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 SRC_VNI ] [
32 vni VNI ] [ port PORT ] [ via DEVICE ]
33 bridge fdb [ show ] [ dev DEV ] [ br BRDEV ] [ brport DEV ] [ vlan VID
35 ] [ state STATE ]
36 bridge mdb { add | del } dev DEV port PORT grp GROUP [ permanent | temp
38 ] [ vid VID ]
39 bridge mdb show [ dev DEV ]
41 bridge vlan { add | del } dev DEV vid VID [ tunnel_info TUNNEL_ID ] [
43 pvid ] [ untagged ] [ self ] [ master ]
44 bridge vlan [ show | tunnelshow ] [ dev DEV ]
46 bridge monitor [ all | neigh | link | mdb ]
48
51 -V, -Version
52 print the version of the bridge utility and exit.
53 -s, -stats, -statistics
56 output more information. If this option is given multiple times,
57 the amount of information increases. As a rule, the information
58 is statistics or some time values.
59 -d, -details
62 print detailed information about MDB router ports.
63 -n, -net, -netns <NETNS>
66 switches bridge to the specified network namespace NETNS. Actu‐
67 ally it just simplifies executing of:
68 ip netns exec NETNS bridge [ OPTIONS ] OBJECT { COMMAND | help }
70 to
72 bridge -n[etns] NETNS [ OPTIONS ] OBJECT { COMMAND | help }
74 -b, -batch <FILENAME>
77 Read commands from provided file or standard input and invoke
78 them. First failure will cause termination of bridge command.
79 -force Don't terminate bridge command on errors in batch mode. If
82 there were any errors during execution of the commands, the
83 application return code will be non zero.
84 -c[color][={always|auto|never}
87 Configure color output. If parameter is omitted or always, color
88 output is enabled regardless of stdout state. If parameter is
89 auto, stdout is checked to be a terminal before enabling color
90 output. If parameter is never, color output is disabled. If
91 specified multiple times, the last one takes precedence. This
92 flag is ignored if -json is also given.
93 -j, -json
96 Output results in JavaScript Object Notation (JSON).
97 -p, -pretty
100 When combined with -j generate a pretty JSON output.
101 -o, -oneline
104 output each record on a single line, replacing line feeds with
105 the '\' character. This is convenient when you want to count
106 records with wc(1) or to grep(1) the output.
107
111 OBJECT
112 link - Bridge port.
113 fdb - Forwarding Database entry.
116 mdb - Multicast group database entry.
119 vlan - VLAN filter list.
122 COMMAND
125 Specifies the action to perform on the object. The set of possible
126 actions depends on the object type. As a rule, it is possible to add,
127 delete and show (or list ) objects, but some objects do not allow all
128 of these operations or have some additional commands. The help command
129 is available for all objects. It prints out a list of available com‐
130 mands and argument syntax conventions.
131 If no command is given, some default command is assumed. Usually it is
133 list or, if the objects of this class cannot be listed, help.
134
137 link objects correspond to the port devices of the bridge.
138 The corresponding commands set and display port status and bridge spe‐
141 cific attributes.
142 bridge link set - set bridge specific attributes on a port
145 dev NAME
146 interface name of the bridge port
147 cost COST
150 the STP path cost of the specified port.
151 priority PRIO
154 the STP port priority. The priority value is an unsigned 8-bit
155 quantity (number between 0 and 255). This metric is used in the
156 designated port an droot port selectio algorithms.
157 state STATE
160 the operation state of the port. This is primarily used by user
161 space STP/RSTP implementation. One may enter a lowercased port
162 state name, or one of the numbers below. Negative inputs are
163 ignored, and unrecognized names return an error.
164 0 - port is DISABLED. Make this port completely inactive.
166 1 - STP LISTENING state. Only valid if STP is enabled on the
169 bridge. In this state the port listens for STP BPDUs and drops
170 all other traffic frames.
171 2 - STP LEARNING state. Only valid if STP is enabled on the
174 bridge. In this state the port will accept traffic only for the
175 purpose of updating MAC address tables.
176 3 - STP FORWARDING state. Port is fully active.
179 4 - STP BLOCKING state. Only valid if STP is enabled on the
182 bridge. This state is used during the STP election process. In
183 this state, port will only process STP BPDUs.
184 guard on or guard off
188 Controls whether STP BPDUs will be processed by the bridge port.
189 By default, the flag is turned off allowed BPDU processing.
190 Turning this flag on will cause the port to stop processing STP
191 BPDUs.
192 hairpin on or hairpin off
195 Controls whether traffic may be send back out of the port on
196 which it was received. By default, this flag is turned off and
197 the bridge will not forward traffic back out of the receiving
198 port.
