL ]
66 bridge vlan global [ show ] [ dev DEV ] [ vid VID ]
68 bridge monitor [ all | neigh | link | mdb | vlan ]
70
73 -V, -Version
74 print the version of the bridge utility and exit.
75 -s, -stats, -statistics
78 output more information. If this option is given multiple times,
79 the amount of information increases. As a rule, the information
80 is statistics or some time values.
81 -d, -details
84 print detailed information about bridge vlan filter entries or
85 MDB router ports.
86 -n, -net, -netns <NETNS>
89 switches bridge to the specified network namespace NETNS. Actu‐
90 ally it just simplifies executing of:
91 ip netns exec NETNS bridge [ OPTIONS ] OBJECT { COMMAND | help }
93 to
95 bridge -n[etns] NETNS [ OPTIONS ] OBJECT { COMMAND | help }
97 -b, -batch <FILENAME>
100 Read commands from provided file or standard input and invoke
101 them. First failure will cause termination of bridge command.
102 -force Don't terminate bridge command on errors in batch mode. If
105 there were any errors during execution of the commands, the ap‐
106 plication return code will be non zero.
107 -c[color][={always|auto|never}
110 Configure color output. If parameter is omitted or always, color
111 output is enabled regardless of stdout state. If parameter is
112 auto, stdout is checked to be a terminal before enabling color
113 output. If parameter is never, color output is disabled. If
114 specified multiple times, the last one takes precedence. This
115 flag is ignored if -json is also given.
116 -j, -json
119 Output results in JavaScript Object Notation (JSON).
120 -p, -pretty
123 When combined with -j generate a pretty JSON output.
124 -o, -oneline
127 output each record on a single line, replacing line feeds with
128 the '\' character. This is convenient when you want to count
129 records with wc(1) or to grep(1) the output.
130
134 OBJECT
135 link - Bridge port.
136 fdb - Forwarding Database entry.
139 mdb - Multicast group database entry.
142 vlan - VLAN filter list.
145 COMMAND
148 Specifies the action to perform on the object. The set of possible ac‐
149 tions depends on the object type. As a rule, it is possible to add,
150 delete and show (or list ) objects, but some objects do not allow all
151 of these operations or have some additional commands. The help command
152 is available for all objects. It prints out a list of available com‐
153 mands and argument syntax conventions.
154 If no command is given, some default command is assumed. Usually it is
156 list or, if the objects of this class cannot be listed, help.
157
160 link objects correspond to the port devices of the bridge.
161 The corresponding commands set and display port status and bridge spe‐
164 cific attributes.
165 bridge link set - set bridge specific attributes on a port
168 dev NAME
169 interface name of the bridge port
170 cost COST
173 the STP path cost of the specified port.
174 priority PRIO
177 the STP port priority. The priority value is an unsigned 8-bit
178 quantity (number between 0 and 255). This metric is used in the
179 designated port an droot port selection algorithms.
180 state STATE
183 the operation state of the port. Except state 0 (disable STP or
184 BPDU filter feature), this is primarily used by user space
185 STP/RSTP implementation. One may enter port state name (case in‐
186 sensitive), or one of the numbers below. Negative inputs are ig‐
187 nored, and unrecognized names return an error.
188 0 - port is in STP DISABLED state. Make this port completely in‐
190 active for STP. This is also called BPDU filter and could be
191 used to disable STP on an untrusted port, like a leaf virtual
192 devices.
193 1 - port is in STP LISTENING state. Only valid if STP is enabled
196 on the bridge. In this state the port listens for STP BPDUs and
197 drops all other traffic frames.
198 2 - port is in STP LEARNING state. Only valid if STP is enabled
201 on the bridge. In this state the port will accept traffic only
202 for the purpose of updating MAC address tables.
203 3 - port is in STP FORWARDING state. Port is fully active.
