Home » Dell Manuals » Hubs & Switches » Dell PowerConnect 8100 Series » Manual Viewer

Dell PowerConnect 8100 Series User's Configuration Guide - Page 666

What is Flow Control?, per interface, by defining the packet type and the rate at which the packets

View all Dell PowerConnect 8100 Series manuals

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

Page 666 highlights

For information about Priority Flow Control (PFC), which provides a way to distinguish which traffic on a physical link is paused when congestion occurs based on the priority of the traffic, see "Configuring Data Center Bridging Features" on page 799 What is Flow Control? IEEE 802.3 Annex 31B flow control allows nodes that transmit at slower speeds to communicate with higher speed switches by requesting that the higher speed switch refrain from sending packets. Transmissions are temporarily halted to prevent buffer overflows. Enabling the flow control feature allows PowerConnect 8000-series and 8100-series switches to process pause frames received from connected devices. PowerConnect switches do not transmit pause frames. Flow control is supported only on ports that are configured for full-duplex mode of operation. Since ports set to auto negotiate may not be added as LAG members, LAG member ports cannot have flow control configured to auto. What is Storm Control? A LAN storm is the result of an excessive number of broadcast, multicast, or unknown unicast messages simultaneously transmitted across a network by a single port. Forwarded message responses can overload network resources and cause network congestion. The storm control feature allows the switch to measure the incoming broadcast, multicast, and/or unknown unicast packet rate per port and discard packets when the rate exceeds the defined threshold. Storm control is enabled per interface, by defining the packet type and the rate at which the packets are transmitted. For each type of traffic (broadcast, multicast, or unknown unicast) you can configure a threshold level, which is expressed as a percentage of the total available bandwidth on the port. If the ingress rate of that type of packet is greater than the configured threshold level the port drops the excess traffic until the ingress rate for the packet type falls below the threshold. The actual rate of ingress traffic required to activate storm-control is based on the size of incoming packets and the hard-coded average packet size of 512 bytes - used to calculate a packet-per-second (pps) rate - as the forwardingplane requires PPS versus an absolute rate Kbps. For example, if the 666 Configuring Port-Based Traffic Control

