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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:3700/120
First address
2c19:dd:d9:dd:c25:c25:94de:3700
Last address
2c19:dd:d9:dd:c25:c25:94de:37ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:00d9:00dd:0c25:0c25:94de:3700
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
7.3.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:3700/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:d9:dd:c25:c25:94de:3700/1282c19:dd:d9:dd:c25:c25:94de:3700
22c19:dd:d9:dd:c25:c25:94de:3701/1282c19:dd:d9:dd:c25:c25:94de:3701
32c19:dd:d9:dd:c25:c25:94de:3702/1282c19:dd:d9:dd:c25:c25:94de:3702
42c19:dd:d9:dd:c25:c25:94de:3703/1282c19:dd:d9:dd:c25:c25:94de:3703
52c19:dd:d9:dd:c25:c25:94de:3704/1282c19:dd:d9:dd:c25:c25:94de:3704
62c19:dd:d9:dd:c25:c25:94de:3705/1282c19:dd:d9:dd:c25:c25:94de:3705
72c19:dd:d9:dd:c25:c25:94de:3706/1282c19:dd:d9:dd:c25:c25:94de:3706
82c19:dd:d9:dd:c25:c25:94de:3707/1282c19:dd:d9:dd:c25:c25:94de:3707
92c19:dd:d9:dd:c25:c25:94de:3708/1282c19:dd:d9:dd:c25:c25:94de:3708
102c19:dd:d9:dd:c25:c25:94de:3709/1282c19:dd:d9:dd:c25:c25:94de:3709
112c19:dd:d9:dd:c25:c25:94de:370a/1282c19:dd:d9:dd:c25:c25:94de:370a
122c19:dd:d9:dd:c25:c25:94de:370b/1282c19:dd:d9:dd:c25:c25:94de:370b
132c19:dd:d9:dd:c25:c25:94de:370c/1282c19:dd:d9:dd:c25:c25:94de:370c
142c19:dd:d9:dd:c25:c25:94de:370d/1282c19:dd:d9:dd:c25:c25:94de:370d
152c19:dd:d9:dd:c25:c25:94de:370e/1282c19:dd:d9:dd:c25:c25:94de:370e
162c19:dd:d9:dd:c25:c25:94de:370f/1282c19:dd:d9:dd:c25:c25:94de:370f
172c19:dd:d9:dd:c25:c25:94de:3710/1282c19:dd:d9:dd:c25:c25:94de:3710
182c19:dd:d9:dd:c25:c25:94de:3711/1282c19:dd:d9:dd:c25:c25:94de:3711
192c19:dd:d9:dd:c25:c25:94de:3712/1282c19:dd:d9:dd:c25:c25:94de:3712
202c19:dd:d9:dd:c25:c25:94de:3713/1282c19:dd:d9:dd:c25:c25:94de:3713
212c19:dd:d9:dd:c25:c25:94de:3714/1282c19:dd:d9:dd:c25:c25:94de:3714
222c19:dd:d9:dd:c25:c25:94de:3715/1282c19:dd:d9:dd:c25:c25:94de:3715
232c19:dd:d9:dd:c25:c25:94de:3716/1282c19:dd:d9:dd:c25:c25:94de:3716
242c19:dd:d9:dd:c25:c25:94de:3717/1282c19:dd:d9:dd:c25:c25:94de:3717
252c19:dd:d9:dd:c25:c25:94de:3718/1282c19:dd:d9:dd:c25:c25:94de:3718
262c19:dd:d9:dd:c25:c25:94de:3719/1282c19:dd:d9:dd:c25:c25:94de:3719
272c19:dd:d9:dd:c25:c25:94de:371a/1282c19:dd:d9:dd:c25:c25:94de:371a
282c19:dd:d9:dd:c25:c25:94de:371b/1282c19:dd:d9:dd:c25:c25:94de:371b
292c19:dd:d9:dd:c25:c25:94de:371c/1282c19:dd:d9:dd:c25:c25:94de:371c
302c19:dd:d9:dd:c25:c25:94de:371d/1282c19:dd:d9:dd:c25:c25:94de:371d
