Are you ready?

Internet Protocol assigns unique addresses to allow communication over a network. IPv4 (Internet Protocol version 4), the current version used to assign these addresses, contains just over four billion unique IP addresses. IPv6 is a newer numbering system that provides a much larger address pool than IPv4, among other features.

With less than 5% of IPv4 address space remaining, businesses and organizations will need IPv6 to support applications that require ongoing availability of contiguous IP addresses.

The counter on our home page provided by ARIN (American Registry for Internet Numbers) shows you just how many IPv4 addresses are left in the world right now. Yes, time is running out.

“We actually knew in 1994 that we had 15 to 20 years thanks to forecast models done by the Routing and Addressing (ROAD) group. It was this analysis that resulted in the IPng (now IPv6) initiative. We’re still right on track, and while there may have been folks saying to migrate earlier than needed, I agree … that now is definitely the time to start.”

John Curran-President and CEO
ARIN

Your GCN team is standing by to ensure that all of our clients’ Internet Service Providers are ready for the transition to IPv6.

IPv6 is specified by the Internet Engineering Task Force (IETF) and described in Internet standard document RFC 2460, which was published in December 1998.[1]

IPv6 Subnet Size Reference Table

Pv6 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 18,014,398,509,481,984
/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

IPv4 Subnet Size Reference Table

Pv4 CIDR Subnet Number of IPs
/4 268435456
/5 134217728
/6 67108864
/7 33554432
/8 16777216
/9 6388608
/10 4194304
/11 2097152
/12 1048576
/13 524288
/14 262144
/15 131072
/16 65536
/17 32768
/18 16384
/19 8192
/20 4096
/21 2048
/22 1024
/23 512
/24 256
/25 128
/26 64
/27 32
/28 16
/29 8
/30 4
/31 point-to-point links only
/32 1