Section	Page
Introduction	49
About This Document	49
Audience	50
Document Conventions	50
Additional Documentation	51
Switch Features	53
System Management Features	54
Multiple Management Options	54
System Time Management	54
Log Messages	54
Integrated DHCP Server	55
Management of Basic Network Information	55
IPv6 Management Features	55
Dual Software Images	55
File Management	56
Switch Database Management Templates	56
Automatic Installation of Firmware and Configuration	56
sFlow	57
SNMP Alarms and Trap Logs	57
CDP Interoperability through ISDP	57
Remote Monitoring (RMON)	57
Stacking Features	58
High Port Count	58
Single IP Management	58
Automatic Firmware Update for New Stack Members	58
Master Failover with Transparent Transition	59
Nonstop Forwarding on the Stack	59
Hot Add/Delete and Firmware Synchronization	59
Security Features	59
Configurable Access and Authentication Profiles	59
Password-Protected Management Access	60
Strong Password Enforcement	60
TACACS+ Client	60
RADIUS Support	60
SSH/SSL	61
Inbound Telnet Control	61
Denial of Service	61
Port Protection	61
Captive Portal	62
Dot1x Authentication (IEEE 802.1X)	62
MAC-Based 802.1X Authentication	62
Dot1x Monitor Mode	63
MAC-Based Port Security	63
Access Control Lists (ACL)	63
Time-Based ACLs	64
IP Source Guard (IPSG)	64
DHCP Snooping	64
Dynamic ARP Inspection	64
Protected Ports (Private VLAN Edge)	65
Switching Features	65
Flow Control Support (IEEE 802.3x)	65
Head of Line Blocking Prevention	65
Alternate Store and Forward (ASF)	65
Jumbo Frames Support	66
Auto-MDI/MDIX Support	66
VLAN-Aware MAC-based Switching	66
Back Pressure Support	66
Auto Negotiation	67
Broadcast Storm Control	67
Port Mirroring	67
Static and Dynamic MAC Address Tables	68
Link Layer Discovery Protocol (LLDP)	68
Link Layer Discovery Protocol (LLDP) for Media Endpoint Devices	68
Priority-based Flow Control (PFC)	68
Data Center Bridging Exchange (DBCx) Protocol	69
Enhanced Transmission Selection	69
Fibre Channel over Ethernet (FCoE) Initialization Protocol Snooping	69
Cisco Protocol Filtering	70
DHCP Layer 2 Relay	70
Virtual Local Area Network Supported Features	70
VLAN Support	70
Port-Based VLANs	70
IP Subnet-based VLAN	71
MAC-based VLAN	71
IEEE 802.1v Protocol-Based VLANs	71
GARP and GVRP Support	71
Voice VLAN	71
Guest VLAN	72
Double VLANs	72
Spanning Tree Protocol Features	73
Spanning Tree Protocol (STP)	73
Spanning Tree Port Settings	73
Rapid Spanning Tree	73
Multiple Spanning Tree	73
Bridge Protocol Data Unit (BPDU) Guard	74
BPDU Filtering	74
Link Aggregation Features	74
Link Aggregation	74
Link Aggregate Control Protocol (LACP)	74
Routing Features	76
Address Resolution Protocol (ARP) Table Management	76
VLAN Routing	76
IP Configuration	76
Open Shortest Path First (OSPF)	76
BOOTP/DHCP Relay Agent	77
IP Helper and UDP Relay	77
Routing Information Protocol	77
Router Discovery	77
Routing Table	77
Virtual Router Redundancy Protocol (VRRP)	78
Tunnel and Loopback Interfaces	78
IPv6 Routing Features	78
IPv6 Configuration	78
IPv6 Routes	79
OSPFv3	79
DHCPv6	79
Quality of Service (QoS) Features	80
Differentiated Services (DiffServ)	80
Class Of Service (CoS)	80
Auto Voice over IP (VoIP)	80
Internet Small Computer System Interface (iSCSI) Optimization	81
Layer 2 Multicast Features	81
MAC Multicast Support	81
IGMP Snooping	81
IGMP Snooping Querier	82
MLD Snooping	82
Multicast VLAN Registration	82
Layer 3 Multicast Features	83
Distance Vector Multicast Routing Protocol	83
Internet Group Management Protocol	83
IGMP Proxy	83
Protocol Independent Multicast—Dense Mode	83
Protocol Independent Multicast—Sparse Mode	84
Protocol Independent Multicast—Source Specific Multicast	84
Protocol Independent Multicast IPv6 Support	84
MLD/MLDv2 (RFC2710/RFC3810)	84
Hardware Overview	85
PowerConnect 8000-series and 8100-series Front Panel	85
PowerConnect 8024 Front Panel	85
PowerConnect 8024F Front Panel	86
PowerConnect 8132 Front Panel	87
PowerConnect 8132F Front Panel	87
PowerConnect 8164 Front Panel	88
PowerConnect 8164F Front Panel	89
Hot-Pluggable Interface Modules	90
USB Port (Power Connect 8100-series switches only)	92
Port and System LEDs	92
PowerConnect 8000-series and 8100-series Back Panel	92
Console Port	93
Out-of-Band Management Port	93
Power Supplies	93
Ventilation System	94
LED Definitions	95
Port LEDs	95
System LEDs	96
Switch Addresses	97
Using Dell OpenManage Switch Administrator	101
About Dell OpenManage Switch Administrator	101
Starting the Application	102
Understanding the Interface	103
Defining Fields	105
Understanding the Device View	106
Using the Device View Port Features	106
Using the Command-Line Interface	107
Accessing the Switch Through the CLI	107
Console Connection	107
Telnet Connection	108
Understanding Command Modes	109
Entering CLI Commands	111
Using the Question Mark to Get Help	111
Using Command Completion	112
Entering Abbreviated Commands	112
Negating Commands	112
Understanding Error Messages	113
Recalling Commands from the History Buffer	113
Default Settings	115
Setting the IP Address and Other Basic Network Information	119
IP Address and Network Information Overview	119
What Is the Basic Network Information?	119
Why Is Basic Network Information Needed?	120
How Is Basic Network Information Configured?	121
What Is Out-of-Band Management and In-Band Management?	121
Default Network Information	123
Configuring Basic Network Information (Web)	124
Out-of-Band Interface	124
IP Interface Configuration (Default VLAN IP Address)	125
Route Entry Configuration (Switch Default Gateway)	126
Domain Name Server	128
Default Domain Name	129
Host Name Mapping	130
Dynamic Host Name Mapping	131
