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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Prefix/120
Addresses256
/64 networksPart of one
Network
2c19:dd:d9:dd:c25:c25:94de:3800/120
First address
2c19:dd:d9:dd:c25:c25:94de:3800
Last address
2c19:dd:d9:dd:c25:c25:94de:38ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:00d9:00dd:0c25:0c25:94de:3800
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
8.3.e.d.4.9.5.2.c.0.5.2.c.0.d.d.0.0.9.d.0.0.d.d.0.0.9.1.c.2.ip6.arpa
Split into smaller subnets/128
/121 (2)/122 (4)/123 (8)/124 (16)/127 (128)/128 (256)

2c19:dd:d9:dd:c25:c25:94de:3800/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:d9:dd:c25:c25:94de:3800/1282c19:dd:d9:dd:c25:c25:94de:3800
22c19:dd:d9:dd:c25:c25:94de:3801/1282c19:dd:d9:dd:c25:c25:94de:3801
32c19:dd:d9:dd:c25:c25:94de:3802/1282c19:dd:d9:dd:c25:c25:94de:3802
42c19:dd:d9:dd:c25:c25:94de:3803/1282c19:dd:d9:dd:c25:c25:94de:3803
52c19:dd:d9:dd:c25:c25:94de:3804/1282c19:dd:d9:dd:c25:c25:94de:3804
62c19:dd:d9:dd:c25:c25:94de:3805/1282c19:dd:d9:dd:c25:c25:94de:3805
72c19:dd:d9:dd:c25:c25:94de:3806/1282c19:dd:d9:dd:c25:c25:94de:3806
82c19:dd:d9:dd:c25:c25:94de:3807/1282c19:dd:d9:dd:c25:c25:94de:3807
92c19:dd:d9:dd:c25:c25:94de:3808/1282c19:dd:d9:dd:c25:c25:94de:3808
102c19:dd:d9:dd:c25:c25:94de:3809/1282c19:dd:d9:dd:c25:c25:94de:3809
112c19:dd:d9:dd:c25:c25:94de:380a/1282c19:dd:d9:dd:c25:c25:94de:380a
122c19:dd:d9:dd:c25:c25:94de:380b/1282c19:dd:d9:dd:c25:c25:94de:380b
132c19:dd:d9:dd:c25:c25:94de:380c/1282c19:dd:d9:dd:c25:c25:94de:380c
142c19:dd:d9:dd:c25:c25:94de:380d/1282c19:dd:d9:dd:c25:c25:94de:380d
152c19:dd:d9:dd:c25:c25:94de:380e/1282c19:dd:d9:dd:c25:c25:94de:380e
162c19:dd:d9:dd:c25:c25:94de:380f/1282c19:dd:d9:dd:c25:c25:94de:380f
172c19:dd:d9:dd:c25:c25:94de:3810/1282c19:dd:d9:dd:c25:c25:94de:3810
182c19:dd:d9:dd:c25:c25:94de:3811/1282c19:dd:d9:dd:c25:c25:94de:3811
192c19:dd:d9:dd:c25:c25:94de:3812/1282c19:dd:d9:dd:c25:c25:94de:3812
202c19:dd:d9:dd:c25:c25:94de:3813/1282c19:dd:d9:dd:c25:c25:94de:3813
212c19:dd:d9:dd:c25:c25:94de:3814/1282c19:dd:d9:dd:c25:c25:94de:3814
222c19:dd:d9:dd:c25:c25:94de:3815/1282c19:dd:d9:dd:c25:c25:94de:3815
232c19:dd:d9:dd:c25:c25:94de:3816/1282c19:dd:d9:dd:c25:c25:94de:3816
242c19:dd:d9:dd:c25:c25:94de:3817/1282c19:dd:d9:dd:c25:c25:94de:3817