199 fastleave on or fastleave off
202 This flag allows the bridge to immediately stop multicast traf‐
203 fic on a port that receives IGMP Leave message. It is only used
204 with IGMP snooping is enabled on the bridge. By default the flag
205 is off.
206 root_block on or root_block off
209 Controls whether a given port is allowed to become root port or
210 not. Only used when STP is enabled on the bridge. By default the
211 flag is off.
212 learning on or learning off
215 Controls whether a given port will learn MAC addresses from
216 received traffic or not. If learning if off, the bridge will end
217 up flooding any traffic for which it has no FDB entry. By
218 default this flag is on.
219 learning_sync on or learning_sync off
222 Controls whether a given port will sync MAC addresses learned on
223 device port to bridge FDB.
224 flood on or flood off
227 Controls whether a given port will flood unicast traffic for
228 which there is no FDB entry. By default this flag is on.
229 hwmode Some network interface cards support HW bridge functionality and
232 they may be configured in different modes. Currently support
233 modes are:
234 vepa - Data sent between HW ports is sent on the wire to the
236 external switch.
237 veb - bridging happens in hardware.
239 mcast_flood on or mcast_flood off
242 Controls whether a given port will flood multicast traffic for
243 which there is no MDB entry. By default this flag is on.
244 mcast_to_unicast on or mcast_to_unicast off
247 Controls whether a given port will replicate packets using uni‐
248 cast instead of multicast. By default this flag is off.
249 neigh_suppress on or neigh_suppress off
252 Controls whether neigh discovery (arp and nd) proxy and suppres‐
253 sion is enabled on the port. By default this flag is off.
254 vlan_tunnel on or vlan_tunnel off
257 Controls whether vlan to tunnel mapping is enabled on the port.
258 By default this flag is off.
259 isolated on or isolated off
262 Controls whether a given port will be isolated, which means it
263 will be able to communicate with non-isolated ports only. By
264 default this flag is off.
265 backup_port DEVICE
268 If the port loses carrier all traffic will be redirected to the
269 configured backup port
270 nobackup_port
273 Removes the currently configured backup port
274 self link setting is configured on specified physical device
277 master link setting is configured on the software bridge (default)
280 -t, -timestamp
283 display current time when using monitor option.
284 bridge link show - list bridge port configuration.
287 This command displays the current bridge port configuration and flags.
288
291 fdb objects contain known Ethernet addresses on a link.
292 The corresponding commands display fdb entries, add new entries, append
295 entries, and delete old ones.
296 bridge fdb add - add a new fdb entry
299 This command creates a new fdb entry.
300 LLADDR the Ethernet MAC address.
303 dev DEV
306 the interface to which this address is associated.
307 local - is a local permanent fdb entry
309 static - is a static (no arp) fdb entry
312 dynamic - is a dynamic reachable age-able fdb entry
315 self - the address is associated with the port drivers fdb. Usu‐
318 ally hardware.
319 master - the address is associated with master devices fdb. Usu‐
322 ally software (default).
323 router - the destination address is associated with a router.
326 Valid if the referenced device is a VXLAN type device and has
327 route shortcircuit enabled.
328 use - the address is in use. User space can use this option to
331 indicate to the kernel that the fdb entry is in use.
332 extern_learn - this entry was learned externally. This option
335 can be used to indicate to the kernel that an entry was hardware
336 or user-space controller learnt dynamic entry. Kernel will not
337 age such an entry.
338 sticky - this entry will not change its port due to learning.
341 The next command line parameters apply only when the specified device
344 DEV is of type VXLAN.
345 dst IPADDR
347 the IP address of the destination VXLAN tunnel endpoint where
348 the Ethernet MAC ADDRESS resides.
349 src_vni SRC VNI
352 the src VNI Network Identifier (or VXLAN Segment ID) this entry
353 belongs to. Used only when the vxlan device is in external or
354 collect metadata mode. If omitted the value specified at vxlan
355 device creation will be used.
356 vni VNI
359 the VXLAN VNI Network Identifier (or VXLAN Segment ID) to use to
360 connect to the remote VXLAN tunnel endpoint. If omitted the
361 value specified at vxlan device creation will be used.
362 port PORT
365 the UDP destination PORT number to use to connect to the remote
366 VXLAN tunnel endpoint. If omitted the default value is used.
367 via DEVICE
370 device name of the outgoing interface for the VXLAN device
371 driver to reach the remote VXLAN tunnel endpoint.
372 bridge fdb append - append a forwarding database entry
375 This command adds a new fdb entry with an already known LLADDR. Valid
376 only for multicast link layer addresses. The command adds support for
377 broadcast and multicast Ethernet MAC addresses. The Ethernet MAC
378 address is added multiple times into the forwarding database and the
379 vxlan device driver sends a copy of the data packet to each entry
380 found.