Configuring Basic Network Information (CLI)	132
Enabling the DHCP Client on the OOB Port	132
Enabling the DHCP Client on the Default VLAN	132
Managing DHCP Leases	133
Configuring Static Network Information on the OOB Port	134
Configuring Static Network Information on the Default VLAN	134
Configuring and Viewing Additional Network Information	135
Basic Network Information Configuration Example	136
Managing QSFP Ports	139
Managing a Switch Stack	141
Stacking Overview	141
Creating a PowerConnect 8000/8100 Series Stack	142
How is the Stack Master Selected?	144
Adding a Switch to the Stack	145
Removing a Switch from the Stack	146
How is the Firmware Updated on the Stack?	147
What is Stacking Standby?	147
What is Nonstop Forwarding?	147
Switch Stack MAC Addressing and Stack Design Considerations	150
NSF Network Design Considerations	151
Why is Stacking Needed?	151
Default Stacking Values	152
Managing and Monitoring the Stack (Web)	153
Unit Configuration	153
Stack Summary	155
Stack Firmware Synchronization	156
Supported Switches	157
Stack Port Summary	158
Stack Port Counters	159
Stack Port Diagnostics	159
NSF Summary	160
Checkpoint Statistics	161
Managing the Stack (CLI)	162
Configuring Stack Member, Stack Port, and NSF Settings	162
Viewing and Clearing Stacking and NSF Information	164
Stacking and NSF Usage Scenarios	164
Basic Failover	166
Preconfiguring a Stack Member	168
NSF in the Data Center	170
NSF and VoIP	171
NSF and DHCP Snooping	172
NSF and the Storage Access Network	173
NSF and Routed Access	175
Configuring Authentication, Authorization, and Accounting	177
AAA Overview	177
Methods	178
Access Lines	179
Authentication	179
Authorization	180
Exec Authorization Capabilities	181
Accounting	182
Authentication Examples	183
Local Authentication Example	183
TACACS+ Authentication Example	184
RADIUS Authentication Example	186
Authorization Examples	187
Local Authorization Example—Direct Login to Privileged EXEC Mode	187
TACACS+ Authorization Example—Direct Login to Privileged EXEC Mode	187
TACACS+ Authorization Example—Administrative Profiles	188
TACACS+ Authorization Example—Custom Administrative Profile	189
TACACS+ Authorization Example—Per-command Authorization	190
RADIUS Authorization Example—Direct Login to Privileged EXEC Mode	191
RADIUS Authorization Example—Administrative Profiles	191
Using RADIUS Servers to Control Management Access	192
How Does RADIUS Control Management Access?	192
Which RADIUS Attributes Does the Switch Support?	194
How Are RADIUS Attributes Processed on the Switch?	196
Using TACACS+ Servers to Control Management Access	197
Which TACACS+ Attributes Does the Switch Support?	198
Default Configurations	199
Method Lists	199
Access Lines (AAA)	199
Access Lines (Non-AAA)	200
Administrative Profiles	200
Monitoring and Logging System Information	203
System Monitoring Overview	203
What System Information Is Monitored?	203
Why Is System Information Needed?	204
Where Are Log Messages Sent?	204
What Are the Severity Levels?	205
What Are the System Startup and Operation Logs?	205
What Is the Log Message Format?	206
What Factors Should Be Considered When Configuring Logging?	207
Default Log Settings	207
Monitoring System Information and Configuring Logging (Web)	208
Device Information	208
System Health	209
System Resources	210
Integrated Cable Test for Copper Cables	211
Optical Transceiver Diagnostics	212
Log Global Settings	214
RAM Log	215
Log File	216
Remote Log Server	216
Email Alert Global Configuration	219
Email Alert Mail Server Configuration	220
Email Alert Subject Configuration	222
Email Alert To Address Configuration	223
Email Alert Statistics	224
Monitoring System Information and Configuring Logging (CLI)	225
Viewing System Information	225
Running Cable Diagnostics	225
Configuring Local Logging	226
Configuring Remote Logging	228
Configuring Mail Server Settings	229
Configuring Email Alerts for Log Messages	230
Logging Configuration Examples	232
Configuring Local and Remote Logging	232
Configuring Email Alerting	233
Managing General System Settings	237
System Settings Overview	237
Why Does System Information Need to Be Configured?	238
What Are SDM Templates?	239
Why is the System Time Needed?	240
How Does SNTP Work?	240
Default General System Information	240
Configuring General System Settings (Web)	241
System Information	241
CLI Banner	244
SDM Template Preference	245
Clock	246
SNTP Global Settings	247
SNTP Authentication	248
SNTP Server	250
Summer Time Configuration	254
Time Zone Configuration	255
Slot Summary	256
Supported Cards	257
Configuring System Settings (CLI)	258
Configuring System Information	258
Configuring the Banner	259
Managing the SDM Template	260
Configuring SNTP Authentication and an SNTP Server	260
Setting the System Time and Date Manually	262
Viewing Slot Information	263
General System Settings Configuration Examples	264
Configuring System and Banner Information	264
Configuring SNTP	267
Configuring the Time Manually	269
Configuring SNMP	271
SNMP Overview	271
What Is SNMP?	271
What Are SNMP Traps?	272
Why Is SNMP Needed?	273
Default SNMP Values	273
Configuring SNMP (Web)	275
SNMP Global Parameters	275
SNMP View Settings	276
Access Control Group	278
SNMPv3 User Security Model (USM)	280
Communities	283
Notification Filter	285
Notification Recipients	286
Trap Flags	289
OSPFv2 Trap Flags	290
OSPFv3 Trap Flags	291
Trap Log	292
Configuring SNMP (CLI)	293
Configuring the SNMPv3 Engine ID	293
Configuring SNMP Views, Groups, and Users	294
Configuring Communities	297
Configuring SNMP Notifications (Traps and Informs)	299
SNMP Configuration Examples	302
Configuring SNMPv1 and SNMPv2	302
Configuring SNMPv3	303
