1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
|
.. _bfd:
**********************************
Bidirectional Forwarding Detection
**********************************
:abbr:`BFD (Bidirectional Forwarding Detection)` stands for
Bidirectional Forwarding Detection and it is described and extended by
the following RFCs:
* :rfc:`5880`
* :rfc:`5881`
* :rfc:`5883`
Currently, there are two implementations of the BFD commands in FRR:
* :abbr:`PTM (Prescriptive Topology Manager)`: an external daemon which
implements BFD;
* ``bfdd``: a BFD implementation that is able to talk with remote peers;
This document will focus on the later implementation: *bfdd*.
.. _bfd-starting:
Starting BFD
============
*bfdd* default configuration file is :file:`bfdd.conf`. *bfdd* searches
the current directory first then |INSTALL_PREFIX_ETC|/bfdd.conf. All of
*bfdd*'s command must be configured in :file:`bfdd.conf`.
*bfdd* specific invocation options are described below. Common options
may also be specified (:ref:`common-invocation-options`).
.. program:: bfdd
.. option:: --bfdctl <unix-socket>
Set the BFD daemon control socket location. If using a non-default
socket location::
/usr/lib/frr/bfdd --bfdctl /tmp/bfdd.sock
The default UNIX socket location is:
#define BFDD_CONTROL_SOCKET "|INSTALL_PREFIX_STATE|/bfdd.sock"
This option overrides the location addition that the -N option provides
to the bfdd.sock
.. _bfd-commands:
BFDd Commands
=============
.. index:: bfd
.. clicmd:: bfd
Opens the BFD daemon configuration node.
.. index:: peer <A.B.C.D|X:X::X:X> [{multihop|local-address <A.B.C.D|X:X::X:X>|interface IFNAME|vrf NAME}]
.. clicmd:: peer <A.B.C.D|X:X::X:X> [{multihop|local-address <A.B.C.D|X:X::X:X>|interface IFNAME|vrf NAME}]
Creates and configures a new BFD peer to listen and talk to.
`multihop` tells the BFD daemon that we should expect packets with
TTL less than 254 (because it will take more than one hop) and to
listen on the multihop port (4784). When using multi-hop mode
`echo-mode` will not work (see :rfc:`5883` section 3).
`local-address` provides a local address that we should bind our
peer listener to and the address we should use to send the packets.
This option is mandatory for IPv6.
`interface` selects which interface we should use.
`vrf` selects which domain we want to use.
.. index:: no peer <A.B.C.D|X:X::X:X>$peer [{multihop|local-address <A.B.C.D|X:X::X:X>$local|interface IFNAME$ifname|vrf NAME$vrf_name}]
.. clicmd:: no peer <A.B.C.D|X:X::X:X>$peer [{multihop|local-address <A.B.C.D|X:X::X:X>$local|interface IFNAME$ifname|vrf NAME$vrf_name}]
Stops and removes the selected peer.
.. index:: profile WORD
.. clicmd:: profile WORD
Creates a peer profile that can be configured in multiple peers.
.. index:: no profile WORD
.. clicmd:: no profile WORD
Deletes a peer profile. Any peer using the profile will have their
configurations reset to the default values.
.. index:: show bfd [vrf NAME] peers [json]
.. clicmd:: show bfd [vrf NAME] peers [json]
Show all configured BFD peers information and current status.
.. index:: show bfd [vrf NAME$vrf_name] peer <WORD$label|<A.B.C.D|X:X::X:X>$peer [{multihop|local-address <A.B.C.D|X:X::X:X>$local|interface IFNAME$ifname}]> [json]
.. clicmd:: show bfd [vrf NAME$vrf_name] peer <WORD$label|<A.B.C.D|X:X::X:X>$peer [{multihop|local-address <A.B.C.D|X:X::X:X>$local|interface IFNAME$ifname}]> [json]
Show status for a specific BFD peer.
.. index:: show bfd [vrf NAME] peers brief [json]
.. clicmd:: show bfd [vrf NAME] peers brief [json]
Show all configured BFD peers information and current status in brief.
.. _bfd-peer-config:
Peer / Profile Configuration
----------------------------
BFD peers and profiles share the same BFD session configuration commands.