312c19:dd:d9:dd:c25:c25:94de:371e/1282c19:dd:d9:dd:c25:c25:94de:371e
322c19:dd:d9:dd:c25:c25:94de:371f/1282c19:dd:d9:dd:c25:c25:94de:371f
332c19:dd:d9:dd:c25:c25:94de:3720/1282c19:dd:d9:dd:c25:c25:94de:3720
342c19:dd:d9:dd:c25:c25:94de:3721/1282c19:dd:d9:dd:c25:c25:94de:3721
352c19:dd:d9:dd:c25:c25:94de:3722/1282c19:dd:d9:dd:c25:c25:94de:3722
362c19:dd:d9:dd:c25:c25:94de:3723/1282c19:dd:d9:dd:c25:c25:94de:3723
372c19:dd:d9:dd:c25:c25:94de:3724/1282c19:dd:d9:dd:c25:c25:94de:3724
382c19:dd:d9:dd:c25:c25:94de:3725/1282c19:dd:d9:dd:c25:c25:94de:3725
392c19:dd:d9:dd:c25:c25:94de:3726/1282c19:dd:d9:dd:c25:c25:94de:3726
402c19:dd:d9:dd:c25:c25:94de:3727/1282c19:dd:d9:dd:c25:c25:94de:3727
412c19:dd:d9:dd:c25:c25:94de:3728/1282c19:dd:d9:dd:c25:c25:94de:3728
422c19:dd:d9:dd:c25:c25:94de:3729/1282c19:dd:d9:dd:c25:c25:94de:3729
432c19:dd:d9:dd:c25:c25:94de:372a/1282c19:dd:d9:dd:c25:c25:94de:372a
442c19:dd:d9:dd:c25:c25:94de:372b/1282c19:dd:d9:dd:c25:c25:94de:372b
452c19:dd:d9:dd:c25:c25:94de:372c/1282c19:dd:d9:dd:c25:c25:94de:372c
462c19:dd:d9:dd:c25:c25:94de:372d/1282c19:dd:d9:dd:c25:c25:94de:372d
472c19:dd:d9:dd:c25:c25:94de:372e/1282c19:dd:d9:dd:c25:c25:94de:372e
482c19:dd:d9:dd:c25:c25:94de:372f/1282c19:dd:d9:dd:c25:c25:94de:372f
492c19:dd:d9:dd:c25:c25:94de:3730/1282c19:dd:d9:dd:c25:c25:94de:3730
502c19:dd:d9:dd:c25:c25:94de:3731/1282c19:dd:d9:dd:c25:c25:94de:3731
512c19:dd:d9:dd:c25:c25:94de:3732/1282c19:dd:d9:dd:c25:c25:94de:3732
522c19:dd:d9:dd:c25:c25:94de:3733/1282c19:dd:d9:dd:c25:c25:94de:3733
532c19:dd:d9:dd:c25:c25:94de:3734/1282c19:dd:d9:dd:c25:c25:94de:3734
542c19:dd:d9:dd:c25:c25:94de:3735/1282c19:dd:d9:dd:c25:c25:94de:3735
552c19:dd:d9:dd:c25:c25:94de:3736/1282c19:dd:d9:dd:c25:c25:94de:3736
562c19:dd:d9:dd:c25:c25:94de:3737/1282c19:dd:d9:dd:c25:c25:94de:3737
572c19:dd:d9:dd:c25:c25:94de:3738/1282c19:dd:d9:dd:c25:c25:94de:3738
582c19:dd:d9:dd:c25:c25:94de:3739/1282c19:dd:d9:dd:c25:c25:94de:3739
592c19:dd:d9:dd:c25:c25:94de:373a/1282c19:dd:d9:dd:c25:c25:94de:373a
602c19:dd:d9:dd:c25:c25:94de:373b/1282c19:dd:d9:dd:c25:c25:94de:373b
612c19:dd:d9:dd:c25:c25:94de:373c/1282c19:dd:d9:dd:c25:c25:94de:373c
622c19:dd:d9:dd:c25:c25:94de:373d/1282c19:dd:d9:dd:c25:c25:94de:373d
632c19:dd:d9:dd:c25:c25:94de:373e/1282c19:dd:d9:dd:c25:c25:94de:373e
642c19:dd:d9:dd:c25:c25:94de:373f/1282c19:dd:d9:dd:c25:c25:94de:373f
652c19:dd:d9:dd:c25:c25:94de:3740/1282c19:dd:d9:dd:c25:c25:94de:3740
662c19:dd:d9:dd:c25:c25:94de:3741/1282c19:dd:d9:dd:c25:c25:94de:3741