252c19:dd:d9:dd:c25:c25:94de:3818/1282c19:dd:d9:dd:c25:c25:94de:3818
262c19:dd:d9:dd:c25:c25:94de:3819/1282c19:dd:d9:dd:c25:c25:94de:3819
272c19:dd:d9:dd:c25:c25:94de:381a/1282c19:dd:d9:dd:c25:c25:94de:381a
282c19:dd:d9:dd:c25:c25:94de:381b/1282c19:dd:d9:dd:c25:c25:94de:381b
292c19:dd:d9:dd:c25:c25:94de:381c/1282c19:dd:d9:dd:c25:c25:94de:381c
302c19:dd:d9:dd:c25:c25:94de:381d/1282c19:dd:d9:dd:c25:c25:94de:381d
312c19:dd:d9:dd:c25:c25:94de:381e/1282c19:dd:d9:dd:c25:c25:94de:381e
322c19:dd:d9:dd:c25:c25:94de:381f/1282c19:dd:d9:dd:c25:c25:94de:381f
332c19:dd:d9:dd:c25:c25:94de:3820/1282c19:dd:d9:dd:c25:c25:94de:3820
342c19:dd:d9:dd:c25:c25:94de:3821/1282c19:dd:d9:dd:c25:c25:94de:3821
352c19:dd:d9:dd:c25:c25:94de:3822/1282c19:dd:d9:dd:c25:c25:94de:3822
362c19:dd:d9:dd:c25:c25:94de:3823/1282c19:dd:d9:dd:c25:c25:94de:3823
372c19:dd:d9:dd:c25:c25:94de:3824/1282c19:dd:d9:dd:c25:c25:94de:3824
382c19:dd:d9:dd:c25:c25:94de:3825/1282c19:dd:d9:dd:c25:c25:94de:3825
392c19:dd:d9:dd:c25:c25:94de:3826/1282c19:dd:d9:dd:c25:c25:94de:3826
402c19:dd:d9:dd:c25:c25:94de:3827/1282c19:dd:d9:dd:c25:c25:94de:3827
412c19:dd:d9:dd:c25:c25:94de:3828/1282c19:dd:d9:dd:c25:c25:94de:3828
422c19:dd:d9:dd:c25:c25:94de:3829/1282c19:dd:d9:dd:c25:c25:94de:3829
432c19:dd:d9:dd:c25:c25:94de:382a/1282c19:dd:d9:dd:c25:c25:94de:382a
442c19:dd:d9:dd:c25:c25:94de:382b/1282c19:dd:d9:dd:c25:c25:94de:382b
452c19:dd:d9:dd:c25:c25:94de:382c/1282c19:dd:d9:dd:c25:c25:94de:382c
462c19:dd:d9:dd:c25:c25:94de:382d/1282c19:dd:d9:dd:c25:c25:94de:382d
472c19:dd:d9:dd:c25:c25:94de:382e/1282c19:dd:d9:dd:c25:c25:94de:382e
482c19:dd:d9:dd:c25:c25:94de:382f/1282c19:dd:d9:dd:c25:c25:94de:382f
492c19:dd:d9:dd:c25:c25:94de:3830/1282c19:dd:d9:dd:c25:c25:94de:3830
502c19:dd:d9:dd:c25:c25:94de:3831/1282c19:dd:d9:dd:c25:c25:94de:3831
512c19:dd:d9:dd:c25:c25:94de:3832/1282c19:dd:d9:dd:c25:c25:94de:3832
522c19:dd:d9:dd:c25:c25:94de:3833/1282c19:dd:d9:dd:c25:c25:94de:3833
532c19:dd:d9:dd:c25:c25:94de:3834/1282c19:dd:d9:dd:c25:c25:94de:3834
542c19:dd:d9:dd:c25:c25:94de:3835/1282c19:dd:d9:dd:c25:c25:94de:3835
552c19:dd:d9:dd:c25:c25:94de:3836/1282c19:dd:d9:dd:c25:c25:94de:3836
562c19:dd:d9:dd:c25:c25:94de:3837/1282c19:dd:d9:dd:c25:c25:94de:3837
572c19:dd:d9:dd:c25:c25:94de:3838/1282c19:dd:d9:dd:c25:c25:94de:3838
582c19:dd:d9:dd:c25:c25:94de:3839/1282c19:dd:d9:dd:c25:c25:94de:3839
592c19:dd:d9:dd:c25:c25:94de:383a/1282c19:dd:d9:dd:c25:c25:94de:383a
602c19:dd:d9:dd:c25:c25:94de:383b/1282c19:dd:d9:dd:c25:c25:94de:383b
612c19:dd:d9:dd:c25:c25:94de:383c/1282c19:dd:d9:dd:c25:c25:94de:383c
622c19:dd:d9:dd:c25:c25:94de:383d/1282c19:dd:d9:dd:c25:c25:94de:383d
632c19:dd:d9:dd:c25:c25:94de:383e/1282c19:dd:d9:dd:c25:c25:94de:383e
642c19:dd:d9:dd:c25:c25:94de:383f/1282c19:dd:d9:dd:c25:c25:94de:383f
652c19:dd:d9:dd:c25:c25:94de:3840/1282c19:dd:d9:dd:c25:c25:94de:3840
662c19:dd:d9:dd:c25:c25:94de:3841/1282c19:dd:d9:dd:c25:c25:94de:3841
672c19:dd:d9:dd:c25:c25:94de:3842/1282c19:dd:d9:dd:c25:c25:94de:3842
682c19:dd:d9:dd:c25:c25:94de:3843/1282c19:dd:d9:dd:c25:c25:94de:3843
692c19:dd:d9:dd:c25:c25:94de:3844/1282c19:dd:d9:dd:c25:c25:94de:3844
702c19:dd:d9:dd:c25:c25:94de:3845/1282c19:dd:d9:dd:c25:c25:94de:3845
712c19:dd:d9:dd:c25:c25:94de:3846/1282c19:dd:d9:dd:c25:c25:94de:3846
722c19:dd:d9:dd:c25:c25:94de:3847/1282c19:dd:d9:dd:c25:c25:94de:3847
732c19:dd:d9:dd:c25:c25:94de:3848/1282c19:dd:d9:dd:c25:c25:94de:3848
742c19:dd:d9:dd:c25:c25:94de:3849/1282c19:dd:d9:dd:c25:c25:94de:3849
752c19:dd:d9:dd:c25:c25:94de:384a/1282c19:dd:d9:dd:c25:c25:94de:384a
762c19:dd:d9:dd:c25:c25:94de:384b/1282c19:dd:d9:dd:c25:c25:94de:384b
772c19:dd:d9:dd:c25:c25:94de:384c/1282c19:dd:d9:dd:c25:c25:94de:384c
782c19:dd:d9:dd:c25:c25:94de:384d/1282c19:dd:d9:dd:c25:c25:94de:384d
792c19:dd:d9:dd:c25:c25:94de:384e/1282c19:dd:d9:dd:c25:c25:94de:384e
802c19:dd:d9:dd:c25:c25:94de:384f/1282c19:dd:d9:dd:c25:c25:94de:384f
812c19:dd:d9:dd:c25:c25:94de:3850/1282c19:dd:d9:dd:c25:c25:94de:3850
822c19:dd:d9:dd:c25:c25:94de:3851/1282c19:dd:d9:dd:c25:c25:94de:3851
832c19:dd:d9:dd:c25:c25:94de:3852/1282c19:dd:d9:dd:c25:c25:94de:3852
842c19:dd:d9:dd:c25:c25:94de:3853/1282c19:dd:d9:dd:c25:c25:94de:3853
852c19:dd:d9:dd:c25:c25:94de:3854/1282c19:dd:d9:dd:c25:c25:94de:3854
862c19:dd:d9:dd:c25:c25:94de:3855/1282c19:dd:d9:dd:c25:c25:94de:3855
872c19:dd:d9:dd:c25:c25:94de:3856/1282c19:dd:d9:dd:c25:c25:94de:3856
882c19:dd:d9:dd:c25:c25:94de:3857/1282c19:dd:d9:dd:c25:c25:94de:3857
892c19:dd:d9:dd:c25:c25:94de:3858/1282c19:dd:d9:dd:c25:c25:94de:3858
902c19:dd:d9:dd:c25:c25:94de:3859/1282c19:dd:d9:dd:c25:c25:94de:3859
912c19:dd:d9:dd:c25:c25:94de:385a/1282c19:dd:d9:dd:c25:c25:94de:385a
