Home » Dell Manuals » Hubs & Switches » Dell PowerSwitch S4128F-ON » Manual Viewer

Dell PowerSwitch S4128F-ON EMC SmartFabric OS10 User Guide Release 10.5.1 - Page 448

Far-end failure detection

View all Dell PowerSwitch S4128F-ON manuals

Add to My Manuals
Save this manual to your list of manuals

Page 448 highlights

Far-end failure detection Far-End Failure Detection (FEFD) is a protocol that detects remote data link errors in a network. FEFD uses a link layer echo protocol to detect and signal far-end failures over Ethernet and optical links. When you enable FEFD, switches periodically exchange FEFD echo frames to identify link failures. If the local switch does not receive an echo from its peer for the time interval of three times the configured FEFD message interval, the local switch assumes that the peer link is down. The default interval for FEFD message interval is 15 seconds. For example, with the default configuration, if the local switch does not receive an echo message for 45 seconds from its peer, it brings the peer link down. FEFD helps detect far-end failure when the following problems occur: ● Only one side receives packets although the physical layer (L1) of the link is up on both sides. ● Transceivers are not connected to the correct ports. FEFD states FEFD comprises the following four states: ● Idle-FEFD is disabled. ● Unknown-Shown when FEFD is enabled and changes to bi-directional after successful handshake with the peer. Also shown if the peer goes down in normal mode. ● bi-directional-Interface is up, connected, and receiving echoes of its neighbor. ● err-disabled-Only found when FEFD mode is aggressive and when the interface has not received three echoes of its neighbor. To reset an interface in this state, use the fefd reset command. FEFD modes FEFD operates in two modes-Normal mode and aggressive mode. ● Normal mode-When you enable Normal mode on an interface and a far-end failure is detected, no intervention is required to reset the interface to bring it back to an FEFD operational state. ● Aggressive mode-When you enable Aggressive mode on an interface in the same state, you must manually reset the interface. The following events explain how FEFD state transition occurs: ● When you enable FEFD on an interface a link transitions from idle state to unknown state. 448 Layer 2