.. index:: detect-multiplier (2-255)
.. clicmd:: detect-multiplier (2-255)
Configures the detection multiplier to determine packet loss. The
remote transmission interval will be multiplied by this value to
determine the connection loss detection timer. The default value is
3.
Example: when the local system has `detect-multiplier 3` and the
remote system has `transmission interval 300`, the local system will
detect failures only after 900 milliseconds without receiving
packets.
.. index:: receive-interval (10-60000)
.. clicmd:: receive-interval (10-60000)
Configures the minimum interval that this system is capable of
receiving control packets. The default value is 300 milliseconds.
.. index:: transmit-interval (10-60000)
.. clicmd:: transmit-interval (10-60000)
The minimum transmission interval (less jitter) that this system
wants to use to send BFD control packets.
.. index:: echo-interval (10-60000)
.. clicmd:: echo-interval (10-60000)
Configures the minimal echo receive transmission interval that this
system is capable of handling.
.. index:: [no] echo-mode
.. clicmd:: [no] echo-mode
Enables or disables the echo transmission mode. This mode is disabled
by default.
It is recommended that the transmission interval of control packets
to be increased after enabling echo-mode to reduce bandwidth usage.
For example: `transmission-interval 2000`.
Echo mode is not supported on multi-hop setups (see :rfc:`5883`
section 3).
.. index:: [no] shutdown
.. clicmd:: [no] shutdown
Enables or disables the peer. When the peer is disabled an
'administrative down' message is sent to the remote peer.
BFD Peer Specific Commands
--------------------------
.. index:: label WORD
.. clicmd:: label WORD
Labels a peer with the provided word. This word can be referenced
later on other daemons to refer to a specific peer.
.. index:: profile BFDPROF
.. clicmd:: profile BFDPROF
Configure peer to use the profile configurations.
Notes:
- Profile configurations can be overriden on a peer basis by specifying
new parameters in peer configuration node.
- Non existing profiles can be configured and they will only be applied
once they start to exist.
- If the profile gets updated the new configuration will be applied to all
peers with the profile without interruptions.
.. _bfd-bgp-peer-config:
BGP BFD Configuration
---------------------
The following commands are available inside the BGP configuration node.
.. index:: neighbor <A.B.C.D|X:X::X:X|WORD> bfd
.. clicmd:: neighbor <A.B.C.D|X:X::X:X|WORD> bfd
Listen for BFD events registered on the same target as this BGP
neighbor. When BFD peer goes down it immediately asks BGP to shutdown
the connection with its neighbor and, when it goes back up, notify
BGP to try to connect to it.
.. index:: no neighbor <A.B.C.D|X:X::X:X|WORD> bfd
.. clicmd:: no neighbor <A.B.C.D|X:X::X:X|WORD> bfd
Removes any notification registration for this neighbor.
.. index:: neighbor <A.B.C.D|X:X::X:X|WORD> bfd check-control-plane-failure
.. clicmd:: neighbor <A.B.C.D|X:X::X:X|WORD> bfd check-control-plane-failure
Allow to write CBIT independence in BFD outgoing packets. Also allow to
read both C-BIT value of BFD and lookup BGP peer status. This command is
useful when a BFD down event is caught, while the BGP peer requested that
local BGP keeps the remote BGP entries as staled if such issue is detected.
This is the case when graceful restart is enabled, and it is wished to
ignore the BD event while waiting for the remote router to restart.
.. index:: no neighbor <A.B.C.D|X:X::X:X|WORD> bfd check-control-plane-failure
.. clicmd:: no neighbor <A.B.C.D|X:X::X:X|WORD> bfd check-control-plane-failure
Disallow to write CBIT independence in BFD outgoing packets. Also disallow
to ignore BFD down notification. This is the default behaviour.
.. index:: neighbor <A.B.C.D|X:X::X:X|WORD> bfd profile BFDPROF
.. clicmd:: neighbor <A.B.C.D|X:X::X:X|WORD> bfd profile BFDPROF
Same as command ``neighbor <A.B.C.D|X:X::X:X|WORD> bfd``, but applies the
BFD profile to the sessions it creates or that already exist.