206 4 - port is in STP BLOCKING state. Only valid if STP is enabled
209 on the bridge. This state is used during the STP election
210 process. In this state, port will only process STP BPDUs.
211 guard on or guard off
215 Controls whether STP BPDUs will be processed by the bridge port.
216 By default, the flag is turned off allowed BPDU processing.
217 Turning this flag on will disables the bridge port if a STP BPDU
218 packet is received.
219 If running Spanning Tree on bridge, hostile devices on the net‐
221 work may send BPDU on a port and cause network failure. Setting
222 guard on will detect and stop this by disabling the port. The
223 port will be restarted if link is brought down, or removed and
224 reattached. For example if guard is enable on eth0:
225 ip link set dev eth0 down; ip link set dev eth0 up
227 hairpin on or hairpin off
230 Controls whether traffic may be send back out of the port on
231 which it was received. This option is also called reflective re‐
232 lay mode, and is used to support basic VEPA (Virtual Ethernet
233 Port Aggregator) capabilities. By default, this flag is turned
234 off and the bridge will not forward traffic back out of the re‐
235 ceiving port.
236 fastleave on or fastleave off
239 This flag allows the bridge to immediately stop multicast traf‐
240 fic on a port that receives IGMP Leave message. It is only used
241 with IGMP snooping is enabled on the bridge. By default the flag
242 is off.
243 root_block on or root_block off
246 Controls whether a given port is allowed to become root port or
247 not. Only used when STP is enabled on the bridge. By default the
248 flag is off.
249 This feature is also called root port guard. If BPDU is re‐
251 ceived from a leaf (edge) port, it should not be elected as root
252 port. This could be used if using STP on a bridge and the down‐
253 stream bridges are not fully trusted; this prevents a hostile
254 guest from rerouting traffic.
255 learning on or learning off
258 Controls whether a given port will learn MAC addresses from re‐
259 ceived traffic or not. If learning if off, the bridge will end
260 up flooding any traffic for which it has no FDB entry. By de‐
261 fault this flag is on.
262 learning_sync on or learning_sync off
265 Controls whether a given port will sync MAC addresses learned on
266 device port to bridge FDB.
267 flood on or flood off
270 Controls whether unicast traffic for which there is no FDB entry
271 will be flooded towards this given port. By default this flag is
272 on.
273 hwmode Some network interface cards support HW bridge functionality and
276 they may be configured in different modes. Currently support
277 modes are:
278 vepa - Data sent between HW ports is sent on the wire to the ex‐
280 ternal switch.
281 veb - bridging happens in hardware.
283 bcast_flood on or bcast_flood off
286 Controls flooding of broadcast traffic on the given port. By
287 default this flag is on.
288 mcast_flood on or mcast_flood off
291 Controls whether multicast traffic for which there is no MDB en‐
292 try will be flooded towards this given port. By default this
293 flag is on.
294 mcast_router MULTICAST_ROUTER
297 This flag is almost the same as the per-VLAN flag, see below,
298 except its value can only be set in the range 0-2. The default
299 is 1 where the bridge figures out automatically where an
300 IGMP/MLD querier, MRDISC capable device, or PIM router, is lo‐
301 cated. Setting this flag to 2 is useful in cases where the mul‐
302 ticast router does not indicate its presence in any meaningful
303 way (e.g. older versions of SMCRoute, or mrouted), or when there
304 is a need for forwarding both known and unknown IP multicast to
305 a secondary/backup router.
306 mcast_to_unicast on or mcast_to_unicast off
309 Controls whether a given port will replicate packets using uni‐
310 cast instead of multicast. By default this flag is off.
311 This is done by copying the packet per host and changing the
313 multicast destination MAC to a unicast one accordingly.
314 mcast_to_unicast works on top of the multicast snooping feature
316 of the bridge. Which means unicast copies are only delivered to
317 hosts which are interested in it and signalized this via
318 IGMP/MLD reports previously.
319 This feature is intended for interface types which have a more
321 reliable and/or efficient way to deliver unicast packets than
322 broadcast ones (e.g. WiFi).
