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[lor] | -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 } ] [
22 hwmode { vepa | veb } ] [ mcast_flood { on | off } ] [
23 mcast_to_unicast { on | off } ] [ neigh_suppress { on | off } ]
24 [ vlan_tunnel { on | off } ] [ isolated { on | off } ] [
25 backup_port DEVICE ] [ nobackup_port ] [ self ] [ master ]
26 bridge link [ show ] [ dev DEV ]
28 bridge fdb { add | append | del | replace } LLADDR dev DEV { local |
30 static | dynamic } [ self ] [ master ] [ router ] [ use ] [
31 extern_learn ] [ sticky ] [ dst IPADDR ] [ src_vni VNI ] [ vni
32 VNI ] [ port PORT ] [ via DEVICE ]
33 bridge fdb [ show ] [ dev DEV ] [ br BRDEV ] [ brport DEV ] [ vlan VID
35 ] [ state STATE ]
36 bridge fdb get LLADDR [ dev DEV ] [ br BRDEV ] [ vlan VID ] [ self ] [
38 master ]
39 bridge mdb { add | del } dev DEV port PORT grp GROUP [ permanent | temp
41 ] [ vid VID ]
42 bridge mdb show [ dev DEV ]
44 bridge vlan { add | del } dev DEV vid VID [ tunnel_info TUNNEL_ID ] [
46 pvid ] [ untagged ] [ self ] [ master ]
47 bridge vlan [ show | tunnelshow ] [ dev DEV ]
49 bridge monitor [ all | neigh | link | mdb ]
51
54 -V, -Version
55 print the version of the bridge utility and exit.
56 -s, -stats, -statistics
59 output more information. If this option is given multiple times,
60 the amount of information increases. As a rule, the information
61 is statistics or some time values.
62 -d, -details
65 print detailed information about MDB router ports.
66 -n, -net, -netns <NETNS>
69 switches bridge to the specified network namespace NETNS. Actu‐
70 ally it just simplifies executing of:
71 ip netns exec NETNS bridge [ OPTIONS ] OBJECT { COMMAND | help }
73 to
75 bridge -n[etns] NETNS [ OPTIONS ] OBJECT { COMMAND | help }
77 -b, -batch <FILENAME>
80 Read commands from provided file or standard input and invoke
81 them. First failure will cause termination of bridge command.
82 -force Don't terminate bridge command on errors in batch mode. If
85 there were any errors during execution of the commands, the
86 application return code will be non zero.
87 -c[color][={always|auto|never}
90 Configure color output. If parameter is omitted or always, color
91 output is enabled regardless of stdout state. If parameter is
92 auto, stdout is checked to be a terminal before enabling color
93 output. If parameter is never, color output is disabled. If
94 specified multiple times, the last one takes precedence. This
95 flag is ignored if -json is also given.
96 -j, -json
99 Output results in JavaScript Object Notation (JSON).
100 -p, -pretty
103 When combined with -j generate a pretty JSON output.
104 -o, -oneline
107 output each record on a single line, replacing line feeds with
108 the '\' character. This is convenient when you want to count
109 records with wc(1) or to grep(1) the output.
110
114 OBJECT
115 link - Bridge port.
116 fdb - Forwarding Database entry.
119 mdb - Multicast group database entry.
122 vlan - VLAN filter list.
125 COMMAND
128 Specifies the action to perform on the object. The set of possible
129 actions depends on the object type. As a rule, it is possible to add,
130 delete and show (or list ) objects, but some objects do not allow all
131 of these operations or have some additional commands. The help command
132 is available for all objects. It prints out a list of available com‐
133 mands and argument syntax conventions.
134 If no command is given, some default command is assumed. Usually it is
136 list or, if the objects of this class cannot be listed, help.
137
140 link objects correspond to the port devices of the bridge.
141 The corresponding commands set and display port status and bridge spe‐
144 cific attributes.
145 bridge link set - set bridge specific attributes on a port
148 dev NAME
149 interface name of the bridge port
150 cost COST
153 the STP path cost of the specified port.
154 priority PRIO
157 the STP port priority. The priority value is an unsigned 8-bit
158 quantity (number between 0 and 255). This metric is used in the
159 designated port an droot port selectio algorithms.
160 state STATE
163 the operation state of the port. This is primarily used by user
164 space STP/RSTP implementation. One may enter a lowercased port
165 state name, or one of the numbers below. Negative inputs are
166 ignored, and unrecognized names return an error.
167 0 - port is DISABLED. Make this port completely inactive.
169 1 - STP LISTENING state. Only valid if STP is enabled on the
172 bridge. In this state the port listens for STP BPDUs and drops
173 all other traffic frames.
174 2 - STP LEARNING state. Only valid if STP is enabled on the
177 bridge. In this state the port will accept traffic only for the
178 purpose of updating MAC address tables.
179 3 - STP FORWARDING state. Port is fully active.
182 4 - STP BLOCKING state. Only valid if STP is enabled on the
185 bridge. This state is used during the STP election process. In
186 this state, port will only process STP BPDUs.
187 guard on or guard off
191 Controls whether STP BPDUs will be processed by the bridge port.
192 By default, the flag is turned off allowed BPDU processing.
193 Turning this flag on will cause the port to stop processing STP
194 BPDUs.
195 hairpin on or hairpin off
198 Controls whether traffic may be send back out of the port on
199 which it was received. By default, this flag is turned off and
200 the bridge will not forward traffic back out of the receiving
201 port.
202 fastleave on or fastleave off
205 This flag allows the bridge to immediately stop multicast traf‐
206 fic on a port that receives IGMP Leave message. It is only used
207 with IGMP snooping is enabled on the bridge. By default the flag
208 is off.
209 root_block on or root_block off
212 Controls whether a given port is allowed to become root port or
213 not. Only used when STP is enabled on the bridge. By default the
214 flag is off.
215 learning on or learning off
218 Controls whether a given port will learn MAC addresses from
219 received traffic or not. If learning if off, the bridge will end
220 up flooding any traffic for which it has no FDB entry. By
221 default this flag is on.
222 learning_sync on or learning_sync off
225 Controls whether a given port will sync MAC addresses learned on
226 device port to bridge FDB.
227 flood on or flood off
230 Controls whether a given port will flood unicast traffic for
231 which there is no FDB entry. By default this flag is on.
232 hwmode Some network interface cards support HW bridge functionality and
235 they may be configured in different modes. Currently support
236 modes are:
237 vepa - Data sent between HW ports is sent on the wire to the
239 external switch.
240 veb - bridging happens in hardware.
242 mcast_flood on or mcast_flood off
245 Controls whether a given port will flood multicast traffic for
246 which there is no MDB entry. By default this flag is on.
247 mcast_to_unicast on or mcast_to_unicast off
250 Controls whether a given port will replicate packets using uni‐
251 cast instead of multicast. By default this flag is off.
252 neigh_suppress on or neigh_suppress off
255 Controls whether neigh discovery (arp and nd) proxy and suppres‐
256 sion is enabled on the port. By default this flag is off.
257 vlan_tunnel on or vlan_tunnel off
260 Controls whether vlan to tunnel mapping is enabled on the port.
261 By default this flag is off.
262 isolated on or isolated off
265 Controls whether a given port will be isolated, which means it
266 will be able to communicate with non-isolated ports only. By
267 default this flag is off.
268 backup_port DEVICE
271 If the port loses carrier all traffic will be redirected to the
272 configured backup port
273 nobackup_port
276 Removes the currently configured backup port
277 self link setting is configured on specified physical device
280 master link setting is configured on the software bridge (default)
283 -t, -timestamp
286 display current time when using monitor option.
287 bridge link show - list bridge port configuration.
290 This command displays the current bridge port configuration and flags.
291
294 fdb objects contain known Ethernet addresses on a link.
295 The corresponding commands display fdb entries, add new entries, append
298 entries, and delete old ones.
299 bridge fdb add - add a new fdb entry
302 This command creates a new fdb entry.
303 LLADDR the Ethernet MAC address.
306 dev DEV
309 the interface to which this address is associated.
310 local - is a local permanent fdb entry
312 static - is a static (no arp) fdb entry
315 dynamic - is a dynamic reachable age-able fdb entry
318 self - the address is associated with the port drivers fdb. Usu‐
321 ally hardware.
322 master - the address is associated with master devices fdb. Usu‐
325 ally software (default).
326 router - the destination address is associated with a router.
329 Valid if the referenced device is a VXLAN type device and has
330 route shortcircuit enabled.
331 use - the address is in use. User space can use this option to
334 indicate to the kernel that the fdb entry is in use.
335 extern_learn - this entry was learned externally. This option
338 can be used to indicate to the kernel that an entry was hardware
339 or user-space controller learnt dynamic entry. Kernel will not
340 age such an entry.
341 sticky - this entry will not change its port due to learning.
344 The next command line parameters apply only when the specified device
347 DEV is of type VXLAN.
348 dst IPADDR
350 the IP address of the destination VXLAN tunnel endpoint where
351 the Ethernet MAC ADDRESS resides.
352 src_vni VNI
355 the src VNI Network Identifier (or VXLAN Segment ID) this entry
356 belongs to. Used only when the vxlan device is in external or
357 collect metadata mode. If omitted the value specified at vxlan
358 device creation will be used.
359 vni VNI
362 the VXLAN VNI Network Identifier (or VXLAN Segment ID) to use to
363 connect to the remote VXLAN tunnel endpoint. If omitted the
364 value specified at vxlan device creation will be used.
365 port PORT
368 the UDP destination PORT number to use to connect to the remote
369 VXLAN tunnel endpoint. If omitted the default value is used.
370 via DEVICE
373 device name of the outgoing interface for the VXLAN device
374 driver to reach the remote VXLAN tunnel endpoint.
375 bridge fdb append - append a forwarding database entry
378 This command adds a new fdb entry with an already known LLADDR. Valid
379 only for multicast link layer addresses. The command adds support for
380 broadcast and multicast Ethernet MAC addresses. The Ethernet MAC
381 address is added multiple times into the forwarding database and the
382 vxlan device driver sends a copy of the data packet to each entry
383 found.