Managing Images and Files	307
Image and File Management Overview	307
What Files Can Be Managed?	307
Why Is File Management Needed?	309
What Methods Are Supported for File Management?	311
What Factors Should Be Considered When Managing Files?	311
How Is the Running Configuration Saved?	313
Managing Images and Files (Web)	314
File System	314
Active Images	315
USB Flash Drive	316
File Download	317
File Upload	319
Copy Files	321
Managing Images and Files (CLI)	322
Downloading and Activating a New Image (TFTP)	322
Managing Files in Internal Flash	323
Managing Files on a USB Flash Device (PowerConnect 8100-series switches only)	324
Uploading a Configuration File (SCP)	324
Managing Configuration Scripts (SFTP)	325
File and Image Management Configuration Examples	326
Upgrading the Firmware	326
Managing Configuration Scripts	329
Managing Files by Using the USB Flash Drive (PowerConnect 8100- series switches only)	331
Automatically Updating the Image and Configuration	333
Auto Configuration Overview	333
What Is USB Auto Configuration?	334
What Files Does USB Auto Configuration Use?	334
What Is the DHCP Auto Configuration Process?	335
Monitoring and Completing the DHCP Auto Configuration Process	339
What Are the Dependencies for DHCP Auto Configuration?	340
Default Auto Configuration Values	341
Managing Auto Configuration (Web)	342
Auto-Install Configuration	342
Managing Auto Configuration (CLI)	343
Managing Auto Configuration	343
Auto Configuration Example	344
Enabling DHCP Auto Configuration and Auto Image Download	344
Monitoring Switch Traffic	347
Traffic Monitoring Overview	347
What is sFlow Technology?	347
What is RMON?	350
What is Port Mirroring?	351
Why is Traffic Monitoring Needed?	352
Default Traffic Monitoring Values	352
Monitoring Switch Traffic (Web)	353
sFlow Agent Summary	353
sFlow Receiver Configuration	354
sFlow Sampler Configuration	355
sFlow Poll Configuration	356
Interface Statistics	357
Etherlike Statistics	358
GVRP Statistics	359
EAP Statistics	360
Utilization Summary	361
Counter Summary	362
Switchport Statistics	363
RMON Statistics	364
RMON History Control Statistics	365
RMON History Table	367
RMON Event Control	368
RMON Event Log	370
RMON Alarms	371
Port Statistics	373
LAG Statistics	374
Port Mirroring	375
Monitoring Switch Traffic (CLI)	378
Configuring sFlow	378
Configuring RMON	380
Viewing Statistics	382
Configuring Port Mirroring	383
Traffic Monitoring Configuration Examples	384
Configuring sFlow	384
Configuring RMON	386
Configuring iSCSI Optimization	387
iSCSI Optimization Overview	387
What Does iSCSI Optimization Do?	388
How Does the Switch Detect iSCSI Traffic Flows?	388
How Is Quality of Service Applied to iSCSI Traffic Flows?	388
How Does iSCSI Optimization Use ACLs?	389
What Information Does the Switch Track in iSCSI Traffic Flows?	389
How Does iSCSI Optimization Interact With Dell EqualLogic Arrays?	390
What Occurs When iSCSI Optimization Is Enabled or Disabled?	390
How Does iSCSI Optimization Interact with DCBx?	391
How Does iSCSI Optimization Interact with Dell Compellent Arrays?	391
Default iSCSI Optimization Values	392
Configuring iSCSI Optimization (Web)	393
iSCSI Global Configuration	393
iSCSI Targets Table	394
iSCSI Sessions Table	395
iSCSI Sessions Detailed	396
Configuring iSCSI Optimization (CLI)	397
iSCSI Optimization Configuration Examples	399
Configuring iSCSI Optimization Between Servers and a Disk Array	399
Configuring a Captive Portal	401
Captive Portal Overview	401
What Does a Captive Portal Do?	401
Is the Captive Portal Feature Dependent on Any Other Feature?	402
What Factors Should Be Considered When Designing and Configuring a Captive Portal?	403
How Does Captive Portal Work?	404
What Captive Portal Pages Can Be Customized?	405
Default Captive Portal Behavior and Settings	406
Configuring the Captive Portal (Web)	408
Captive Portal Global Configuration	408
Captive Portal Configuration	409
Local User	414
User Group	418
Interface Association	420
Captive Portal Global Status	421
Captive Portal Activation and Activity Status	422
Interface Activation Status	423
Interface Capability Status	424
Client Summary	425
Client Detail	426
Captive Portal Interface Client Status	427
Captive Portal Client Status	428
Configuring a Captive Portal (CLI)	429
Configuring Global Captive Portal Settings	429
Creating and Configuring a Captive Portal	430
Configuring Captive Portal Groups and Users	433
Managing Captive Portal Clients	434
Captive Portal Configuration Example	435
Configuration Overview	436
Detailed Configuration Procedures	437
Configuring Port Characteristics	439
Port Overview	439
What Physical Port Characteristics Can Be Configured?	439
What is Link Dependency?	440
What Interface Types are Supported?	442
What is Interface Configuration Mode?	442
Default Port Values	444
Configuring Port Characteristics (Web)	445
Port Configuration	445
Link Dependency Configuration	448
Link Dependency Summary	450
Configuring Port Characteristics (CLI)	451
Configuring Port Settings	451
Configuring Link Dependencies	452
Port Configuration Examples	454
Configuring Port Settings	454
Configuring a Link Dependency Groups	455
Configuring Port and System Security	457
IEEE 802.1X	458
What is IEEE 802.1X?	458
What are the 802.1X Port States?	459
What is MAC-Based 802.1X Authentication?	460
What is the Role of 802.1X in VLAN Assignment?	461
What is Monitor Mode?	463
How Does the Authentication Server Assign DiffServ Filters?	465
What is the Internal Authentication Server?	465
Default 802.1X Values	466
Configuring IEEE 802.1X (Web)	467
Configuring IEEE 802.1X (CLI)	476
Configuring Internal Authentication Server Users	481