.. index:: no neighbor <A.B.C.D|X:X::X:X|WORD> bfd profile BFDPROF
.. clicmd:: no neighbor <A.B.C.D|X:X::X:X|WORD> bfd profile BFDPROF
Removes the BFD profile configuration from peer session(s).
.. _bfd-ospf-peer-config:
OSPF BFD Configuration
----------------------
The following commands are available inside the interface configuration node.
.. index:: ip ospf bfd
.. clicmd:: ip ospf bfd
Listen for BFD events on peers created on the interface. Every time
a new neighbor is found a BFD peer is created to monitor the link
status for fast convergence.
.. index:: no ip ospf bfd
.. clicmd:: no ip ospf bfd
Removes any notification registration for this interface peers.
.. _bfd-ospf6-peer-config:
OSPF6 BFD Configuration
-----------------------
The following commands are available inside the interface configuration node.
.. index:: ipv6 ospf6 bfd
.. clicmd:: ipv6 ospf6 bfd
Listen for BFD events on peers created on the interface. Every time
a new neighbor is found a BFD peer is created to monitor the link
status for fast convergence.
.. index:: no ipv6 ospf6 bfd
.. clicmd:: no ipv6 ospf6 bfd
Removes any notification registration for this interface peers.
.. _bfd-pim-peer-config:
PIM BFD Configuration
---------------------
The following commands are available inside the interface configuration node.
.. index:: ip pim bfd
.. clicmd:: ip pim bfd
Listen for BFD events on peers created on the interface. Every time
a new neighbor is found a BFD peer is created to monitor the link
status for fast convergence.
.. index:: no ip pim bfd
.. clicmd:: no ip pim bfd
Removes any notification registration for this interface peers.
.. _bfd-configuration:
Configuration
=============
Before applying ``bfdd`` rules to integrated daemons (like BGPd), we must
create the corresponding peers inside the ``bfd`` configuration node.
Here is an example of BFD configuration:
::
bfd
peer 192.168.0.1
label home-peer
no shutdown
!
!
router bgp 65530
neighbor 192.168.0.1 remote-as 65531
neighbor 192.168.0.1 bfd
neighbor 192.168.0.2 remote-as 65530
neighbor 192.168.0.2 bfd
neighbor 192.168.0.3 remote-as 65532
neighbor 192.168.0.3 bfd
!
Peers can be identified by its address (use ``multihop`` when you need
to specify a multi hop peer) or can be specified manually by a label.
Here are the available peer configurations:
::
bfd
! Configure a fast profile
profile fast
receive-interval 150
transmit-interval 150
!
! Configure peer with fast profile
peer 192.168.0.6
profile fast
no shutdown
!
! Configure peer with fast profile and override receive speed.
peer 192.168.0.7
profile fast
receive-interval 500
no shutdown
!
! configure a peer on an specific interface
peer 192.168.0.1 interface eth0
no shutdown
!
! configure a multihop peer
peer 192.168.0.2 multihop local-address 192.168.0.3
shutdown
!
! configure a peer in a different vrf
peer 192.168.0.3 vrf foo
shutdown
!
! configure a peer with every option possible
peer 192.168.0.4
label peer-label
detect-multiplier 50
receive-interval 60000
transmit-interval 3000
shutdown
!
! configure a peer on an interface from a separate vrf
peer 192.168.0.5 interface eth1 vrf vrf2
no shutdown
!