Section	Page
Dell EMC SmartFabric OS10 User Guide Release 10.5.1	3
About this guide	27
Conventions	27
Related Documents	27
Documentation Feedback	27
Change history	28
Getting Started with Dell EMC SmartFabric OS10	30
Switch with factory-installed OS10	31
Log in	31
Check OS10 version	32
OS10 upgrade	32
Download OS10 image for upgrade	33
Install OS10 upgrade	33
Install firmware upgrade	35
Upgrade commands	35
boot system	35
image cancel	36
image copy	36
image download	36
image install	37
show boot	38
show image firmware	38
show image status	39
show version	40
Check OS10 license	40
Re-install license	41
Switch without OS installed	41
Uninstall existing OS	42
Download OS10 image	42
Installation using ONIE	43
Automatic installation	44
Manual installation	45
Log in	46
Install OS10 license	46
Downgrade to Release 10.5.0.0 or earlier releases	49
Roll back from 10.5.1.0 or later release to 10.5.0.0 or earlier release	50
Switch deployment options	50
Manual CLI configuration	51
ZTD-automated switch deployment	51
Ansible-automated switch provisioning	51
Feature limitation on the Z9100-ON and S5200-ON series switches	51
Feature limitations on Z9332F-ON switch	51
Remote access	51
Configure Management IP address	52
Configure Management route	52
Configure username and password	53
CLI Basics	54
CONFIGURATION mode	55
Check device status	56
Related Videos	57
Command help	57
Candidate configuration	58
Copy running configuration	61
Restore startup configuration	62
Reload system image	63
Filter show commands	63
Common OS10 commands	64
boot	64
commit	64
configure	64
copy	65
delete	66
dir	67
discard	68
do	68
end	69
exit	69
hostname	69
license	70
lock	70
management route	71
move	71
no	72
ping	72
ping6	74
reload	75
show boot	76
show candidate-configuration	76
show environment	79
show inventory	79
show ip management-route	80
show ipv6 management-route	80
show license status	81
show running-configuration	81
show startup-configuration	84
show system	85
show version	87
start	87
system	87
system-cli disable	88
system-user linuxadmin disable	88
system identifier	89
terminal	89
traceroute	89
unlock	90
username password role	91
write	92
Advanced CLI tasks	93
Command alias	93
Multi-line alias	94
alias	96
alias (multi-line)	97
default (alias)	98
description (alias)	98
line (alias)	98
show alias	99
Batch mode	100
batch	100
Linux shell commands	101
Using OS9 commands	103
feature config-os9-style	103
Dell EMC SmartFabric OS10 zero-touch deployment	104
ZTD DHCP server configuration	106
ZTD provisioning script	106
ZTD CLI batch file	107
Post-ZTD script	108
ZTD commands	108
reload ztd	108
show ztd-status	108
ztd cancel	109
Dell EMC SmartFabric OS10 provisioning	110
Using Ansible	110
Example: Configure an OS10 switch using Ansible	111
System management	114
System banners	114
Login banner	114
Message of the day banner	115
System banner commands	115
banner login	115
banner motd	116
User session management	116
User session management commands	117
exec-timeout	117
kill-session	117
show sessions	118
Telnet server	118
Telnet commands	119
ip telnet server enable	119
ip telnet server vrf	119
Simple Network Management Protocol	119
SNMP security models and levels	120
MIBs	120
SNMPv3	121
SNMP engine ID	122
SNMP groups and users	122
SNMP views	122
Configure SNMP	122
Configure SNMP engine ID	122
Configure SNMP views	123
Configure SNMP groups	123
Configure SNMP users	124
Generate SNMPv3 localized keys	125
Configure SNMP traps	125
Configure SNMP informs	126
SNMP commands	126
show snmp community	126
show snmp engineID	127
show snmp group	127
show snmp user	127
show snmp view	128
snmp-server community	128
snmp-server contact	129
snmp-server enable traps	129
snmp-server engineID	130
snmp-server group	131
snmp-server host	132
snmp-server location	133
snmp-server user	133
snmp-server view	134
snmp-server vrf	135
Example: Configure SNMP	135
System clock	136
Time zones and UTC offset reference	137
System Clock commands	153
clock set	153
clock timezone	154
show clock	154
show clock timezone	154
Network Time Protocol	155
Enable NTP	156
Broadcasts	156
Source IP address	157
Authentication	157
Sample NTP configuration	158
NTP commands	161
ntp authenticate	161
ntp authentication-key	161
ntp broadcast client	162
ntp disable	162
ntp enable vrf	162
ntp master	163
ntp server	163
ntp source	163
ntp trusted-key	164
show ntp associations	164
show ntp status	165
Precision Time Protocol	166
Supported platforms	169
PTP installation scale and limits	169
Configuration notes	169
Configure Precision Time Protocol	170
View PTP information	173
Example: Configure boundary clock with L2 transport method	175
Example: Configure boundary clock with IPv4 multicast transport method	176
Example: Configure boundary clock with IPv4 unicast transport method	176
Example: Configure end-to-end transparent clock	177
Example: Configure boundary clock with IPv4 unicast transport method and L3 VLAN	178
Example: Configure PTP in a multinode setup	179
PTP commands	186
clear ptp counters	186
debug ptp	186
master	187
ptp announce	187
ptp clock	188
ptp delay-mechanism	188
ptp delay-req-min-interval	189
ptp domain	189
ptp enable	189
ptp local-priority	190
ptp priority1	190
ptp priority2	191
ptp role	191
ptp source	191
ptp sync-interval	192
ptp system-time enable	192
ptp transport	193
ptp vlan	194
show ptp	194
show ptp clock	195
show ptp counters	196
show ptp foreign-masters	197
show ptp interface	197
show ptp parent	198
show ptp peer	198
show ptp servo	199
show ptp time-properties	200
slave	200
source	201
Dynamic Host Configuration Protocol	201
Packet format and options	203
DHCP server	204
Automatic address allocation	204
Hostname resolution	206
Manual binding entries	206
View DHCP Information	208
DHCP relay agent	208
Option 82 for security	208
DHCP snooping	208
DHCP snooping examples	213
DHCP snooping switch as a relay agent	215
DHCP snooping in a Layer 2 VLT setup	216
DHCP snooping with DHCP relay agent in a VLT setup	219
Dynamic ARP inspection	222
Source Address Validation	224
System domain name and list	225
DHCP commands	226
DHCP relay commands	226
ip helper-address	226
ipv6 helper-address	227
ip dhcp-relay information-option	227
show vlt mismatch	228
DHCP server commands	232
default-router address	232