672c19:dd:d9:dd:c25:c25:94de:3742/1282c19:dd:d9:dd:c25:c25:94de:3742
682c19:dd:d9:dd:c25:c25:94de:3743/1282c19:dd:d9:dd:c25:c25:94de:3743
692c19:dd:d9:dd:c25:c25:94de:3744/1282c19:dd:d9:dd:c25:c25:94de:3744
702c19:dd:d9:dd:c25:c25:94de:3745/1282c19:dd:d9:dd:c25:c25:94de:3745
712c19:dd:d9:dd:c25:c25:94de:3746/1282c19:dd:d9:dd:c25:c25:94de:3746
722c19:dd:d9:dd:c25:c25:94de:3747/1282c19:dd:d9:dd:c25:c25:94de:3747
732c19:dd:d9:dd:c25:c25:94de:3748/1282c19:dd:d9:dd:c25:c25:94de:3748
742c19:dd:d9:dd:c25:c25:94de:3749/1282c19:dd:d9:dd:c25:c25:94de:3749
752c19:dd:d9:dd:c25:c25:94de:374a/1282c19:dd:d9:dd:c25:c25:94de:374a
762c19:dd:d9:dd:c25:c25:94de:374b/1282c19:dd:d9:dd:c25:c25:94de:374b
772c19:dd:d9:dd:c25:c25:94de:374c/1282c19:dd:d9:dd:c25:c25:94de:374c
782c19:dd:d9:dd:c25:c25:94de:374d/1282c19:dd:d9:dd:c25:c25:94de:374d
792c19:dd:d9:dd:c25:c25:94de:374e/1282c19:dd:d9:dd:c25:c25:94de:374e
802c19:dd:d9:dd:c25:c25:94de:374f/1282c19:dd:d9:dd:c25:c25:94de:374f
812c19:dd:d9:dd:c25:c25:94de:3750/1282c19:dd:d9:dd:c25:c25:94de:3750
822c19:dd:d9:dd:c25:c25:94de:3751/1282c19:dd:d9:dd:c25:c25:94de:3751
832c19:dd:d9:dd:c25:c25:94de:3752/1282c19:dd:d9:dd:c25:c25:94de:3752
842c19:dd:d9:dd:c25:c25:94de:3753/1282c19:dd:d9:dd:c25:c25:94de:3753
852c19:dd:d9:dd:c25:c25:94de:3754/1282c19:dd:d9:dd:c25:c25:94de:3754
862c19:dd:d9:dd:c25:c25:94de:3755/1282c19:dd:d9:dd:c25:c25:94de:3755
872c19:dd:d9:dd:c25:c25:94de:3756/1282c19:dd:d9:dd:c25:c25:94de:3756
882c19:dd:d9:dd:c25:c25:94de:3757/1282c19:dd:d9:dd:c25:c25:94de:3757
892c19:dd:d9:dd:c25:c25:94de:3758/1282c19:dd:d9:dd:c25:c25:94de:3758
902c19:dd:d9:dd:c25:c25:94de:3759/1282c19:dd:d9:dd:c25:c25:94de:3759
912c19:dd:d9:dd:c25:c25:94de:375a/1282c19:dd:d9:dd:c25:c25:94de:375a
922c19:dd:d9:dd:c25:c25:94de:375b/1282c19:dd:d9:dd:c25:c25:94de:375b
932c19:dd:d9:dd:c25:c25:94de:375c/1282c19:dd:d9:dd:c25:c25:94de:375c
942c19:dd:d9:dd:c25:c25:94de:375d/1282c19:dd:d9:dd:c25:c25:94de:375d
952c19:dd:d9:dd:c25:c25:94de:375e/1282c19:dd:d9:dd:c25:c25:94de:375e
962c19:dd:d9:dd:c25:c25:94de:375f/1282c19:dd:d9:dd:c25:c25:94de:375f
972c19:dd:d9:dd:c25:c25:94de:3760/1282c19:dd:d9:dd:c25:c25:94de:3760
982c19:dd:d9:dd:c25:c25:94de:3761/1282c19:dd:d9:dd:c25:c25:94de:3761
992c19:dd:d9:dd:c25:c25:94de:3762/1282c19:dd:d9:dd:c25:c25:94de:3762
1002c19:dd:d9:dd:c25:c25:94de:3763/1282c19:dd:d9:dd:c25:c25:94de:3763
1012c19:dd:d9:dd:c25:c25:94de:3764/1282c19:dd:d9:dd:c25:c25:94de:3764
1022c19:dd:d9:dd:c25:c25:94de:3765/1282c19:dd:d9:dd:c25:c25:94de:3765
1032c19:dd:d9:dd:c25:c25:94de:3766/1282c19:dd:d9:dd:c25:c25:94de:3766