922c19:dd:d9:dd:c25:c25:94de:385b/1282c19:dd:d9:dd:c25:c25:94de:385b
932c19:dd:d9:dd:c25:c25:94de:385c/1282c19:dd:d9:dd:c25:c25:94de:385c
942c19:dd:d9:dd:c25:c25:94de:385d/1282c19:dd:d9:dd:c25:c25:94de:385d
952c19:dd:d9:dd:c25:c25:94de:385e/1282c19:dd:d9:dd:c25:c25:94de:385e
962c19:dd:d9:dd:c25:c25:94de:385f/1282c19:dd:d9:dd:c25:c25:94de:385f
972c19:dd:d9:dd:c25:c25:94de:3860/1282c19:dd:d9:dd:c25:c25:94de:3860
982c19:dd:d9:dd:c25:c25:94de:3861/1282c19:dd:d9:dd:c25:c25:94de:3861
992c19:dd:d9:dd:c25:c25:94de:3862/1282c19:dd:d9:dd:c25:c25:94de:3862
1002c19:dd:d9:dd:c25:c25:94de:3863/1282c19:dd:d9:dd:c25:c25:94de:3863
1012c19:dd:d9:dd:c25:c25:94de:3864/1282c19:dd:d9:dd:c25:c25:94de:3864
1022c19:dd:d9:dd:c25:c25:94de:3865/1282c19:dd:d9:dd:c25:c25:94de:3865
1032c19:dd:d9:dd:c25:c25:94de:3866/1282c19:dd:d9:dd:c25:c25:94de:3866
1042c19:dd:d9:dd:c25:c25:94de:3867/1282c19:dd:d9:dd:c25:c25:94de:3867
1052c19:dd:d9:dd:c25:c25:94de:3868/1282c19:dd:d9:dd:c25:c25:94de:3868
1062c19:dd:d9:dd:c25:c25:94de:3869/1282c19:dd:d9:dd:c25:c25:94de:3869
1072c19:dd:d9:dd:c25:c25:94de:386a/1282c19:dd:d9:dd:c25:c25:94de:386a
1082c19:dd:d9:dd:c25:c25:94de:386b/1282c19:dd:d9:dd:c25:c25:94de:386b
1092c19:dd:d9:dd:c25:c25:94de:386c/1282c19:dd:d9:dd:c25:c25:94de:386c
1102c19:dd:d9:dd:c25:c25:94de:386d/1282c19:dd:d9:dd:c25:c25:94de:386d
1112c19:dd:d9:dd:c25:c25:94de:386e/1282c19:dd:d9:dd:c25:c25:94de:386e
1122c19:dd:d9:dd:c25:c25:94de:386f/1282c19:dd:d9:dd:c25:c25:94de:386f
1132c19:dd:d9:dd:c25:c25:94de:3870/1282c19:dd:d9:dd:c25:c25:94de:3870
1142c19:dd:d9:dd:c25:c25:94de:3871/1282c19:dd:d9:dd:c25:c25:94de:3871
1152c19:dd:d9:dd:c25:c25:94de:3872/1282c19:dd:d9:dd:c25:c25:94de:3872
1162c19:dd:d9:dd:c25:c25:94de:3873/1282c19:dd:d9:dd:c25:c25:94de:3873
1172c19:dd:d9:dd:c25:c25:94de:3874/1282c19:dd:d9:dd:c25:c25:94de:3874
1182c19:dd:d9:dd:c25:c25:94de:3875/1282c19:dd:d9:dd:c25:c25:94de:3875
1192c19:dd:d9:dd:c25:c25:94de:3876/1282c19:dd:d9:dd:c25:c25:94de:3876
1202c19:dd:d9:dd:c25:c25:94de:3877/1282c19:dd:d9:dd:c25:c25:94de:3877
1212c19:dd:d9:dd:c25:c25:94de:3878/1282c19:dd:d9:dd:c25:c25:94de:3878
1222c19:dd:d9:dd:c25:c25:94de:3879/1282c19:dd:d9:dd:c25:c25:94de:3879
1232c19:dd:d9:dd:c25:c25:94de:387a/1282c19:dd:d9:dd:c25:c25:94de:387a
1242c19:dd:d9:dd:c25:c25:94de:387b/1282c19:dd:d9:dd:c25:c25:94de:387b
1252c19:dd:d9:dd:c25:c25:94de:387c/1282c19:dd:d9:dd:c25:c25:94de:387c
1262c19:dd:d9:dd:c25:c25:94de:387d/1282c19:dd:d9:dd:c25:c25:94de:387d
1272c19:dd:d9:dd:c25:c25:94de:387e/1282c19:dd:d9:dd:c25:c25:94de:387e
1282c19:dd:d9:dd:c25:c25:94de:387f/1282c19:dd:d9:dd:c25:c25:94de:387f
1292c19:dd:d9:dd:c25:c25:94de:3880/1282c19:dd:d9:dd:c25:c25:94de:3880
1302c19:dd:d9:dd:c25:c25:94de:3881/1282c19:dd:d9:dd:c25:c25:94de:3881
1312c19:dd:d9:dd:c25:c25:94de:3882/1282c19:dd:d9:dd:c25:c25:94de:3882
1322c19:dd:d9:dd:c25:c25:94de:3883/1282c19:dd:d9:dd:c25:c25:94de:3883
1332c19:dd:d9:dd:c25:c25:94de:3884/1282c19:dd:d9:dd:c25:c25:94de:3884
1342c19:dd:d9:dd:c25:c25:94de:3885/1282c19:dd:d9:dd:c25:c25:94de:3885
1352c19:dd:d9:dd:c25:c25:94de:3886/1282c19:dd:d9:dd:c25:c25:94de:3886
1362c19:dd:d9:dd:c25:c25:94de:3887/1282c19:dd:d9:dd:c25:c25:94de:3887
1372c19:dd:d9:dd:c25:c25:94de:3888/1282c19:dd:d9:dd:c25:c25:94de:3888
1382c19:dd:d9:dd:c25:c25:94de:3889/1282c19:dd:d9:dd:c25:c25:94de:3889
1392c19:dd:d9:dd:c25:c25:94de:388a/1282c19:dd:d9:dd:c25:c25:94de:388a
1402c19:dd:d9:dd:c25:c25:94de:388b/1282c19:dd:d9:dd:c25:c25:94de:388b
1412c19:dd:d9:dd:c25:c25:94de:388c/1282c19:dd:d9:dd:c25:c25:94de:388c
1422c19:dd:d9:dd:c25:c25:94de:388d/1282c19:dd:d9:dd:c25:c25:94de:388d
1432c19:dd:d9:dd:c25:c25:94de:388e/1282c19:dd:d9:dd:c25:c25:94de:388e
1442c19:dd:d9:dd:c25:c25:94de:388f/1282c19:dd:d9:dd:c25:c25:94de:388f
1452c19:dd:d9:dd:c25:c25:94de:3890/1282c19:dd:d9:dd:c25:c25:94de:3890
1462c19:dd:d9:dd:c25:c25:94de:3891/1282c19:dd:d9:dd:c25:c25:94de:3891
1472c19:dd:d9:dd:c25:c25:94de:3892/1282c19:dd:d9:dd:c25:c25:94de:3892
1482c19:dd:d9:dd:c25:c25:94de:3893/1282c19:dd:d9:dd:c25:c25:94de:3893
1492c19:dd:d9:dd:c25:c25:94de:3894/1282c19:dd:d9:dd:c25:c25:94de:3894
1502c19:dd:d9:dd:c25:c25:94de:3895/1282c19:dd:d9:dd:c25:c25:94de:3895
1512c19:dd:d9:dd:c25:c25:94de:3896/1282c19:dd:d9:dd:c25:c25:94de:3896
1522c19:dd:d9:dd:c25:c25:94de:3897/1282c19:dd:d9:dd:c25:c25:94de:3897
1532c19:dd:d9:dd:c25:c25:94de:3898/1282c19:dd:d9:dd:c25:c25:94de:3898
1542c19:dd:d9:dd:c25:c25:94de:3899/1282c19:dd:d9:dd:c25:c25:94de:3899
1552c19:dd:d9:dd:c25:c25:94de:389a/1282c19:dd:d9:dd:c25:c25:94de:389a
1562c19:dd:d9:dd:c25:c25:94de:389b/1282c19:dd:d9:dd:c25:c25:94de:389b
1572c19:dd:d9:dd:c25:c25:94de:389c/1282c19:dd:d9:dd:c25:c25:94de:389c
1582c19:dd:d9:dd:c25:c25:94de:389d/1282c19:dd:d9:dd:c25:c25:94de:389d
1592c19:dd:d9:dd:c25:c25:94de:389e/1282c19:dd:d9:dd:c25:c25:94de:389e
1602c19:dd:d9:dd:c25:c25:94de:389f/1282c19:dd:d9:dd:c25:c25:94de:389f
1612c19:dd:d9:dd:c25:c25:94de:38a0/1282c19:dd:d9:dd:c25:c25:94de:38a0
1622c19:dd:d9:dd:c25:c25:94de:38a1/1282c19:dd:d9:dd:c25:c25:94de:38a1
1632c19:dd:d9:dd:c25:c25:94de:38a2/1282c19:dd:d9:dd:c25:c25:94de:38a2
1642c19:dd:d9:dd:c25:c25:94de:38a3/1282c19:dd:d9:dd:c25:c25:94de:38a3
1652c19:dd:d9:dd:c25:c25:94de:38a4/1282c19:dd:d9:dd:c25:c25:94de:38a4
1662c19:dd:d9:dd:c25:c25:94de:38a5/1282c19:dd:d9:dd:c25:c25:94de:38a5
1672c19:dd:d9:dd:c25:c25:94de:38a6/1282c19:dd:d9:dd:c25:c25:94de:38a6
1682c19:dd:d9:dd:c25:c25:94de:38a7/1282c19:dd:d9:dd:c25:c25:94de:38a7
1692c19:dd:d9:dd:c25:c25:94de:38a8/1282c19:dd:d9:dd:c25:c25:94de:38a8
1702c19:dd:d9:dd:c25:c25:94de:38a9/1282c19:dd:d9:dd:c25:c25:94de:38a9
1712c19:dd:d9:dd:c25:c25:94de:38aa/1282c19:dd:d9:dd:c25:c25:94de:38aa
1722c19:dd:d9:dd:c25:c25:94de:38ab/1282c19:dd:d9:dd:c25:c25:94de:38ab
1732c19:dd:d9:dd:c25:c25:94de:38ac/1282c19:dd:d9:dd:c25:c25:94de:38ac
1742c19:dd:d9:dd:c25:c25:94de:38ad/1282c19:dd:d9:dd:c25:c25:94de:38ad
1752c19:dd:d9:dd:c25:c25:94de:38ae/1282c19:dd:d9:dd:c25:c25:94de:38ae
1762c19:dd:d9:dd:c25:c25:94de:38af/1282c19:dd:d9:dd:c25:c25:94de:38af
1772c19:dd:d9:dd:c25:c25:94de:38b0/1282c19:dd:d9:dd:c25:c25:94de:38b0
1782c19:dd:d9:dd:c25:c25:94de:38b1/1282c19:dd:d9:dd:c25:c25:94de:38b1
1792c19:dd:d9:dd:c25:c25:94de:38b2/1282c19:dd:d9:dd:c25:c25:94de:38b2
1802c19:dd:d9:dd:c25:c25:94de:38b3/1282c19:dd:d9:dd:c25:c25:94de:38b3
1812c19:dd:d9:dd:c25:c25:94de:38b4/1282c19:dd:d9:dd:c25:c25:94de:38b4
1822c19:dd:d9:dd:c25:c25:94de:38b5/1282c19:dd:d9:dd:c25:c25:94de:38b5
1832c19:dd:d9:dd:c25:c25:94de:38b6/1282c19:dd:d9:dd:c25:c25:94de:38b6
1842c19:dd:d9:dd:c25:c25:94de:38b7/1282c19:dd:d9:dd:c25:c25:94de:38b7
1852c19:dd:d9:dd:c25:c25:94de:38b8/1282c19:dd:d9:dd:c25:c25:94de:38b8
1862c19:dd:d9:dd:c25:c25:94de:38b9/1282c19:dd:d9:dd:c25:c25:94de:38b9
1872c19:dd:d9:dd:c25:c25:94de:38ba/1282c19:dd:d9:dd:c25:c25:94de:38ba
1882c19:dd:d9:dd:c25:c25:94de:38bb/1282c19:dd:d9:dd:c25:c25:94de:38bb
1892c19:dd:d9:dd:c25:c25:94de:38bc/1282c19:dd:d9:dd:c25:c25:94de:38bc
1902c19:dd:d9:dd:c25:c25:94de:38bd/1282c19:dd:d9:dd:c25:c25:94de:38bd
1912c19:dd:d9:dd:c25:c25:94de:38be/1282c19:dd:d9:dd:c25:c25:94de:38be
