Home » Dell Manuals » Servers » Dell Force10 S50-01-GE-48T » Manual Viewer

Dell Force10 S50-01-GE-48T FTOS 8.4.2.7 Configuration Guide for E-Series TeraS - Page 1109

Virtual Routing and Forwarding (VRF)

View all Dell Force10 S50-01-GE-48T manuals

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

Page 1109 highlights

57 Virtual Routing and Forwarding (VRF) e Virtual Routing and Forwarding (VRF) (VRF) is supported only on platform: VRF allows a physical router to partition itself into multiple Virtual Routers (VRs). The control and data plane are isolated in each VR so that traffic does NOT flow across VRs.Virtual Routing and Forwarding (VRF) allows multiple instances of a routing table to co-exist within the same router at the same time. VRF improves functionality by allowing network paths to be segmented without using multiple devices. Using VRF also increases network security and can eliminate the need for encryption and authentication due to traffic segmentation. Internet service providers (ISPs) often take advantage of VRF to create separate virtual private networks (VPNs) for customers; VRF is also referred to as VPN routing and forwarding. VRF is implemented in a network device by having a distinct Forwarding Information Base (FIB) per VRF instance. A network device has the ability to configure different virtual routers, so that each has its own FIB that is not accessible to any other virtual router instance on the same device. VRF acts like a logical router; while a physical router may include many routing tables, a VRF instance uses only a single routing table. VRF uses a forwarding table that designates the next hop for each data packet, a list of devices that may be called upon to forward the packet, and a set of rules and routing protocols that govern how the packet is forwarded. These VRF forwarding tables prevent traffic from being forwarded outside a specific VRF path and also keep out traffic that should remain outside the VRF path. VRF uses interfaces to distinguish routes for different VRF instances. Interfaces in a VRF can be either physical (Ethernet port or port channel) or logical (VLANs). Starting in release 8.4.1.0, you can configure identical or overlapping IP subnets on different interfaces if each interface belongs to a different VRF instance. Virtual Routing and Forwarding (VRF) | 1109