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

Match case Limit results 1 per page

666

Configuring Port-Based Traffic Control

For information about Priority Flow Control (PFC), which provides a way to

distinguish which traffic on a physical link is paused when congestion occurs

based on the priority of the traffic, see "Configuring Data Center Bridging

Features" on page 799

What is Flow Control?

IEEE 802.3 Annex 31B flow control allows nodes that transmit at slower

speeds to communicate with higher speed switches by requesting that the

higher speed switch refrain from sending packets. Transmissions are

temporarily halted to prevent buffer overflows. Enabling the flow control

feature allows PowerConnect 8000-series and 8100-series switches to process

pause frames received from connected devices. PowerConnect switches do

not transmit pause frames.

Flow control is supported only on ports that are configured for full-duplex

mode of operation. Since ports set to auto negotiate may not be added as

LAG members, LAG member ports cannot have flow control configured to

auto.

What is Storm Control?

A LAN storm is the result of an excessive number of broadcast, multicast, or

unknown unicast messages simultaneously transmitted across a network by a

single port. Forwarded message responses can overload network resources and

cause network congestion.

The storm control feature allows the switch to measure the incoming

broadcast, multicast, and/or unknown unicast packet rate per port and discard

packets when the rate exceeds the defined threshold. Storm control is enabled

per interface, by defining the packet type and the rate at which the packets

are transmitted. For each type of traffic (broadcast, multicast, or unknown

unicast) you can configure a threshold level, which is expressed as a

percentage of the total available bandwidth on the port. If the ingress rate of

that type of packet is greater than the configured threshold level the port

drops the excess traffic until the ingress rate for the packet type falls below

the threshold.

The actual rate of ingress traffic required to activate storm-control is based on

the size of incoming packets and the hard-coded average packet size of 512

bytes - used to calculate a packet-per-second (pps) rate - as the forwarding-

plane requires PPS versus an absolute rate Kbps. For example, if the