1042c19:dd:d9:dd:c25:c25:94de:3767/1282c19:dd:d9:dd:c25:c25:94de:3767
1052c19:dd:d9:dd:c25:c25:94de:3768/1282c19:dd:d9:dd:c25:c25:94de:3768
1062c19:dd:d9:dd:c25:c25:94de:3769/1282c19:dd:d9:dd:c25:c25:94de:3769
1072c19:dd:d9:dd:c25:c25:94de:376a/1282c19:dd:d9:dd:c25:c25:94de:376a
1082c19:dd:d9:dd:c25:c25:94de:376b/1282c19:dd:d9:dd:c25:c25:94de:376b
1092c19:dd:d9:dd:c25:c25:94de:376c/1282c19:dd:d9:dd:c25:c25:94de:376c
1102c19:dd:d9:dd:c25:c25:94de:376d/1282c19:dd:d9:dd:c25:c25:94de:376d
1112c19:dd:d9:dd:c25:c25:94de:376e/1282c19:dd:d9:dd:c25:c25:94de:376e
1122c19:dd:d9:dd:c25:c25:94de:376f/1282c19:dd:d9:dd:c25:c25:94de:376f
1132c19:dd:d9:dd:c25:c25:94de:3770/1282c19:dd:d9:dd:c25:c25:94de:3770
1142c19:dd:d9:dd:c25:c25:94de:3771/1282c19:dd:d9:dd:c25:c25:94de:3771
1152c19:dd:d9:dd:c25:c25:94de:3772/1282c19:dd:d9:dd:c25:c25:94de:3772
1162c19:dd:d9:dd:c25:c25:94de:3773/1282c19:dd:d9:dd:c25:c25:94de:3773
1172c19:dd:d9:dd:c25:c25:94de:3774/1282c19:dd:d9:dd:c25:c25:94de:3774
1182c19:dd:d9:dd:c25:c25:94de:3775/1282c19:dd:d9:dd:c25:c25:94de:3775
1192c19:dd:d9:dd:c25:c25:94de:3776/1282c19:dd:d9:dd:c25:c25:94de:3776
1202c19:dd:d9:dd:c25:c25:94de:3777/1282c19:dd:d9:dd:c25:c25:94de:3777
1212c19:dd:d9:dd:c25:c25:94de:3778/1282c19:dd:d9:dd:c25:c25:94de:3778
1222c19:dd:d9:dd:c25:c25:94de:3779/1282c19:dd:d9:dd:c25:c25:94de:3779
1232c19:dd:d9:dd:c25:c25:94de:377a/1282c19:dd:d9:dd:c25:c25:94de:377a
1242c19:dd:d9:dd:c25:c25:94de:377b/1282c19:dd:d9:dd:c25:c25:94de:377b
1252c19:dd:d9:dd:c25:c25:94de:377c/1282c19:dd:d9:dd:c25:c25:94de:377c
1262c19:dd:d9:dd:c25:c25:94de:377d/1282c19:dd:d9:dd:c25:c25:94de:377d
1272c19:dd:d9:dd:c25:c25:94de:377e/1282c19:dd:d9:dd:c25:c25:94de:377e
1282c19:dd:d9:dd:c25:c25:94de:377f/1282c19:dd:d9:dd:c25:c25:94de:377f
1292c19:dd:d9:dd:c25:c25:94de:3780/1282c19:dd:d9:dd:c25:c25:94de:3780
1302c19:dd:d9:dd:c25:c25:94de:3781/1282c19:dd:d9:dd:c25:c25:94de:3781
1312c19:dd:d9:dd:c25:c25:94de:3782/1282c19:dd:d9:dd:c25:c25:94de:3782
1322c19:dd:d9:dd:c25:c25:94de:3783/1282c19:dd:d9:dd:c25:c25:94de:3783
1332c19:dd:d9:dd:c25:c25:94de:3784/1282c19:dd:d9:dd:c25:c25:94de:3784
1342c19:dd:d9:dd:c25:c25:94de:3785/1282c19:dd:d9:dd:c25:c25:94de:3785
1352c19:dd:d9:dd:c25:c25:94de:3786/1282c19:dd:d9:dd:c25:c25:94de:3786
1362c19:dd:d9:dd:c25:c25:94de:3787/1282c19:dd:d9:dd:c25:c25:94de:3787
1372c19:dd:d9:dd:c25:c25:94de:3788/1282c19:dd:d9:dd:c25:c25:94de:3788
1382c19:dd:d9:dd:c25:c25:94de:3789/1282c19:dd:d9:dd:c25:c25:94de:3789
1392c19:dd:d9:dd:c25:c25:94de:378a/1282c19:dd:d9:dd:c25:c25:94de:378a