disable	232
domain-name	232
dns-server address	233
hardware-address	233
host	233
ip dhcp server	234
lease	234
netbios-name-server address	234
netbios-node-type	235
network	235
pool	235
range	236
show ip dhcp binding	236
DHCP snooping commands	237
arp inspection	237
arp inspection-trust	237
arp inspection violation logging	237
clear ip arp inspection statistics	238
clear ip dhcp snooping binding	238
ip dhcp snooping (global)	238
ip dhcp snooping (interface)	239
ip dhcp snooping binding	239
ip dhcp snooping trust	240
ip dhcp snooping verify mac-address	240
show ip arp inspection database	241
show ip arp inspection statistics	241
show ip arp inspection logging	241
show ip dhcp snooping binding	242
DNS commands	242
ip domain-list	242
ip domain-name	243
ip host	243
ip name-server	243
show hosts	244
Containers	244
Interfaces	247
Ethernet interfaces	247
Unified port groups	248
Z9264F-ON port-group profiles	249
Port-groups on S5200F-ON switches	250
L2 mode configuration	257
L3 mode configuration	258
Fibre Channel interfaces	259
Configuring wavelength	260
Management interface	261
Management interface	261
VLAN interfaces	261
User-configured default VLAN	262
VLAN scale profile	262
Loopback interfaces	263
Port-channel interfaces	264
Create port-channel	264
Add port member	264
Minimum links	265
Assign Port Channel IP Address	265
Remove or disable port-channel	266
Load balance traffic	266
Change hash algorithm	267
Configure interface ranges	267
Switch-port profiles	268
S4148-ON Series port profiles	269
S4148U-ON port profiles	269
Configure negotiation modes on interfaces	270
Configure breakout mode	272
Breakout auto-configuration	272
Reset default configuration	273
Forward error correction	274
Energy-efficient Ethernet	275
Enable energy-efficient Ethernet	276
Clear EEE counters	276
View EEE status/statistics	276
EEE commands	277
clear counters interface eee	277
clear counters interface ethernet eee	278
eee	278
show interface eee	278
show interface eee statistics	279
show interface ethernet eee	279
show interface ethernet eee statistics	279
View interface configuration	280
Digital optical monitoring	283
Enable DOM and DOM traps	284
Default MTU Configuration	285
Interface commands	286
channel-group	286
default interface	286
default vlan-id	289
description (Interface)	289
duplex	290
enable dom	290
enable dom traps	290
feature auto-breakout	291
fec	291
interface breakout	292
interface ethernet	292
interface loopback	293
interface mgmt	293
interface null	293
interface port-channel	294
interface range	294
interface vlan	295
link-bundle-utilization	295
mode	295
mode l3	296
mtu	297
negotiation	297
port mode Eth	298
port-group	299
profile	299
scale-profile vlan	300
show discovered-expanders	300
show interface	301
show interface transceiver “Tunable wavelength”	303
show inventory media	303
show link-bundle-utilization	304
show port-channel summary	305
show port-group	305
show switch-port-profile	306
show system	307
show unit-provision	307
show vlan	308
shutdown	308
speed (Fibre Channel)	309
speed (Management)	309
switch-port-profile	310
switchport access vlan	312
switchport mode	312
switchport trunk allowed vlan	313
unit-provision	313
wavelength	313
default mtu	314
show default mtu	314
PowerEdge MX Ethernet I/O modules	315
Operating modes	315
Changing operating modes	317
Restrictions	317
Port groups on I/O modules	317
Double-density QSFP28 interfaces	317
Virtual ports	320
Single-density QSFP28 interfaces	323
Server-facing interfaces	324
Replace MX Ethernet I/O modules	325
Deployment instructions	325
Replace an IOM in Full-Switch VLT	326
Replace an IOM in SmartFabric	326
Remove and replace the faulty IOM	326
Verify and configure IOM settings	326
Identify the master IOM	327
Log in to the master IOM from the member	328
Initiate the module replacement workflow	328
Connect the new IOM	329
MX-IOM Hardware Replacement	329
View SmartFabric Services configuration	329
Fibre Channel	331
Fibre Channel over Ethernet	332
Configure FIP snooping	333
Terminology	334
Virtual fabric	334
Fibre Channel zoning	337
F_Port on Ethernet	338
Pinning FCoE traffic to a specific port of a port-channel	339
Sample FSB configuration on VLT network	341
Sample FC Switch configuration on VLT network	343
Sample FSB configuration on non-VLT network	345
Sample FC Switch configuration on non-VLT network	346
Multiswitch fabric (E Port)	348
Configure multiswitch fabric (E Port)	350
Verify multiswitch fabric (E Port) configuration	352
Multiswitch fabric (E Port) CLI commands	357
show fc fspf interface	357
clear fc fabric statistics	358
clear fc flow-control-statistics	358
clear fc fspf statistics	359
clear fc ns switch statistics	359
domain-id	359
e_d_tov	360
fc port-mode F \| E	360
feature fc	361
fspf cost	361
fspf dead-interval	362
fspf hello-interval	362
fspf hold-time	362
fspf retransmit-interval	363
principal-priority	363
r_a_tov	364
show fc fabric	364
show fc fabric interface	365
show fc fabric statistics	365
show fc flow-control-statistics	366
show fc fspf database	367
show fc fspf neighbor	367
show fc fspf route	368
show fc ns fabric	368
show fc ns fabric brief	369
show fc ns switch statistics	369
show fc switch	370
show interface fibre channel	370
show vfabric	371
show vfabric fspf	372
Multi-hop FIP-snooping bridge	372
Configuration notes	373
Configure multi-hop FSB	373
Verify multi-hop FSB configuration	379
Sample Multi-hop FSB configuration	380
Configuration guidelines	393
NPIV Proxy Gateway cascading	394
Support for untagged VLAN in FCoE	396
Rebalance FC sessions (NPG)	396
Load balancing after system reboot	397
NPG rebalance topology	397
NPG switch configurations	397
Example: Manual rebalance trigger	399
Equivalent RESTCONF request for the rebalancing CLIs	401
F_Port commands	401
fc alias	402
fc zone	402
fc zoneset	402
feature fc	403
member (alias)	403
member (zone)	404
member (zoneset)	404
show fc alias	404
show fc interface-area-id mapping	405
show fc ns switch	405
show fc zone	406
show fc zoneset	406
zone default-zone permit	408
zoneset activate	408
NPG commands	408
fc port-mode F	408
feature fc npg	409
show npg devices	409
show npg uplink-interface	410
F_Port and NPG commands	411
clear fc statistics	412
fcoe	412
fcoe delay fcf-adv	412