1922c19:dd:d9:dd:c25:c25:94de:38bf/1282c19:dd:d9:dd:c25:c25:94de:38bf
1932c19:dd:d9:dd:c25:c25:94de:38c0/1282c19:dd:d9:dd:c25:c25:94de:38c0
1942c19:dd:d9:dd:c25:c25:94de:38c1/1282c19:dd:d9:dd:c25:c25:94de:38c1
1952c19:dd:d9:dd:c25:c25:94de:38c2/1282c19:dd:d9:dd:c25:c25:94de:38c2
1962c19:dd:d9:dd:c25:c25:94de:38c3/1282c19:dd:d9:dd:c25:c25:94de:38c3
1972c19:dd:d9:dd:c25:c25:94de:38c4/1282c19:dd:d9:dd:c25:c25:94de:38c4
1982c19:dd:d9:dd:c25:c25:94de:38c5/1282c19:dd:d9:dd:c25:c25:94de:38c5
1992c19:dd:d9:dd:c25:c25:94de:38c6/1282c19:dd:d9:dd:c25:c25:94de:38c6
2002c19:dd:d9:dd:c25:c25:94de:38c7/1282c19:dd:d9:dd:c25:c25:94de:38c7
2012c19:dd:d9:dd:c25:c25:94de:38c8/1282c19:dd:d9:dd:c25:c25:94de:38c8
2022c19:dd:d9:dd:c25:c25:94de:38c9/1282c19:dd:d9:dd:c25:c25:94de:38c9
2032c19:dd:d9:dd:c25:c25:94de:38ca/1282c19:dd:d9:dd:c25:c25:94de:38ca
2042c19:dd:d9:dd:c25:c25:94de:38cb/1282c19:dd:d9:dd:c25:c25:94de:38cb
2052c19:dd:d9:dd:c25:c25:94de:38cc/1282c19:dd:d9:dd:c25:c25:94de:38cc
2062c19:dd:d9:dd:c25:c25:94de:38cd/1282c19:dd:d9:dd:c25:c25:94de:38cd
2072c19:dd:d9:dd:c25:c25:94de:38ce/1282c19:dd:d9:dd:c25:c25:94de:38ce
2082c19:dd:d9:dd:c25:c25:94de:38cf/1282c19:dd:d9:dd:c25:c25:94de:38cf
2092c19:dd:d9:dd:c25:c25:94de:38d0/1282c19:dd:d9:dd:c25:c25:94de:38d0
2102c19:dd:d9:dd:c25:c25:94de:38d1/1282c19:dd:d9:dd:c25:c25:94de:38d1
2112c19:dd:d9:dd:c25:c25:94de:38d2/1282c19:dd:d9:dd:c25:c25:94de:38d2
2122c19:dd:d9:dd:c25:c25:94de:38d3/1282c19:dd:d9:dd:c25:c25:94de:38d3
2132c19:dd:d9:dd:c25:c25:94de:38d4/1282c19:dd:d9:dd:c25:c25:94de:38d4
2142c19:dd:d9:dd:c25:c25:94de:38d5/1282c19:dd:d9:dd:c25:c25:94de:38d5
2152c19:dd:d9:dd:c25:c25:94de:38d6/1282c19:dd:d9:dd:c25:c25:94de:38d6
2162c19:dd:d9:dd:c25:c25:94de:38d7/1282c19:dd:d9:dd:c25:c25:94de:38d7
2172c19:dd:d9:dd:c25:c25:94de:38d8/1282c19:dd:d9:dd:c25:c25:94de:38d8
2182c19:dd:d9:dd:c25:c25:94de:38d9/1282c19:dd:d9:dd:c25:c25:94de:38d9
2192c19:dd:d9:dd:c25:c25:94de:38da/1282c19:dd:d9:dd:c25:c25:94de:38da
2202c19:dd:d9:dd:c25:c25:94de:38db/1282c19:dd:d9:dd:c25:c25:94de:38db
2212c19:dd:d9:dd:c25:c25:94de:38dc/1282c19:dd:d9:dd:c25:c25:94de:38dc
2222c19:dd:d9:dd:c25:c25:94de:38dd/1282c19:dd:d9:dd:c25:c25:94de:38dd
2232c19:dd:d9:dd:c25:c25:94de:38de/1282c19:dd:d9:dd:c25:c25:94de:38de
2242c19:dd:d9:dd:c25:c25:94de:38df/1282c19:dd:d9:dd:c25:c25:94de:38df