323 However, it should only be enabled on interfaces where no
325 IGMPv2/MLDv1 report suppression takes place. IGMP/MLD report
326 suppression issue is usually overcome by the network daemon
327 (supplicant) enabling AP isolation and by that separating all
328 STAs.
329 Delivery of STA-to-STA IP multicast is made possible again by
331 enabling and utilizing the bridge hairpin mode, which considers
332 the incoming port as a potential outgoing port, too (see hairpin
333 option). Hairpin mode is performed after multicast snooping,
334 therefore leading to only deliver reports to STAs running a mul‐
335 ticast router.
336 neigh_suppress on or neigh_suppress off
339 Controls whether neigh discovery (arp and nd) proxy and suppres‐
340 sion is enabled on the port. By default this flag is off.
341 vlan_tunnel on or vlan_tunnel off
344 Controls whether vlan to tunnel mapping is enabled on the port.
345 By default this flag is off.
346 isolated on or isolated off
349 Controls whether a given port will be isolated, which means it
350 will be able to communicate with non-isolated ports only. By
351 default this flag is off.
352 locked on or locked off
355 Controls whether a port will be locked, meaning that hosts be‐
356 hind the port will not be able to communicate through the port
357 unless an FDB entry with the units MAC address is in the FDB.
358 The common use is that hosts are allowed access through authen‐
359 tication with the IEEE 802.1X protocol or based on whitelists or
360 like setups. By default this flag is off.
361 backup_port DEVICE
365 If the port loses carrier all traffic will be redirected to the
366 configured backup port
367 nobackup_port
370 Removes the currently configured backup port
371 self link setting is configured on specified physical device
374 master link setting is configured on the software bridge (default)
377 -t, -timestamp
380 display current time when using monitor option.
381 bridge link show - list ports configuration for all bridges.
384 This command displays port configuration and flags for all bridges.
385 To display port configuration and flags for a specific bridge, use the
387 "ip link show master <bridge_device>" command.
388
391 fdb objects contain known Ethernet addresses on a link.
392 The corresponding commands display fdb entries, add new entries, append
395 entries, and delete old ones.
396 bridge fdb add - add a new fdb entry
399 This command creates a new fdb entry.
400 LLADDR the Ethernet MAC address.
403 dev DEV
406 the interface to which this address is associated.
407 local - is a local permanent fdb entry, which means that the
409 bridge will not forward frames with this destination MAC address
410 and VLAN ID, but terminate them locally. This flag is default
411 unless "static" or "dynamic" are explicitly specified.
412 permanent - this is a synonym for "local"
415 static - is a static (no arp) fdb entry
418 dynamic - is a dynamic reachable age-able fdb entry
421 self - the operation is fulfilled directly by the driver for the
424 specified network device. If the network device belongs to a
425 master like a bridge, then the bridge is bypassed and not noti‐
426 fied of this operation (and if the device does notify the
427 bridge, it is driver-specific behavior and not mandated by this
428 flag, check the driver for more details). The "bridge fdb add"
429 command can also be used on the bridge device itself, and in
430 this case, the added fdb entries will be locally terminated (not
431 forwarded). In the latter case, the "self" flag is mandatory.
432 The flag is set by default if "master" is not specified.
433 master - if the specified network device is a port that belongs
436 to a master device such as a bridge, the operation is fulfilled
437 by the master device's driver, which may in turn notify the port
438 driver too of the address. If the specified device is a master
439 itself, such as a bridge, this flag is invalid.
440 router - the destination address is associated with a router.
443 Valid if the referenced device is a VXLAN type device and has
444 route short circuit enabled.
445 use - the address is in use. User space can use this option to
448 indicate to the kernel that the fdb entry is in use.
449 extern_learn - this entry was learned externally. This option
452 can be used to indicate to the kernel that an entry was hardware
453 or user-space controller learnt dynamic entry. Kernel will not
454 age such an entry.