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
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1,000
1,001
1,002
1,003
1,004
1,005
1,006
1,007
1,008
1,009
1,010
1,011
1,012
1,013
1,014
1,015
1,016
1,017
1,018
1,019
1,020
1,021
1,022
1,023
1,024
1,025
1,026
1,027
1,028
1,029
1,030
1,031
1,032
1,033
1,034
1,035
1,036
1,037
1,038
1,039
1,040
1,041
1,042
1,043
1,044
1,045
1,046
1,047
1,048
1,049
1,050
1,051
1,052
1,053
1,054
1,055
1,056
1,057
1,058
1,059
1,060
1,061
1,062
1,063
1,064
1,065
1,066
1,067
1,068
1,069
1,070
1,071
1,072
1,073
1,074
1,075
1,076
1,077
1,078
1,079
1,080
1,081
1,082
1,083
1,084
1,085
1,086
1,087
1,088
1,089
1,090
1,091
1,092
1,093
1,094
1,095
1,096
1,097
1,098
1,099
1,100
1,101
1,102
1,103
1,104
1,105
1,106
1,107
1,108
1,109
1,110
1,111
1,112
1,113
1,114
1,115
1,116
1,117
1,118
1,119
1,120
1,121
1,122
1,123
1,124
1,125
1,126
1,127
1,128
1,129
1,130
1,131
1,132
1,133
1,134
1,135
1,136
1,137
1,138
1,139
1,140
1,141
1,142
1,143
1,144
1,145
1,146
1,147
1,148
1,149
1,150
1,151
1,152
1,153
1,154
1,155
1,156
1,157
1,158
1,159
1,160
1,161
1,162
1,163
1,164
1,165
1,166
1,167
1,168
1,169
1,170
1,171
1,172
1,173
1,174
1,175
1,176
1,177
1,178
1,179
1,180
1,181
1,182
1,183
1,184
1,185
1,186
1,187
1,188
1,189
1,190
1,191
1,192
1,193
1,194
1,195
1,196
1,197
1,198
1,199
1,200
1,201
1,202
1,203
1,204
1,205
1,206
1,207
1,208
1,209
1,210
1,211
1,212
1,213
1,214
1,215
1,216
1,217
1,218
1,219
1,220
1,221
1,222
1,223
1,224
1,225
1,226
1,227
1,228
1,229
1,230
1,231
1,232
1,233
1,234
1,235
1,236
1,237
1,238
1,239
1,240
1,241
1,242
1,243
1,244
1,245
1,246
1,247
1,248
1,249
1,250
1,251
1,252
1,253
1,254
1,255
1,256
1,257
1,258
1,259
1,260
1,261
1,262
1,263
1,264
1,265
1,266
1,267
1,268
1,269
1,270
1,271
1,272
1,273
1,274
1,275
1,276
1,277
1,278
1,279
1,280
1,281
1,282
1,283
1,284
1,285
1,286
1,287
1,288
1,289
1,290
1,291
1,292
1,293
1,294
1,295
1,296
1,297
1,298
1,299
1,300
1,301
1,302
1,303
1,304
1,305
1,306
1,307
1,308
1,309
1,310
1,311
1,312
1,313
1,314
1,315
1,316
1,317
1,318
1,319
1,320
1,321
1,322
1,323
1,324
1,325
1,326
1,327
1,328
1,329
1,330
1,331
1,332
1,333
1,334
1,335
1,336
1,337
1,338
1,339
1,340
1,341
1,342
1,343
1,344
1,345
1,346
1,347
1,348
1,349
1,350
1,351
1,352
1,353
1,354
1,355
1,356
1,357
1,358
1,359
1,360
1,361
1,362
1,363
1,364
1,365
1,366
1,367
1,368
1,369
1,370
1,371
1,372
1,373
1,374
1,375
1,376
1,377
1,378
1,379
1,380
1,381
1,382
1,383
1,384
1,385
1,386
1,387
1,388
1,389
1,390
1,391
1,392
1,393
1,394
1,395
1,396
1,397
1,398
1,399
1,400
1,401
1,402
1,403
1,404
1,405
1,406
1,407
1,408
1,409
1,410
1,411
1,412
1,413
1,414
1,415
1,416
1,417
1,418
1,419
1,420
1,421
1,422
1,423
1,424
1,425
1,426
1,427
1,428
1,429
1,430
1,431
1,432
1,433
1,434
1,435
1,436
1,437
1,438
1,439
1,440
1,441
1,442
1,443
1,444
1,445
1,446
1,447
1,448
1,449
1,450
1,451
1,452
1,453
1,454
1,455
1,456
1,457
1,458
1,459
1,460
1,461
1,462
1,463
1,464
1,465
1,466
1,467
1,468
1,469
1,470
1,471
1,472
1,473
1,474
1,475
1,476
1,477
1,478
1,479
1,480
1,481
1,482
1,483
1,484
1,485
1,486
1,487
1,488
1,489
1,490
1,491
1,492
1,493
1,494
1,495
1,496
1,497
1,498
1,499
1,500
1,501
1,502
1,503
1,504
1,505
1,506
1,507
1,508
1,509
1,510
1,511
1,512
1,513
1,514
1,515
1,516
1,517
1,518
1,519
1,520
1,521
1,522
1,523
1,524
1,525
1,526
1,527
1,528
1,529
1,530
1,531
1,532
1,533
1,534
1,535
1,536
1,537
1,538
1,539
1,540
1,541
1,542
1,543
1,544
1,545
1,546
1,547
1,548
1,549
1,550
1,551
1,552
1,553
1,554
1,555
1,556
1,557
1,558
1,559
1,560
1,561
1,562
1,563
1,564
1,565
1,566
1,567
1,568
1,569
1,570
1,571
1,572
1,573
1,574
1,575
1,576
1,577
1,578
1,579
1,580
1,581
1,582
1,583
1,584
1,585
1,586
1,587
1,588
1,589
1,590
1,591
1,592
1,593
1,594
1,595
1,596
1,597

