Download  Print this page

Helpful Hints For Creating Ethernet Services Access Lists; Source And Destination Addresses; Ethernet Services Access List Entry Sequence Numbering; Sequence Numbering Behavior - Cisco ASR 9000 Series Configuration Manuallines

L2vpn and ethernet services configuration guide.
Hide thumbs
   
1
2
Table of Contents
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

Advertisement

Implementing of Layer 2 Access Lists
• If no conditions match, the software drops the packet because each access list ends with an unwritten or
• The access list should contain at least one permit statement or else all packets are denied.
• Because the software stops testing conditions after the first match, the order of the conditions is critical.
• Inbound access lists process packets arriving at the router. Incoming packets are processed before being
• Outbound access lists process packets before they leave the router. Incoming packets are routed to the
• An access list can not be removed if that access list is being applied by an access group in use. To remove
• An access list must exist before you can use the ethernet-services access-group command.

Helpful Hints for Creating Ethernet Services Access Lists

Consider these when creating an Ethernet services access list:
• Create the access list before applying it to an interface.
• Organize your access list so that more specific references appear before more general ones.

Source and Destination Addresses

Source MAC address and destination MAC address are two of the most typical fields on which to base an
access list. Specify source MAC addresses to control packets from certain networking devices or hosts. Specify
destination MAC addresses to control packets being sent to certain networking devices or hosts.

Ethernet Services Access List Entry Sequence Numbering

The ability to apply sequence numbers to Ethernet services access-list entries simplifies access list changes.
The access list entry sequence numbering feature allows you to add sequence numbers to access-list entries
and resequence them. When you add a new entry, you choose the sequence number so that it is in a desired
position in the access list. If necessary, entries currently in the access list can be resequenced to create room
to insert the new entry.

Sequence Numbering Behavior

These details the sequence numbering behavior:
• If entries with no sequence numbers are applied, the first entry is assigned a sequence number of 10, and
implicit deny statement. That is, if the packet has not been permitted or denied by the time it was tested
against each statement, it is denied.
The same permit or deny statements specified in a different order could result in a packet being passed
under one circumstance and denied in another circumstance.
routed to an outbound interface. An inbound access list is efficient because it saves the overhead of
routing lookups if the packet is to be discarded because it is denied by the filtering tests. If the packet is
permitted by the tests, it is then processed for routing. For inbound lists, permit means continue to process
the packet after receiving it on an inbound interface; deny means discard the packet.
outbound interface and then processed through the outbound access list. For outbound lists, permit means
send it to the output buffer; deny means discard the packet.
an access list, remove the access group that is referencing the access list and then remove the access list.
successive entries are incremented by 10. The maximum sequence number is 2147483646. If the generated
sequence number exceeds this maximum number, this message is displayed:
L2VPN and Ethernet Services Configuration Guide for Cisco ASR 9000 Series Routers, IOS XR Release 6.3.x
Helpful Hints for Creating Ethernet Services Access Lists
465

Advertisement

Table of Contents

   Related Manuals for Cisco ASR 9000 Series

Comments to this Manuals

Symbols: 0
Latest comments: