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 | -j[son] }
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 } ] [ self ] [
23 master ]
24 bridge link [ show ] [ dev DEV ]
26 bridge fdb { add | append | del | replace } LLADDR dev DEV { local |
28 static | dynamic } [ self ] [ master ] [ router ] [ use ] [ dst
29 IPADDR ] [ vni VNI ] [ port PORT ] [ via DEVICE ]
30 bridge fdb [ show ] [ dev DEV ] [ br BRDEV ] [ brport DEV ] [ vlan VID
32 ] [ state STATE ]
33 bridge mdb { add | del } dev DEV port PORT grp GROUP [ permanent | temp
35 ] [ vid VID ]
36 bridge mdb show [ dev DEV ]
38 bridge vlan { add | del } dev DEV vid VID [ pvid ] [ untagged ] [ self
40 ] [ master ]
41 bridge vlan [ show ] [ dev DEV ]
43 bridge monitor [ all | neigh | link | mdb ]
45
48 -V, -Version
49 print the version of the bridge utility and exit.
50 -s, -stats, -statistics
53 output more information. If this option is given multiple times,
54 the amount of information increases. As a rule, the information
55 is statistics or some time values.
56 -d, -details
59 print detailed information about MDB router ports.
60 -n, -net, -netns <NETNS>
63 switches bridge to the specified network namespace NETNS. Actu‐
64 ally it just simplifies executing of:
65 ip netns exec NETNS bridge [ OPTIONS ] OBJECT { COMMAND | help }
67 to
69 bridge -n[etns] NETNS [ OPTIONS ] OBJECT { COMMAND | help }
71 -b, -batch <FILENAME>
74 Read commands from provided file or standard input and invoke
75 them. First failure will cause termination of bridge command.
76 -force Don't terminate bridge command on errors in batch mode. If
79 there were any errors during execution of the commands, the
80 application return code will be non zero.
81 -json Display results in JSON format. Currently available for vlan and
84 fdb.
85
88 OBJECT
89 link - Bridge port.
90 fdb - Forwarding Database entry.
93 mdb - Multicast group database entry.
96 vlan - VLAN filter list.
99 COMMAND
102 Specifies the action to perform on the object. The set of possible
103 actions depends on the object type. As a rule, it is possible to add,
104 delete and show (or list ) objects, but some objects do not allow all
105 of these operations or have some additional commands. The help command
106 is available for all objects. It prints out a list of available com‐
107 mands and argument syntax conventions.
108 If no command is given, some default command is assumed. Usually it is
110 list or, if the objects of this class cannot be listed, help.
111
114 link objects correspond to the port devices of the bridge.
115 The corresponding commands set and display port status and bridge spe‐
118 cific attributes.
119 bridge link set - set bridge specific attributes on a port
122 dev NAME
123 interface name of the bridge port
124 cost COST
127 the STP path cost of the specified port.
128 priority PRIO
131 the STP port priority. The priority value is an unsigned 8-bit
132 quantity (number between 0 and 255). This metric is used in the
133 designated port an droot port selectio algorithms.
134 state STATE
137 the operation state of the port. This is primarily used by user
138 space STP/RSTP implementation. One may enter a lowercased port
139 state name, or one of the numbers below. Negative inputs are
140 ignored, and unrecognized names return an error.
141 0 - port is DISABLED. Make this port completely inactive.
143 1 - STP LISTENING state. Only valid if STP is enabled on the
146 bridge. In this state the port listens for STP BPDUs and drops
147 all other traffic frames.
148 2 - STP LEARNING state. Only valid if STP is enabled on the
151 bridge. In this state the port will accept traffic only for the
152 purpose of updating MAC address tables.
153 3 - STP FORWARDING state. Port is fully active.
156 4 - STP BLOCKING state. Only valid if STP is enabled on the
159 bridge. This state is used during the STP election process. In
160 this state, port will only process STP BPDUs.
161 guard on or guard off
165 Controls whether STP BPDUs will be processed by the bridge port.
166 By default, the flag is turned off allowed BPDU processing.
167 Turning this flag on will cause the port to stop processing STP
168 BPDUs.
169 hairpin on or hairpin off
172 Controls whether traffic may be send back out of the port on
173 which it was received. By default, this flag is turned off and
174 the bridge will not forward traffic back out of the receiving
175 port.
176 fastleave on or fastleave off
179 This flag allows the bridge to immediately stop multicast traf‐
180 fic on a port that receives IGMP Leave message. It is only used
181 with IGMP snooping is enabled on the bridge. By default the flag
182 is off.
183 root_block on or root_block off
186 Controls whether a given port is allowed to become root port or
187 not. Only used when STP is enabled on the bridge. By default the
188 flag is off.
189 learning on or learning off
192 Controls whether a given port will learn MAC addresses from
193 received traffic or not. If learning if off, the bridge will end
194 up flooding any traffic for which it has no FDB entry. By
195 default this flag is on.
196 learning_sync on or learning_sync off
199 Controls whether a given port will sync MAC addresses learned on
200 device port to bridge FDB.
201 flooding on or flooding off
204 Controls whether a given port will flood unicast traffic for
205 which there is no FDB entry. By default this flag is on.
206 hwmode Some network interface cards support HW bridge functionality and
209 they may be configured in different modes. Currently support
210 modes are:
211 vepa - Data sent between HW ports is sent on the wire to the
213 external switch.
214 veb - bridging happens in hardware.
216 mcast_flood on or mcast_flood off
219 Controls whether a given port will be flooded with multicast
220 traffic for which there is no MDB entry. By default this flag is
221 on.
222 self link setting is configured on specified physical device
225 master link setting is configured on the software bridge (default)
228 -t, -timestamp
231 display current time when using monitor option.
232 bridge link show - list bridge port configuration.
235 This command displays the current bridge port configuration and flags.
236
239 fdb objects contain known Ethernet addresses on a link.
240 The corresponding commands display fdb entries, add new entries, append
243 entries, and delete old ones.
244 bridge fdb add - add a new fdb entry
247 This command creates a new fdb entry.
248 LLADDR the Ethernet MAC address.
251 dev DEV
254 the interface to which this address is associated.
255 local - is a local permanent fdb entry
257 static - is a static (no arp) fdb entry
260 dynamic - is a dynamic reachable age-able fdb entry
263 self - the address is associated with the port drivers fdb. Usu‐
266 ally hardware.
267 master - the address is associated with master devices fdb. Usu‐
270 ally software (default).
271 router - the destination address is associated with a router.
274 Valid if the referenced device is a VXLAN type device and has
275 route shortcircuit enabled.
276 use - the address is in use. User space can use this option to
279 indicate to the kernel that the fdb entry is in use.
280 The next command line parameters apply only when the specified device
283 DEV is of type VXLAN.
284 dst IPADDR
286 the IP address of the destination VXLAN tunnel endpoint where
287 the Ethernet MAC ADDRESS resides.
288 vni VNI
291 the VXLAN VNI Network Identifier (or VXLAN Segment ID) to use to
292 connect to the remote VXLAN tunnel endpoint. If omitted the
293 value specified at vxlan device creation will be used.
294 port PORT
297 the UDP destination PORT number to use to connect to the remote
298 VXLAN tunnel endpoint. If omitted the default value is used.
299 via DEVICE
302 device name of the outgoing interface for the VXLAN device
303 driver to reach the remote VXLAN tunnel endpoint.
304 bridge fdb append - append a forwarding database entry
307 This command adds a new fdb entry with an already known LLADDR. Valid
308 only for multicast link layer addresses. The command adds support for
309 broadcast and multicast Ethernet MAC addresses. The Ethernet MAC
310 address is added multiple times into the forwarding database and the
311 vxlan device driver sends a copy of the data packet to each entry
312 found.
313 The arguments are the same as with bridge fdb add.
316 bridge fdb delete - delete a forwarding database entry
319 This command removes an existing fdb entry.
320 The arguments are the same as with bridge fdb add.
323 bridge fdb replace - replace a forwarding database entry
326 If no matching entry is found, a new one will be created instead.
327 The arguments are the same as with bridge fdb add.
330 bridge fdb show - list forwarding entries.
333 This command displays the current forwarding table.
334 With the -statistics option, the command becomes verbose. It prints out
337 the last updated and last used time for each entry.
338
341 mdb objects contain known IP multicast group addresses on a link.
342 The corresponding commands display mdb entries, add new entries, and
345 delete old ones.
346 bridge mdb add - add a new multicast group database entry
349 This command creates a new mdb entry.
350 dev DEV
353 the interface where this group address is associated.
354 port PORT
357 the port whose link is known to have members of this multicast
358 group.
359 grp GROUP
362 the IP multicast group address whose members reside on the link
363 connected to the port.
364 permanent - the mdb entry is permanent
366 temp - the mdb entry is temporary (default)
369 vid VID
373 the VLAN ID which is known to have members of this multicast
374 group.
375 bridge mdb delete - delete a multicast group database entry
378 This command removes an existing mdb entry.
379 The arguments are the same as with bridge mdb add.
382 bridge mdb show - list multicast group database entries
385 This command displays the current multicast group membership table. The
386 table is populated by IGMP and MLD snooping in the bridge driver auto‐
387 matically. It can be altered by bridge mdb add and bridge mdb del com‐
388 mands manually too.
389 dev DEV
392 the interface only whose entries should be listed. Default is to
393 list all bridge interfaces.
394 With the -details option, the command becomes verbose. It prints out
397 the ports known to have a connected router.
398 With the -statistics option, the command displays timer values for mdb
401 and router port entries.
402
405 vlan objects contain known VLAN IDs for a link.
406 The corresponding commands display vlan filter entries, add new
409 entries, and delete old ones.
410 bridge vlan add - add a new vlan filter entry
413 This command creates a new vlan filter entry.
414 dev NAME
417 the interface with which this vlan is associated.
418 vid VID
421 the VLAN ID that identifies the vlan.
422 pvid the vlan specified is to be considered a PVID at ingress. Any
425 untagged frames will be assigned to this VLAN.
426 untagged
429 the vlan specified is to be treated as untagged on egress.
430 self the vlan is configured on the specified physical device.
433 Required if the device is the bridge device.
434 master the vlan is configured on the software bridge (default).
437 bridge vlan delete - delete a vlan filter entry
440 This command removes an existing vlan filter entry.
441 The arguments are the same as with bridge vlan add. The pvid and
444 untagged flags are ignored.
445 bridge vlan show - list vlan configuration.
448 This command displays the current VLAN filter table.
449 With the -statistics option, the command displays per-vlan traffic sta‐
452 tistics.
453
456 The bridge utility can monitor the state of devices and addresses con‐
457 tinuously. This option has a slightly different format. Namely, the
458 monitor command is the first in the command line and then the object
459 list follows:
460 bridge monitor [ all | OBJECT-LIST ]
462 OBJECT-LIST is the list of object types that we want to monitor. It
464 may contain link, fdb, and mdb. If no file argument is given, bridge
465 opens RTNETLINK, listens on it and dumps state changes in the format
466 described in previous sections.
467 If a file name is given, it does not listen on RTNETLINK, but opens the
470 file containing RTNETLINK messages saved in binary format and dumps
471 them.
472
475 This command uses facilities added in Linux 3.0.
476 Although the forwarding table is maintained on a per-bridge device
478 basis the bridge device is not part of the syntax. This is a limitation
479 of the underlying netlink neighbour message protocol. When displaying
480 the forwarding table, entries for all bridges are displayed.
481 Add/delete/modify commands determine the underlying bridge device based
482 on the bridge to which the corresponding ethernet device is attached.
483
487 ip(8)
488
490 Please direct bugreports and patches to: <netdev@vger.kernel.org>
491
494 Original Manpage by Stephen Hemminger
495iproute2 1 August 2012 BRIDGE(8)