IPv6

Subnet prefix lengths

2402:9400:0000:0000:0000:0000:0000:0001
XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX
      ||| |||| |||| |||| |||| |||| ||||
      ||| |||| |||| |||| |||| |||| |||128
      ||| |||| |||| |||| |||| |||| ||124
      ||| |||| |||| |||| |||| |||| |120
      ||| |||| |||| |||| |||| |||| 116
      ||| |||| |||| |||| |||| |||112
      ||| |||| |||| |||| |||| ||108
      ||| |||| |||| |||| |||| |104
      ||| |||| |||| |||| |||| 100
      ||| |||| |||| |||| |||96
      ||| |||| |||| |||| ||92
      ||| |||| |||| |||| |88
      ||| |||| |||| |||| 84
      ||| |||| |||| |||80
      ||| |||| |||| ||76
      ||| |||| |||| |72
      ||| |||| |||| 68
      ||| |||| |||64
      ||| |||| ||60
      ||| |||| |56
      ||| |||| 52
      ||| |||48
      ||| ||44
      ||| |40
      ||| 36
      ||32
      |28
      24

Subnet size

IPv6 CIDR Subnet	Number of IPs
/128	1
/127	2
/126	4
/125	8
/124	16
/123	32
/122	64
/121	128
/120	256
/119	512
/118	1,024
/117	2,048
/116	4,096
/115	8,192
/114	16,384
/113	32,768
/112	65,536
/111	131,072
/110	262,144
/109	524,288
/108	1,048,576
/107	2,097,152
/106	4,194,304
/105	8,388,608
/104	16,777,216
/103	33,554,432
/102	67,108,864
/101	134,217,728
/100	268,435,456
/99	536,870,912
/98	1,073,741,824
/97	2,147,483,648
/96	4,294,967,296
/95	8,589,934,592
/94	17,179,869,184
/93	34,359,738,368
/92	68,719,476,736
/91	137,438,953,472
/90	274,877,906,944
/89	549,755,813,888
/88	1,099,511,627,776
/87	2,199,023,255,552
/86	4,398,046,511,104
/85	8,796,093,022,208
/84	17,592,186,044,416
/83	35,184,372,088,832
/82	70,368,744,177,664
/81	140,737,488,355,328
/80	281,474,976,710,656
/79	562,949,953,421,312
/78	1,125,899,906,842,624
/77	2,251,799,813,685,248
/76	4,503,599,627,370,496
/75	9,007,199,254,740,992
/74	18,014,398,509,481,985
/73	36,028,797,018,963,968
/72	72,057,594,037,927,936
/71	144,115,188,075,855,872
/70	288,230,376,151,711,744
/69	576,460,752,303,423,488
/68	1,152,921,504,606,846,976
/67	2,305,843,009,213,693,952
/66	4,611,686,018,427,387,904
/65	9,223,372,036,854,775,808
Residential – /64	18,446,744,073,709,551,616
/63	36,893,488,147,419,103,232
/62	73,786,976,294,838,206,464
/61	147,573,952,589,676,412,928
/60	295,147,905,179,352,825,856
/59	590,295,810,358,705,651,712
/58	1,180,591,620,717,411,303,424
/57	2,361,183,241,434,822,606,848
/56	4,722,366,482,869,645,213,696
/55	9,444,732,965,739,290,427,392
/54	18,889,465,931,478,580,854,784
/53	37,778,931,862,957,161,709,568
/52	75,557,863,725,914,323,419,136
/51	151,115,727,451,828,646,838,272
/50	302,231,454,903,657,293,676,544
/49	604,462,909,807,314,587,353,088
Business – /48	1,208,925,819,614,629,174,706,176
/47	2,417,851,639,229,258,349,412,352
/46	4,835,703,278,458,516,698,824,704
/45	9,671,406,556,917,033,397,649,408
/44	19,342,813,113,834,066,795,298,816
/43	38,685,626,227,668,133,590,597,632
/42	77,371,252,455,336,267,181,195,264
/41	154,742,504,910,672,534,362,390,528
/40	309,485,009,821,345,068,724,781,056
/39	618,970,019,642,690,137,449,562,112
/38	1,237,940,039,285,380,274,899,124,224
/37	2,475,880,078,570,760,549,798,248,448
/36	4,951,760,157,141,521,099,596,496,896
/35	9,903,520,314,283,042,199,192,993,792
/34	19,807,040,628,566,084,398,385,987,584
/33	39,614,081,257,132,168,796,771,975,168
ISP – /32	79,228,162,514,264,337,593,543,950,336
/31	158,456,325,028,528,675,187,087,900,672
/30	316,912,650,057,057,350,374,175,801,344
/29	633,825,300,114,114,700,748,351,602,688
/28	1,267,650,600,228,229,401,496,703,205,376
/27	2,535,301,200,456,458,802,993,406,410,752
/26	5,070,602,400,912,917,605,986,812,821,504
/25	10,141,204,801,825,835,211,973,625,643,008
/24	20,282,409,603,651,670,423,947,251,286,016
/23	40,564,819,207,303,340,847,894,502,572,032
/22	81,129,638,414,606,681,695,789,005,144,064
/21	162,259,276,829,213,363,391,578,010,288,128
/20	324,518,553,658,426,726,783,156,020,576,256
/19	649,037,107,316,853,453,566,312,041,152,512
/18	1,298,074,214,633,706,907,132,624,082,305,024
/17	2,596,148,429,267,413,814,265,248,164,610,048
/16	5,192,296,858,534,827,628,530,496,329,220,096
/15	10,384,593,717,069,655,257,060,992,658,440,192
/14	20,769,187,434,139,310,514,121,985,316,880,384
/13	41,538,374,868,278,621,028,243,970,633,760,768
/12	83,076,749,736,557,242,056,487,941,267,521,536
/11	166,153,499,473,114,484,112,975,882,535,043,072
/10	332,306,998,946,228,968,225,951,765,070,086,144
/9	664,613,997,892,457,936,451,903,530,140,172,288
/8	1,329,227,995,784,915,872,903,807,060,280,344,576

Example allocations

/64 IPv6 allocations are usually given to end users, who do not require any VLANs. It allows auto configuration, or SLAAC so makes life a lot easier when configuring.

2402:9400:1000:0::/64
2402:9400:1000:1::/64
2402:9400:1000:2::/64
2402:9400:1000:3::/64
2402:9400:1000:4::/64
2402:9400:1000:5::/64
2402:9400:1000:6::/64
2402:9400:1000:7::/64
2402:9400:1000:8::/64
2402:9400:1000:9::/64
2402:9400:1000:a::/64
2402:9400:1000:b::/64
2402:9400:1000:c::/64
2402:9400:1000:e::/64
2402:9400:1000:e::/64
2402:9400:1000:f::/64
2402:9400:1000:10::/64
2402:9400:1000:11::/64

/48 allocations are usually provided to business, who require additional VLANs or may require the range to be split up.

2402:9400:10::/48
2402:9400:11::/48
2402:9400:12::/48
2402:9400:13::/48
2402:9400:14::/48
2402:9400:15::/48
2402:9400:16::/48
2402:9400:17::/48
2402:9400:18::/48
2402:9400:19::/48
2402:9400:1a::/48
2402:9400:1b::/48
2402:9400:1c::/48
2402:9400:1e::/48
2402:9400:1f::/48
2402:9400:20::/48