455 sticky - this entry will not change its port due to learning.
458 The next command line parameters apply only when the specified device
461 DEV is of type VXLAN.
462 dst IPADDR
464 the IP address of the destination VXLAN tunnel endpoint where
465 the Ethernet MAC ADDRESS resides.
466 src_vni VNI
469 the src VNI Network Identifier (or VXLAN Segment ID) this entry
470 belongs to. Used only when the vxlan device is in external or
471 collect metadata mode. If omitted the value specified at vxlan
472 device creation will be used.
473 vni VNI
476 the VXLAN VNI Network Identifier (or VXLAN Segment ID) to use to
477 connect to the remote VXLAN tunnel endpoint. If omitted the
478 value specified at vxlan device creation will be used.
479 port PORT
482 the UDP destination PORT number to use to connect to the remote
483 VXLAN tunnel endpoint. If omitted the default value is used.
484 via DEVICE
487 device name of the outgoing interface for the VXLAN device
488 driver to reach the remote VXLAN tunnel endpoint.
489 nhid NHID
492 ecmp nexthop group for the VXLAN device driver to reach remote
493 VXLAN tunnel endpoints.
494 bridge fdb append - append a forwarding database entry
497 This command adds a new fdb entry with an already known LLADDR. Valid
498 only for multicast link layer addresses. The command adds support for
499 broadcast and multicast Ethernet MAC addresses. The Ethernet MAC ad‐
500 dress is added multiple times into the forwarding database and the
501 vxlan device driver sends a copy of the data packet to each entry
502 found.
503 The arguments are the same as with bridge fdb add.
506 bridge fdb delete - delete a forwarding database entry
509 This command removes an existing fdb entry.
510 The arguments are the same as with bridge fdb add.
513 bridge fdb replace - replace a forwarding database entry
516 If no matching entry is found, a new one will be created instead.
517 The arguments are the same as with bridge fdb add.
520 bridge fdb show - list forwarding entries.
523 This command displays the current forwarding table.
524 With the -statistics option, the command becomes verbose. It prints out
527 the last updated and last used time for each entry.
528 bridge fdb get - get bridge forwarding entry.
531 lookup a bridge forwarding table entry.
532 LLADDR the Ethernet MAC address.
535 dev DEV
538 the interface to which this address is associated.
539 brport DEV
542 the bridge port to which this address is associated. same as dev
543 above.
544 br DEV the bridge to which this address is associated.
547 self - the address is associated with the port drivers fdb. Usually
550 hardware.
551 master - the address is associated with master devices fdb. Usually
554 software (default).
555
559 mdb objects contain known IP or L2 multicast group addresses on a link.
560 The corresponding commands display mdb entries, add new entries, and
563 delete old ones.
564 bridge mdb add - add a new multicast group database entry
567 This command creates a new mdb entry.
568 dev DEV
571 the interface where this group address is associated.
572 port PORT
575 the port whose link is known to have members of this multicast
576 group.
577 grp GROUP
580 the multicast group address (IPv4, IPv6 or L2 multicast) whose
581 members reside on the link connected to the port.
582 permanent - the mdb entry is permanent. Optional for IPv4 and
584 IPv6, mandatory for L2.
585 temp - the mdb entry is temporary (default)
588 src SOURCE
592 optional source IP address of a sender for this multicast group.
593 If IGMPv3 for IPv4, or MLDv2 for IPv6 respectively, are enabled
594 it will be included in the lookup when forwarding multicast
595 traffic.
596 vid VID
599 the VLAN ID which is known to have members of this multicast
600 group.
601 bridge mdb delete - delete a multicast group database entry
604 This command removes an existing mdb entry.
605 The arguments are the same as with bridge mdb add.
608 bridge mdb show - list multicast group database entries
611 This command displays the current multicast group membership table. The
612 table is populated by IGMP and MLD snooping in the bridge driver auto‐
613 matically. It can be altered by bridge mdb add and bridge mdb del com‐
614 mands manually too.