381 The arguments are the same as with bridge fdb add.
384 bridge fdb delete - delete a forwarding database entry
387 This command removes an existing fdb entry.
388 The arguments are the same as with bridge fdb add.
391 bridge fdb replace - replace a forwarding database entry
394 If no matching entry is found, a new one will be created instead.
395 The arguments are the same as with bridge fdb add.
398 bridge fdb show - list forwarding entries.
401 This command displays the current forwarding table.
402 With the -statistics option, the command becomes verbose. It prints out
405 the last updated and last used time for each entry.
406
409 mdb objects contain known IP multicast group addresses on a link.
410 The corresponding commands display mdb entries, add new entries, and
413 delete old ones.
414 bridge mdb add - add a new multicast group database entry
417 This command creates a new mdb entry.
418 dev DEV
421 the interface where this group address is associated.
422 port PORT
425 the port whose link is known to have members of this multicast
426 group.
427 grp GROUP
430 the IP multicast group address whose members reside on the link
431 connected to the port.
432 permanent - the mdb entry is permanent
434 temp - the mdb entry is temporary (default)
437 vid VID
441 the VLAN ID which is known to have members of this multicast
442 group.
443 bridge mdb delete - delete a multicast group database entry
446 This command removes an existing mdb entry.
447 The arguments are the same as with bridge mdb add.
450 bridge mdb show - list multicast group database entries
453 This command displays the current multicast group membership table. The
454 table is populated by IGMP and MLD snooping in the bridge driver auto‐
455 matically. It can be altered by bridge mdb add and bridge mdb del com‐
456 mands manually too.
457 dev DEV
460 the interface only whose entries should be listed. Default is to
461 list all bridge interfaces.
462 With the -details option, the command becomes verbose. It prints out
465 the ports known to have a connected router.
466 With the -statistics option, the command displays timer values for mdb
469 and router port entries.
470
473 vlan objects contain known VLAN IDs for a link.
474 The corresponding commands display vlan filter entries, add new
477 entries, and delete old ones.
478 bridge vlan add - add a new vlan filter entry
481 This command creates a new vlan filter entry.
482 dev NAME
485 the interface with which this vlan is associated.
486 vid VID
489 the VLAN ID that identifies the vlan.
490 tunnel_info TUNNEL_ID
493 the TUNNEL ID that maps to this vlan. The tunnel id is set in
494 dst_metadata for every packet that belongs to this vlan (appli‐
495 cable to bridge ports with vlan_tunnel flag set).
496 pvid the vlan specified is to be considered a PVID at ingress. Any
499 untagged frames will be assigned to this VLAN.
500 untagged
503 the vlan specified is to be treated as untagged on egress.
504 self the vlan is configured on the specified physical device.
507 Required if the device is the bridge device.
508 master the vlan is configured on the software bridge (default).
511 bridge vlan delete - delete a vlan filter entry
514 This command removes an existing vlan filter entry.
515 The arguments are the same as with bridge vlan add. The pvid and
518 untagged flags are ignored.
519 bridge vlan show - list vlan configuration.
522 This command displays the current VLAN filter table.
523 With the -statistics option, the command displays per-vlan traffic sta‐
526 tistics.
527 bridge vlan tunnelshow - list vlan tunnel mapping.
530 This command displays the current vlan tunnel info mapping.
531
534 The bridge utility can monitor the state of devices and addresses con‐
535 tinuously. This option has a slightly different format. Namely, the
536 monitor command is the first in the command line and then the object
537 list follows:
538 bridge monitor [ all | OBJECT-LIST ]
540 OBJECT-LIST is the list of object types that we want to monitor. It
542 may contain link, fdb, and mdb. If no file argument is given, bridge
543 opens RTNETLINK, listens on it and dumps state changes in the format
544 described in previous sections.
545 If a file name is given, it does not listen on RTNETLINK, but opens the
548 file containing RTNETLINK messages saved in binary format and dumps
549 them.
550
553 This command uses facilities added in Linux 3.0.
554 Although the forwarding table is maintained on a per-bridge device
556 basis the bridge device is not part of the syntax. This is a limitation
557 of the underlying netlink neighbour message protocol. When displaying
558 the forwarding table, entries for all bridges are displayed.
559 Add/delete/modify commands determine the underlying bridge device based
560 on the bridge to which the corresponding ethernet device is attached.
561
565 ip(8)
566
568 Please direct bugreports and patches to: <netdev@vger.kernel.org>
569
572 Original Manpage by Stephen Hemminger
573iproute2 1 August 2012 BRIDGE(8)