Section	Page
About this Guide	33
Objectives	33
Audience	33
Conventions	34
Information Symbols	34
Related Documents	34
Configuration Fundamentals	35
Accessing the Command Line	35
CLI Modes	36
Navigating CLI Modes	37
The do Command	40
Undoing Commands	40
Obtaining Help	41
Entering and Editing Commands	41
Command History	42
Filtering show Command Outputs	43
Multiple Users in Configuration mode	44
Getting Started	45
Default Configuration	46
Configure a Host Name	47
Access the System Remotely	47
Access the C-Series and E-Series Remotely	47
Configure the Management Port IP Address	48
Configure a Management Route	48
Configure a Username and Password	48
Access the S-Series Remotely	49
Configure the Enable Password	50
Configuration File Management	50
Copy Files to and from the System	51
Important Points to Remember	51
Save the Running-configuration	52
View Files	53
View Configuration Files	54
File System Management	55
View command history	56
Upgrading and Downgrading FTOS	56
System Management	57
Configure Privilege Levels	57
Create a Custom Privilege Level	57
Removing a command from EXEC mode	58
Move a command from EXEC Privilege mode to EXEC mode	58
Allow Access to CONFIGURATION mode commands	58
Allow Access to INTERFACE, LINE, ROUTE-MAP, and ROUTER mode	58
Apply a Privilege Level to a Username	61
Apply a Privilege Level to a Terminal Line	61
Configure Logging	61
Log Messages in the Logging Buffer	62
Configuration Task List for System Log Management	62
Disable System Logging	62
Send System Messages to a Syslog Server	63
Configure a Unix System as a Syslog Server	63
Change System Logging Settings	63
Display the Logging Buffer and the Logging Configuration	64
Configure a UNIX Logging Facility Level	66
Synchronize Log Messages	67
Enable Timestamp on Syslog Messages	67
File Transfer Services	68
Configuration Task List for File Transfer Services	68
Enable FTP server	68
Configure FTP server parameters	68
Configure FTP client parameters	69
Terminal Lines	69
Deny and Permit Access to a Terminal Line	69
Configure Login Authentication for Terminal Lines	70
Time out of EXEC Privilege Mode	71
Telnet to Another Network Device	72
Lock CONFIGURATION mode	72
Viewing the Configuration Lock Status	73
Recovering from a Forgotten Password	74
Recovering from a Forgotten Enable Password	75
Recovering from a Forgotten Password on S-Series	76
Recovering from a Failed Start	77
802.1ag	79
Ethernet CFM	79
Maintenance Domains	80
Maintenance Points	80
Maintenance End Points	81
Implementation Information	82
Configure CFM	82
Related Configuration Tasks	82
Enable Ethernet CFM	83
Create a Maintenance Domain	83
Create a Maintenance Association	84
Create Maintenance Points	84
Create a Maintenance End Point	84
Create a Maintenance Intermediate Point	85
MP Databases	85
MP Database Persistence	86
Continuity Check Messages	87
Enable CCM	88
Enable Cross-checking	88
Loopback Message and Response	88
Linktrace Message and Response	88
Link Trace Cache	89
Enable CFM SNMP Traps.	90
Display Ethernet CFM Statistics	91
802.3ah	93
Link Layer OAM Overview	93
Link Layer OAMPDUs	94
OAMPDU Flags	94
Link Layer OAM Operational Modes	95
Link Layer OAM Discovery	95
Link Layer OAM Events	96
Remote Loopback	96
Implementation Information	96
Configure Link Layer OAM	97
Related Configuration Tasks	97
Enable Link Layer OAM	97
Adjust the OAMPDU Transmission Parameters	99
Link Performance Event Monitoring	99
Enable Error Monitoring	99
Set Threshold Values	100
Symbol Errors per Second	100
Frame Errors per Second	101
Frame Errors per Frame Period	101
Error Seconds per Time Period	101
Execute an Action upon Exceeding the High Threshold	102
Remote Failure Indication	102
Remote Loopback	103
Display Link Layer OAM Configuration and Statistics	104
Manage Link Layer OAM	106
Enable MIB Retrieval Support/Function	106
Adjust the Size of the Link OAM Event Log	106
802.1X	107
Protocol Overview	107
The Port-authentication Process	109
EAP over RADIUS	110
RADIUS Attributes for 802.1 Support	111
Configuring 802.1X	111
Related Configuration Tasks	111
Important Points to Remember	112
Enabling 802.1X	112
Configuring Request Identity Re-transmissions	114
Configuring a Quiet Period after a Failed Authentication	114
Forcibly Authorizing or Unauthorizing a Port	115
Re-Authenticating a Port	116
Periodic Re-Authentication	116
Configuring Timeouts	117
Dynamic VLAN Assignment with Port Authentication	119
Guest and Authentication-Fail VLANs	121
Configuring a Guest VLAN	121
Configuring an Authentication-Fail VLAN	122
Multi-Host Authentication	123
Multi-Supplicant Authentication	125
MAC Authentication Bypass	127
MAB in Single-host and Multi-Host Mode	128
MAB in Multi-Supplicant Authentication Mode	128
Dynamic CoS with 802.1X	130
IP Access Control Lists (ACL), Prefix Lists, and Route-maps	133
Overview	133
IP Access Control Lists (ACLs)	134
CAM Profiling, CAM Allocation, and CAM Optimization	134
CAM Profiling	135
User Configurable CAM Allocation	135
CAM optimization	136
Test CAM Usage	136
Implementing ACLs on FTOS	137
ACLs and VLANs	137
ACL Optimization	137
Determine the order in which ACLs are used to classify traffic	138
IP Fragment Handling	138
IP fragments ACL examples	139
Layer 4 ACL rules examples	139
Configure a standard IP ACL	140
Configure an extended IP ACL	143
Configure filters with sequence number	143