615 dev DEV
618 the interface only whose entries should be listed. Default is to
619 list all bridge interfaces.
620 With the -details option, the command becomes verbose. It prints out
623 the ports known to have a connected router.
624 With the -statistics option, the command displays timer values for mdb
627 and router port entries.
628
631 vlan objects contain known VLAN IDs for a link.
632 The corresponding commands display vlan filter entries, add new en‐
635 tries, and delete old ones.
636 bridge vlan add - add a new vlan filter entry
639 This command creates a new vlan filter entry.
640 dev NAME
643 the interface with which this vlan is associated.
644 vid VID
647 the VLAN ID that identifies the vlan.
648 tunnel_info TUNNEL_ID
651 the TUNNEL ID that maps to this vlan. The tunnel id is set in
652 dst_metadata for every packet that belongs to this vlan (appli‐
653 cable to bridge ports with vlan_tunnel flag set).
654 pvid the vlan specified is to be considered a PVID at ingress. Any
657 untagged frames will be assigned to this VLAN.
658 untagged
661 the vlan specified is to be treated as untagged on egress.
662 self the vlan is configured on the specified physical device. Re‐
665 quired if the device is the bridge device.
666 master the vlan is configured on the software bridge (default).
669 bridge vlan delete - delete a vlan filter entry
672 This command removes an existing vlan filter entry.
673 The arguments are the same as with bridge vlan add. The pvid and un‐
676 tagged flags are ignored.
677 bridge vlan set - change vlan filter entry's options
680 This command changes vlan filter entry's options.
681 dev NAME
684 the interface with which this vlan is associated.
685 vid VID
688 the VLAN ID that identifies the vlan.
689 state STP_STATE
692 the operation state of the vlan. One may enter STP state name
693 (case insensitive), or one of the numbers below. Negative inputs
694 are ignored, and unrecognized names return an error. Note that
695 the state is set only for the vlan of the specified device, e.g.
696 if it is a bridge port then the state will be set only for the
697 vlan of the port.
698 0 - vlan is in STP DISABLED state. Make this vlan completely in‐
700 active for STP. This is also called BPDU filter and could be
701 used to disable STP on an untrusted vlan.
702 1 - vlan is in STP LISTENING state. Only valid if STP is enabled
705 on the bridge. In this state the vlan listens for STP BPDUs and
706 drops all other traffic frames.
707 2 - vlan is in STP LEARNING state. Only valid if STP is enabled
710 on the bridge. In this state the vlan will accept traffic only
711 for the purpose of updating MAC address tables.
712 3 - vlan is in STP FORWARDING state. This is the default vlan
715 state.
716 4 - vlan is in STP BLOCKING state. Only valid if STP is enabled
719 on the bridge. This state is used during the STP election
720 process. In this state, the vlan will only process STP BPDUs.
721 mcast_router MULTICAST_ROUTER
725 configure this vlan and interface's multicast router mode, note
726 that only modes 0 - 2 are available for bridge devices. A vlan
727 and interface with a multicast router will receive all multicast
728 traffic. MULTICAST_ROUTER may be either
729 0 - to disable multicast router.
731 1 - to let the system detect the presence of routers (default).
734 2 - to permanently enable multicast traffic forwarding on this
737 vlan and interface.
738 3 - to temporarily mark this vlan and port as having a multicast
741 router, i.e. enable multicast traffic forwarding. This mode is
742 available only for ports.
743 bridge vlan show - list vlan configuration.
747 This command displays the current VLAN filter table.
748 With the -details option, the command becomes verbose. It displays the
751 per-vlan options.
752 With the -statistics option, the command displays per-vlan traffic sta‐
755 tistics.
756 bridge vlan tunnelshow - list vlan tunnel mapping.