384 The arguments are the same as with bridge fdb add.
387 bridge fdb delete - delete a forwarding database entry
390 This command removes an existing fdb entry.
391 The arguments are the same as with bridge fdb add.
394 bridge fdb replace - replace a forwarding database entry
397 If no matching entry is found, a new one will be created instead.
398 The arguments are the same as with bridge fdb add.
401 bridge fdb show - list forwarding entries.
404 This command displays the current forwarding table.
405 With the -statistics option, the command becomes verbose. It prints out
408 the last updated and last used time for each entry.
409 bridge fdb get - get bridge forwarding entry.
412 lookup a bridge forwarding table entry.
413 LLADDR the Ethernet MAC address.
416 dev DEV
419 the interface to which this address is associated.
420 brport DEV
423 the bridge port to which this address is associated. same as dev
424 above.
425 br DEV the bridge to which this address is associated.
428 self - the address is associated with the port drivers fdb. Usually
431 hardware.
432 master - the address is associated with master devices fdb. Usually
435 software (default).
436
440 mdb objects contain known IP multicast group addresses on a link.
441 The corresponding commands display mdb entries, add new entries, and
444 delete old ones.
445 bridge mdb add - add a new multicast group database entry
448 This command creates a new mdb entry.
449 dev DEV
452 the interface where this group address is associated.
453 port PORT
456 the port whose link is known to have members of this multicast
457 group.
458 grp GROUP
461 the IP multicast group address whose members reside on the link
462 connected to the port.
463 permanent - the mdb entry is permanent
465 temp - the mdb entry is temporary (default)
468 vid VID
472 the VLAN ID which is known to have members of this multicast
473 group.
474 bridge mdb delete - delete a multicast group database entry
477 This command removes an existing mdb entry.
478 The arguments are the same as with bridge mdb add.
481 bridge mdb show - list multicast group database entries
484 This command displays the current multicast group membership table. The
485 table is populated by IGMP and MLD snooping in the bridge driver auto‐
486 matically. It can be altered by bridge mdb add and bridge mdb del com‐
487 mands manually too.
488 dev DEV
491 the interface only whose entries should be listed. Default is to
492 list all bridge interfaces.
493 With the -details option, the command becomes verbose. It prints out
496 the ports known to have a connected router.
497 With the -statistics option, the command displays timer values for mdb
500 and router port entries.
501
504 vlan objects contain known VLAN IDs for a link.
505 The corresponding commands display vlan filter entries, add new
508 entries, and delete old ones.
509 bridge vlan add - add a new vlan filter entry
512 This command creates a new vlan filter entry.
513 dev NAME
516 the interface with which this vlan is associated.
517 vid VID
520 the VLAN ID that identifies the vlan.
521 tunnel_info TUNNEL_ID
524 the TUNNEL ID that maps to this vlan. The tunnel id is set in
525 dst_metadata for every packet that belongs to this vlan (appli‐
526 cable to bridge ports with vlan_tunnel flag set).
527 pvid the vlan specified is to be considered a PVID at ingress. Any
530 untagged frames will be assigned to this VLAN.
531 untagged
534 the vlan specified is to be treated as untagged on egress.
535 self the vlan is configured on the specified physical device.
538 Required if the device is the bridge device.
539 master the vlan is configured on the software bridge (default).
542 bridge vlan delete - delete a vlan filter entry
545 This command removes an existing vlan filter entry.
546 The arguments are the same as with bridge vlan add. The pvid and
549 untagged flags are ignored.
550 bridge vlan show - list vlan configuration.
553 This command displays the current VLAN filter table.
554 With the -statistics option, the command displays per-vlan traffic sta‐
557 tistics.
558 bridge vlan tunnelshow - list vlan tunnel mapping.
561 This command displays the current vlan tunnel info mapping.
562
565 The bridge utility can monitor the state of devices and addresses con‐
566 tinuously. This option has a slightly different format. Namely, the
567 monitor command is the first in the command line and then the object
568 list follows:
569 bridge monitor [ all | OBJECT-LIST ]
571 OBJECT-LIST is the list of object types that we want to monitor. It
573 may contain link, fdb, and mdb. If no file argument is given, bridge
574 opens RTNETLINK, listens on it and dumps state changes in the format
575 described in previous sections.
576 If a file name is given, it does not listen on RTNETLINK, but opens the
579 file containing RTNETLINK messages saved in binary format and dumps
580 them.
581
584 This command uses facilities added in Linux 3.0.
585 Although the forwarding table is maintained on a per-bridge device
587 basis the bridge device is not part of the syntax. This is a limitation
588 of the underlying netlink neighbour message protocol. When displaying
589 the forwarding table, entries for all bridges are displayed.
590 Add/delete/modify commands determine the underlying bridge device based
591 on the bridge to which the corresponding ethernet device is attached.
592
596 ip(8)
597
599 Please direct bugreports and patches to: <netdev@vger.kernel.org>
600
603 Original Manpage by Stephen Hemminger
604iproute2 1 August 2012 BRIDGE(8)