2252c19:dd:d9:dd:c25:c25:94de:38e0/1282c19:dd:d9:dd:c25:c25:94de:38e0
2262c19:dd:d9:dd:c25:c25:94de:38e1/1282c19:dd:d9:dd:c25:c25:94de:38e1
2272c19:dd:d9:dd:c25:c25:94de:38e2/1282c19:dd:d9:dd:c25:c25:94de:38e2
2282c19:dd:d9:dd:c25:c25:94de:38e3/1282c19:dd:d9:dd:c25:c25:94de:38e3
2292c19:dd:d9:dd:c25:c25:94de:38e4/1282c19:dd:d9:dd:c25:c25:94de:38e4
2302c19:dd:d9:dd:c25:c25:94de:38e5/1282c19:dd:d9:dd:c25:c25:94de:38e5
2312c19:dd:d9:dd:c25:c25:94de:38e6/1282c19:dd:d9:dd:c25:c25:94de:38e6
2322c19:dd:d9:dd:c25:c25:94de:38e7/1282c19:dd:d9:dd:c25:c25:94de:38e7
2332c19:dd:d9:dd:c25:c25:94de:38e8/1282c19:dd:d9:dd:c25:c25:94de:38e8
2342c19:dd:d9:dd:c25:c25:94de:38e9/1282c19:dd:d9:dd:c25:c25:94de:38e9
2352c19:dd:d9:dd:c25:c25:94de:38ea/1282c19:dd:d9:dd:c25:c25:94de:38ea
2362c19:dd:d9:dd:c25:c25:94de:38eb/1282c19:dd:d9:dd:c25:c25:94de:38eb
2372c19:dd:d9:dd:c25:c25:94de:38ec/1282c19:dd:d9:dd:c25:c25:94de:38ec
2382c19:dd:d9:dd:c25:c25:94de:38ed/1282c19:dd:d9:dd:c25:c25:94de:38ed
2392c19:dd:d9:dd:c25:c25:94de:38ee/1282c19:dd:d9:dd:c25:c25:94de:38ee
2402c19:dd:d9:dd:c25:c25:94de:38ef/1282c19:dd:d9:dd:c25:c25:94de:38ef
2412c19:dd:d9:dd:c25:c25:94de:38f0/1282c19:dd:d9:dd:c25:c25:94de:38f0
2422c19:dd:d9:dd:c25:c25:94de:38f1/1282c19:dd:d9:dd:c25:c25:94de:38f1
2432c19:dd:d9:dd:c25:c25:94de:38f2/1282c19:dd:d9:dd:c25:c25:94de:38f2
2442c19:dd:d9:dd:c25:c25:94de:38f3/1282c19:dd:d9:dd:c25:c25:94de:38f3
2452c19:dd:d9:dd:c25:c25:94de:38f4/1282c19:dd:d9:dd:c25:c25:94de:38f4
2462c19:dd:d9:dd:c25:c25:94de:38f5/1282c19:dd:d9:dd:c25:c25:94de:38f5
2472c19:dd:d9:dd:c25:c25:94de:38f6/1282c19:dd:d9:dd:c25:c25:94de:38f6
2482c19:dd:d9:dd:c25:c25:94de:38f7/1282c19:dd:d9:dd:c25:c25:94de:38f7
2492c19:dd:d9:dd:c25:c25:94de:38f8/1282c19:dd:d9:dd:c25:c25:94de:38f8
2502c19:dd:d9:dd:c25:c25:94de:38f9/1282c19:dd:d9:dd:c25:c25:94de:38f9
2512c19:dd:d9:dd:c25:c25:94de:38fa/1282c19:dd:d9:dd:c25:c25:94de:38fa
2522c19:dd:d9:dd:c25:c25:94de:38fb/1282c19:dd:d9:dd:c25:c25:94de:38fb
2532c19:dd:d9:dd:c25:c25:94de:38fc/1282c19:dd:d9:dd:c25:c25:94de:38fc
2542c19:dd:d9:dd:c25:c25:94de:38fd/1282c19:dd:d9:dd:c25:c25:94de:38fd
2552c19:dd:d9:dd:c25:c25:94de:38fe/1282c19:dd:d9:dd:c25:c25:94de:38fe
2562c19:dd:d9:dd:c25:c25:94de:38ff/1282c19:dd:d9:dd:c25:c25:94de:38ff

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.