759 This command displays the current vlan tunnel info mapping.
760 bridge vlan global set - change vlan filter entry's global options
763 This command changes vlan filter entry's global options.
764 dev NAME
767 the interface with which this vlan is associated. Only bridge
768 devices are supported for global options.
769 vid VID
772 the VLAN ID that identifies the vlan.
773 mcast_snooping MULTICAST_SNOOPING
776 turn multicast snooping for VLAN entry with VLAN ID on (MULTI‐
777 CAST_SNOOPING > 0) or off (MULTICAST_SNOOPING == 0). Default is
778 on.
779 mcast_querier MULTICAST_QUERIER
782 enable (MULTICAST_QUERIER > 0) or disable (MULTICAST_QUERIER ==
783 0) IGMP/MLD querier, ie sending of multicast queries by the
784 bridge. Default is disabled.
785 mcast_igmp_version IGMP_VERSION
788 set the IGMP version. Default is 2.
789 mcast_mld_version MLD_VERSION
792 set the MLD version. Default is 1.
793 mcast_last_member_count LAST_MEMBER_COUNT
796 set multicast last member count, ie the number of queries the
797 bridge will send before stopping forwarding a multicast group
798 after a "leave" message has been received. Default is 2.
799 mcast_last_member_interval LAST_MEMBER_INTERVAL
802 interval between queries to find remaining members of a group,
803 after a "leave" message is received.
804 mcast_startup_query_count STARTUP_QUERY_COUNT
807 set the number of queries to send during startup phase. Default
808 is 2.
809 mcast_startup_query_interval STARTUP_QUERY_INTERVAL
812 interval between queries in the startup phase.
813 mcast_membership_interval MEMBERSHIP_INTERVAL
816 delay after which the bridge will leave a group, if no member‐
817 ship reports for this group are received.
818 mcast_querier_interval QUERIER_INTERVAL
821 interval between queries sent by other routers. If no queries
822 are seen after this delay has passed, the bridge will start to
823 send its own queries (as if mcast_querier was enabled).
824 mcast_query_interval QUERY_INTERVAL
827 interval between queries sent by the bridge after the end of the
828 startup phase.
829 mcast_query_response_interval QUERY_RESPONSE_INTERVAL
832 set the Max Response Time/Maximum Response Delay for IGMP/MLD
833 queries sent by the bridge.
834 bridge vlan global show - list global vlan options.
837 This command displays the global VLAN options for each VLAN entry.
838 dev DEV
841 the interface only whose VLAN global options should be listed.
842 Default is to list all bridge interfaces.
843 vid VID
846 the VLAN ID only whose global options should be listed. Default
847 is to list all vlans.
848
851 The bridge utility can monitor the state of devices and addresses con‐
852 tinuously. This option has a slightly different format. Namely, the
853 monitor command is the first in the command line and then the object
854 list follows:
855 bridge monitor [ all | OBJECT-LIST ]
857 OBJECT-LIST is the list of object types that we want to monitor. It
859 may contain link, fdb, vlan and mdb. If no file argument is given,
860 bridge opens RTNETLINK, listens on it and dumps state changes in the
861 format described in previous sections.
862 If a file name is given, it does not listen on RTNETLINK, but opens the
865 file containing RTNETLINK messages saved in binary format and dumps
866 them.
867
870 This command uses facilities added in Linux 3.0.
871 Although the forwarding table is maintained on a per-bridge device ba‐
873 sis the bridge device is not part of the syntax. This is a limitation
874 of the underlying netlink neighbour message protocol. When displaying
875 the forwarding table, entries for all bridges are displayed.
876 Add/delete/modify commands determine the underlying bridge device based
877 on the bridge to which the corresponding ethernet device is attached.
878
882 ip(8)
883
885 Please direct bugreports and patches to: <netdev@vger.kernel.org>
886
889 Original Manpage by Stephen Hemminger
890iproute2 1 August 2012 BRIDGE(8)