Match case Limit results 1 per page

Far-end failure detection

Far-End Failure Detection (FEFD) is a protocol that detects remote data link errors in a network.

FEFD uses a link layer echo protocol to detect and signal far-end failures over Ethernet and optical links. When you enable

FEFD, switches periodically exchange FEFD echo frames to identify link failures. If the local switch does not receive an echo

from its peer for the time interval of three times the configured FEFD message interval, the local switch assumes that the peer

link is down. The default interval for FEFD message interval is 15 seconds. For example, with the default configuration, if the

local switch does not receive an echo message for 45 seconds from its peer, it brings the peer link down.

FEFD helps detect far-end failure when the following problems occur:

●

Only one side receives packets although the physical layer (L1) of the link is up on both sides.

●

Transceivers are not connected to the correct ports.

FEFD states

FEFD comprises the following four states:

●

Idle

—FEFD is disabled.

●

Unknown

—Shown when FEFD is enabled and changes to

bi-directional

after successful handshake with the peer.

Also shown if the peer goes down in

normal

mode.

●

bi-directional

—Interface is up, connected, and receiving echoes of its neighbor.

●

err-disabled

—Only found when FEFD mode is

aggressive

and when the interface has not received three echoes of

its neighbor. To reset an interface in this state, use the

fefd reset

command.

FEFD modes

FEFD operates in two modes—Normal mode and aggressive mode.

●

Normal mode—When you enable Normal mode on an interface and a far-end failure is detected, no intervention is required

to reset the interface to bring it back to an FEFD operational state.

●

Aggressive mode—When you enable Aggressive mode on an interface in the same state, you must manually reset the

interface.

The following events explain how FEFD state transition occurs:

●

When you enable FEFD on an interface a link transitions from idle state to unknown state.

448

Layer 2