Configure filters without sequence number	145
Established Flag	146
Configuring Layer 2 and Layer 3 ACLs on an Interface	146
Assign an IP ACL to an Interface	147
Counting ACL Hits	148
Configuring Ingress ACLs	149
Configuring Egress ACLs	149
Egress Layer 3 ACL Lookup for Control-plane IP Traffic	150
Configuring ACLs to Loopback	151
Applying an ACL on Loopback Interfaces	151
IP Prefix Lists	153
Implementation Information	153
Configuration Task List for Prefix Lists	153
Configure a prefix list	154
Use a prefix list for route redistribution	156
ACL Resequencing	157
Resequencing an ACL or Prefix List	158
Route Maps	160
Implementation Information	160
Important Points to Remember	161
Configuration Task List for Route Maps	161
Create a route map	161
Configure route map filters	163
Configure a route map for route redistribution	166
Configure a route map for route tagging	167
Continue clause	167
Bidirectional Forwarding Detection	169
Protocol Overview	169
How BFD Works	170
BFD packet format	170
BFD sessions	173
BFD three-way handshake	173
Session state changes	174
Important Points to Remember	175
Configuring Bidirectional Forwarding Detection	175
Configuring BFD for Physical Ports	176
Related configuration tasks	176
Enabling BFD globally	176
Establishing a session on physical ports	176
Changing physical port session parameters	178
Disabling and re-enabling BFD	179
Configuring BFD for Static Routes	180
Related configuration tasks	180
Establishing sessions for static routes	180
Changing static route session parameters	181
Disabling BFD for static routes	181
Configuring BFD for OSPF	182
Related configuration tasks	182
Establishing sessions with OSPF neighbors	182
Changing OSPF session parameters	184
Disabling BFD for OSPF	184
Configuring BFD for BGP	185
Prerequisites	185
Establishing sessions with BGP neighbors	185
Disabling BFD for BGP	187
Using BFD in a BGP Peer Group	187
Displaying BFD for BGP Information	188
Configuring BFD for IS-IS	193
Related configuration tasks	193
Establishing sessions with IS-IS neighbors	193
Changing IS-IS session parameters	194
Disabling BFD for IS-IS	195
Configuring BFD for VRRP	195
Related configuration tasks	195
Establishing sessions with all VRRP neighbors	195
Establishing VRRP sessions on VRRP neighbors	196
Changing VRRP session parameters	197
Disabling BFD for VRRP	198
Configuring BFD for VLANs	198
Related configuration tasks	199
Establishing sessions with VLAN neighbors	199
Changing session parameters	200
Disabling BFD for VLANs	200
Configuring BFD for Port-Channels	201
Related configuration tasks	201
Establishing sessions on port-channels	201
Changing port-channel session parameters	202
Disabling BFD for port-channels	202
Configuring Protocol Liveness	203
Troubleshooting BFD	203
Border Gateway Protocol IPv4 (BGPv4)	205
Protocol Overview	206
Autonomous Systems (AS)	206
Sessions and Peers	208
Establishing a session	208
Peer Groups	209
Route Reflectors	209
Confederations	210
Communities	210
BGP Attributes	211
Best Path Selection Criteria	211
Best Path selection details	212
Weight	214
Local Preference	214
Multi-Exit Discriminators (MEDs)	214
Origin	215
AS Path	216
Next Hop	217
Multiprotocol BGP	217
Implementing BGP with FTOS	217
Advertise IGP cost as MED for redistributed routes	217
Ignore Router-ID for some best-path calculations	218
4-Byte AS Numbers	218
AS4 Number Representation	219
Dynamic AS Number Notation application	220
AS Number Migration	221
BGP4 Management Information Base (MIB)	223
Important Points to Remember	223
Configuration Information	224
BGP Configuration	225
Defaults	225
Configuration Task List for BGP	225
Enable BGP	226
Configure AS4 Number Representations	230
Configure Peer Groups	232
BGP fast fall-over	235
Configure passive peering	238
Maintain existing AS numbers during an AS migration	239
Allow an AS number to appear in its own AS path	240
Enable graceful restart	241
Filter on an AS-Path attribute	243
Redistribute routes	246
Configure IP community lists	247
Manipulate the COMMUNITY attribute	250
Change MED attribute	251
Change LOCAL_PREFERENCE attribute	252
Change NEXT_HOP attribute	253
Change WEIGHT attribute	253
Enable multipath	254
Filter BGP routes	254
Configure BGP route reflectors	257
Aggregate routes	258
Configure BGP confederations	258
Enable route flap dampening	259
Change BGP timers	263
BGP neighbor soft-reconfiguration	263
Route map continue	265
MBGP Configuration	266
BGP Regular Expression Optimization	267
Retain NH in BGP Advertisement	267
Debugging BGP	267
Storing Last and Bad PDUs	268
Capturing PDUs	269
PDU Counters	271
Sample Configurations	271
Content Addressable Memory	281
Content Addressable Memory	281
CAM Profiles	282
Microcode	284
CAM Profiling for ACLs	285
Boot Behavior	286
When to Use CAM Profiling	287
Important Points to Remember	288
Differences Between EtherScale and TeraScale	288
Select CAM Profiles	288
CAM Allocation	289
Test CAM Usage	290
View CAM Profiles	291
View CAM-ACL settings	291
View CAM Usage	292
Configure IPv4Flow Sub-partitions	293
Configure Ingress Layer 2 ACL Sub-partitions	295
Return to the Default CAM Configuration	297
CAM Optimization	298
Applications for CAM Profiling	298
LAG Hashing	298
LAG Hashing based on Bidirectional Flow	299
CAM profile for the VLAN ACL group feature	299
Troubleshoot CAM Profiling	299
CAM Profile Mismatches	299
QoS CAM Region Limitation	300