! remove a peer
no peer 192.168.0.3 vrf foo
.. _bfd-status:
Status
======
You can inspect the current BFD peer status with the following commands:
::
frr# show bfd peers
BFD Peers:
peer 192.168.0.1
ID: 1
Remote ID: 1
Status: up
Uptime: 1 minute(s), 51 second(s)
Diagnostics: ok
Remote diagnostics: ok
Peer Type: dynamic
Local timers:
Detect-multiplier: 3
Receive interval: 300ms
Transmission interval: 300ms
Echo transmission interval: disabled
Remote timers:
Detect-multiplier: 3
Receive interval: 300ms
Transmission interval: 300ms
Echo transmission interval: 50ms
peer 192.168.1.1
label: router3-peer
ID: 2
Remote ID: 2
Status: up
Uptime: 1 minute(s), 53 second(s)
Diagnostics: ok
Remote diagnostics: ok
Peer Type: configured
Local timers:
Detect-multiplier: 3
Receive interval: 300ms
Transmission interval: 300ms
Echo transmission interval: disabled
Remote timers:
Detect-multiplier: 3
Receive interval: 300ms
Transmission interval: 300ms
Echo transmission interval: 50ms
frr# show bfd peer 192.168.1.1
BFD Peer:
peer 192.168.1.1
label: router3-peer
ID: 2
Remote ID: 2
Status: up
Uptime: 3 minute(s), 4 second(s)
Diagnostics: ok
Remote diagnostics: ok
Peer Type: dynamic
Local timers:
Detect-multiplier: 3
Receive interval: 300ms
Transmission interval: 300ms
Echo transmission interval: disabled
Remote timers:
Detect-multiplier: 3
Receive interval: 300ms
Transmission interval: 300ms
Echo transmission interval: 50ms
frr# show bfd peer 192.168.0.1 json
{"multihop":false,"peer":"192.168.0.1","id":1,"remote-id":1,"status":"up","uptime":161,"diagnostic":"ok","remote-diagnostic":"ok","receive-interval":300,"transmit-interval":300,"echo-interval":50,"detect-multiplier":3,"remote-receive-interval":300,"remote-transmit-interval":300,"remote-echo-interval":50,"remote-detect-multiplier":3,"peer-type":"dynamic"}
You can inspect the current BFD peer status in brief with the following commands:
::
frr# show bfd peers brief
Session count: 1
SessionId LocalAddress PeerAddress Status
========= ============ =========== ======
1 192.168.0.1 192.168.0.2 up
You can also inspect peer session counters with the following commands:
::
frr# show bfd peers counters
BFD Peers:
peer 192.168.2.1 interface r2-eth2
Control packet input: 28 packets
Control packet output: 28 packets
Echo packet input: 0 packets
Echo packet output: 0 packets
Session up events: 1
Session down events: 0
Zebra notifications: 2
peer 192.168.0.1
Control packet input: 54 packets
Control packet output: 103 packets
Echo packet input: 965 packets
Echo packet output: 966 packets
Session up events: 1
Session down events: 0
Zebra notifications: 4
frr# show bfd peer 192.168.0.1 counters
peer 192.168.0.1
Control packet input: 126 packets
Control packet output: 247 packets
Echo packet input: 2409 packets
Echo packet output: 2410 packets
Session up events: 1
Session down events: 0
Zebra notifications: 4
frr# show bfd peer 192.168.0.1 counters json
{"multihop":false,"peer":"192.168.0.1","control-packet-input":348,"control-packet-output":685,"echo-packet-input":6815,"echo-packet-output":6816,"session-up":1,"session-down":0,"zebra-notifications":4}
You can also clear packet counters per session with the following commands, only the packet counters will be reset:
::
frr# clear bfd peers counters
frr# show bfd peers counters
BFD Peers:
peer 192.168.2.1 interface r2-eth2
Control packet input: 0 packets
Control packet output: 0 packets
Echo packet input: 0 packets
Echo packet output: 0 packets
Session up events: 1
Session down events: 0
Zebra notifications: 2
peer 192.168.0.1
Control packet input: 0 packets
Control packet output: 0 packets
Echo packet input: 0 packets
Echo packet output: 0 packets
Session up events: 1
Session down events: 0
Zebra notifications: 4
Debugging
=========
By default only informational, warning and errors messages are going to be
displayed. If you want to get debug messages and other diagnostics then make
sure you have `debugging` level enabled:
::
config
log file /var/log/frr/frr.log debugging
log syslog debugging
You may also fine tune the debug messages by selecting one or more of the
debug levels:
.. index:: [no] debug bfd network
.. clicmd:: [no] debug bfd network
Toggle network events: show messages about socket failures and unexpected
BFD messages that may not belong to registered peers.
.. index:: [no] debug bfd peer
.. clicmd:: [no] debug bfd peer
Toggle peer event log messages: show messages about peer creation/removal
and state changes.
.. index:: [no] debug bfd zebra
.. clicmd:: [no] debug bfd zebra
Toggle zebra message events: show messages about interfaces, local
addresses, VRF and daemon peer registrations.
|