Configuration Replace and Rollback	301
Archived Files	301
Configuring Configuration Replace and Rollback	302
Related Configuration Tasks	302
Important Points to Remember	302
Enabling the Archive Service	302
Archiving a Configuration File	303
Viewing the Archive Directory	303
Replacing the Current Running Configuration	303
Rolling Back to the Previous Configuration	304
Configuring an Archive File Maximum	305
Configuring Auto-archive	306
Copying and Deleting an Archive File	307
Viewing and Editing the Contents of an Archive File	307
Viewing the Difference between Configuration Files	308
Dynamic Host Configuration Protocol	311
Protocol Overview	311
DHCP Packet Format and Options	312
Assigning an IP Address using DHCP	313
Implementation Information	314
Configuration Tasks	314
Configure the System to be a DHCP Server	314
Configuration Tasks	315
Related Configuration Tasks	315
Configure the Server for Automatic Address Allocation	315
Create an IP Address Pool	315
Exclude Addresses from the Address Pool	316
Specify an Address Lease Time	316
Specify a Default Gateway	316
Enable DHCP Server	317
Configure a Method of Hostname Resolution	317
Address Resolution using DNS	317
Address Resolution using NetBIOS WINS	318
Allocate Addresses to BOOTP Clients	318
Create Manual Binding Entries	318
Check for Address Conflicts	319
DHCP Clear Commands	320
Configure the System to be a Relay Agent	320
Configure Secure DHCP	321
Option 82	322
DHCP Snooping	322
Enable DCHP snooping	323
Add a static entry in the binding table	324
Clear the binding table	324
Display the contents of the binding table	324
Drop DHCP packets on snooped VLANs only	325
Dynamic ARP Inspection	325
Bypass the ARP Inspection	327
Source Address Validation	327
IP Source Address Validation	328
DHCP MAC Source Address Validation	328
IP+MAC Source Address Validation	328
Equal Cost Multi-Path	331
ECMP for Flow-based Affinity (E-Series)	331
Configurable Hash Algorithm (E-Series)	331
Deterministic ECMP Next Hop	332
Configurable Hash Algorithm Seed	332
Configurable ECMP Hash Algorithm (C- and S-Series)	334
Force10 Resilient Ring Protocol	335
Protocol Overview	335
Ring Status	336
Ring Checking	336
Ring Failure	337
Ring Restoration	337
Multiple FRRP Rings	337
Member VLAN Spanning Two Rings Connected by One Switch	337
Important FRRP Points	338
Important FRRP Concepts	339
Implementing FRRP	340
FRRP Configuration	341
Create the FRRP group	341
Configure the Control VLAN	341
Configure and add the Member VLANs	343
Set FRRP Timers	344
Clear FRRP counters	344
Show FRRP configuration	345
Show FRRP information	345
Troubleshooting FRRP	345
Configuration Checks	345
Sample Configuration and Topology	345
Force10 Service Agent	347
Implementation Information	347
Configure Force10 Service Agent	348
Related Configuration Tasks	348
Enable Force10 Service Agent	348
Specify an SMTP Server for FTSA	349
Provide an Administrator E-mail Address	349
FTSA Messaging Service	350
Enable the FTSA Messaging Service	350
Add Additional Recipients of FTSA E-mails	351
Encrypt FTSA Messages	352
Create a PGP5 encryption key	353
Provide Administrator Contact Information	353
Set the Frequency of FTSA Type 3 Messages	354
Generate FTSA Type 4 Messages	354
Set Parameters FTSA Type 5 Messages	354
FTSA Message Types	355
FTSA Policies	357
Create an FTSA Policy Test List	358
Choose test conditions for a policy test list	358
Set the match criterion for test lists	361
Create a Policy Action List	361
Add actions to a policy action list	362
Create a Policy and Assign a Test and Action List	363
Additional Policy Configurations	364
FTSA Policy Sample Configurations	364
Line card state-change policy configuration	364
Excessive CRC-error policy configuration	369
Debugging FTSA	371
GARP VLAN Registration Protocol	373
Protocol Overview	373
Important Points to Remember	373
Configuring GVRP	374
Related Configuration Tasks	375
Enabling GVRP Globally	375
Enabling GVRP on a Layer 2 Interface	376
Configuring GVRP Registration	376
Configuring a GARP Timer	377
High Availability	379
Component Redundancy	380
RPM Redundancy	380
Boot the chassis with a single RPM	380
Boot the chassis with dual RPMs	381
Automatic and manual RPM failover	382
Communication between RPMs	383
Support for RPM redundancy by FTOS version	384
RPM synchronization	385
RPM redundancy configuration tasks	385
Online Insertion and Removal	387
RPM Online Insertion and Removal	387
Line Card Online Insertion and Removal	387
Pre-configure a line card slot	388
Replace a line card	389
Hitless Behavior	389
Graceful Restart	390
Software Resiliency	390
Runtime System Health Check	391
SFM Channel Monitoring	391
Software Component Health Monitoring	392
System Health Monitoring	392
Failure and Event Logging	392
Trace Log	392
Core Dumps	392
System Log	393
Hot-lock Behavior	393
Warm Upgrade	393
Configure Cache Boot	394
Cache Boot Pre-requisites	394
Select the Cache Boot Image	396
In-Service Modular Hot-Fixes	398
Process Restartability	399
Internet Group Management Protocol	403
IGMP Implementation Information	403
IGMP Protocol Overview	403
IGMP version 2	404
Joining a Multicast Group	404
Leaving a Multicast Group	405
IGMP version 3	405
Joining and Filtering Groups and Sources	406
Leaving and Staying in Groups	407
Configuring IGMP	408
Related Configuration Tasks	408
Viewing IGMP Enabled Interfaces	408

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

Match case Limit results 1 per page

Virtual Routing and Forwarding (VRF)

1109

Virtual Routing and Forwarding (VRF)

(VRF) is supported only on platform:

VRF allows a physical router to partition itself into multiple Virtual Routers (VRs). The control and data

plane are isolated in each VR so that traffic does NOT flow across VRs.Virtual Routing and Forwarding

(VRF) allows multiple instances of a routing table to co-exist within the same router at the same time.

VRF improves functionality by allowing network paths to be segmented without using multiple devices.

Using VRF also increases network security and can eliminate the need for encryption and authentication

due to traffic segmentation. Internet service providers (ISPs) often take advantage of VRF to create

separate virtual private networks (VPNs) for customers; VRF is also referred to as VPN routing and

forwarding.

VRF is implemented in a network device by having a distinct Forwarding Information Base (FIB) per VRF

instance. A network device has the ability to configure different virtual routers, so that each has its own

FIB that is not accessible to any other virtual router instance on the same device.

VRF acts like a logical router; while a physical router may include many routing tables, a VRF instance

uses only a single routing table. VRF uses a forwarding table that designates the next hop for each data

packet, a list of devices that may be called upon to forward the packet, and a set of rules and routing

protocols that govern how the packet is forwarded. These VRF forwarding tables prevent traffic from

being forwarded outside a specific VRF path and also keep out traffic that should remain outside the VRF

path.

VRF uses interfaces to distinguish routes for different VRF instances. Interfaces in a VRF can be either

physical (Ethernet port or port channel) or logical (VLANs). Starting in release 8.4.1.0, you can configure

identical or overlapping IP subnets on different interfaces if each interface belongs to a different VRF

instance.