1402c19:dd:d9:dd:c25:c25:94de:378b/1282c19:dd:d9:dd:c25:c25:94de:378b
1412c19:dd:d9:dd:c25:c25:94de:378c/1282c19:dd:d9:dd:c25:c25:94de:378c
1422c19:dd:d9:dd:c25:c25:94de:378d/1282c19:dd:d9:dd:c25:c25:94de:378d
1432c19:dd:d9:dd:c25:c25:94de:378e/1282c19:dd:d9:dd:c25:c25:94de:378e
1442c19:dd:d9:dd:c25:c25:94de:378f/1282c19:dd:d9:dd:c25:c25:94de:378f
1452c19:dd:d9:dd:c25:c25:94de:3790/1282c19:dd:d9:dd:c25:c25:94de:3790
1462c19:dd:d9:dd:c25:c25:94de:3791/1282c19:dd:d9:dd:c25:c25:94de:3791
1472c19:dd:d9:dd:c25:c25:94de:3792/1282c19:dd:d9:dd:c25:c25:94de:3792
1482c19:dd:d9:dd:c25:c25:94de:3793/1282c19:dd:d9:dd:c25:c25:94de:3793
1492c19:dd:d9:dd:c25:c25:94de:3794/1282c19:dd:d9:dd:c25:c25:94de:3794
1502c19:dd:d9:dd:c25:c25:94de:3795/1282c19:dd:d9:dd:c25:c25:94de:3795
1512c19:dd:d9:dd:c25:c25:94de:3796/1282c19:dd:d9:dd:c25:c25:94de:3796
1522c19:dd:d9:dd:c25:c25:94de:3797/1282c19:dd:d9:dd:c25:c25:94de:3797
1532c19:dd:d9:dd:c25:c25:94de:3798/1282c19:dd:d9:dd:c25:c25:94de:3798
1542c19:dd:d9:dd:c25:c25:94de:3799/1282c19:dd:d9:dd:c25:c25:94de:3799
1552c19:dd:d9:dd:c25:c25:94de:379a/1282c19:dd:d9:dd:c25:c25:94de:379a
1562c19:dd:d9:dd:c25:c25:94de:379b/1282c19:dd:d9:dd:c25:c25:94de:379b
1572c19:dd:d9:dd:c25:c25:94de:379c/1282c19:dd:d9:dd:c25:c25:94de:379c
1582c19:dd:d9:dd:c25:c25:94de:379d/1282c19:dd:d9:dd:c25:c25:94de:379d
1592c19:dd:d9:dd:c25:c25:94de:379e/1282c19:dd:d9:dd:c25:c25:94de:379e
1602c19:dd:d9:dd:c25:c25:94de:379f/1282c19:dd:d9:dd:c25:c25:94de:379f
1612c19:dd:d9:dd:c25:c25:94de:37a0/1282c19:dd:d9:dd:c25:c25:94de:37a0
1622c19:dd:d9:dd:c25:c25:94de:37a1/1282c19:dd:d9:dd:c25:c25:94de:37a1
1632c19:dd:d9:dd:c25:c25:94de:37a2/1282c19:dd:d9:dd:c25:c25:94de:37a2
1642c19:dd:d9:dd:c25:c25:94de:37a3/1282c19:dd:d9:dd:c25:c25:94de:37a3
1652c19:dd:d9:dd:c25:c25:94de:37a4/1282c19:dd:d9:dd:c25:c25:94de:37a4
1662c19:dd:d9:dd:c25:c25:94de:37a5/1282c19:dd:d9:dd:c25:c25:94de:37a5
1672c19:dd:d9:dd:c25:c25:94de:37a6/1282c19:dd:d9:dd:c25:c25:94de:37a6
1682c19:dd:d9:dd:c25:c25:94de:37a7/1282c19:dd:d9:dd:c25:c25:94de:37a7
1692c19:dd:d9:dd:c25:c25:94de:37a8/1282c19:dd:d9:dd:c25:c25:94de:37a8
1702c19:dd:d9:dd:c25:c25:94de:37a9/1282c19:dd:d9:dd:c25:c25:94de:37a9
1712c19:dd:d9:dd:c25:c25:94de:37aa/1282c19:dd:d9:dd:c25:c25:94de:37aa
1722c19:dd:d9:dd:c25:c25:94de:37ab/1282c19:dd:d9:dd:c25:c25:94de:37ab
1732c19:dd:d9:dd:c25:c25:94de:37ac/1282c19:dd:d9:dd:c25:c25:94de:37ac
1742c19:dd:d9:dd:c25:c25:94de:37ad/1282c19:dd:d9:dd:c25:c25:94de:37ad
1752c19:dd:d9:dd:c25:c25:94de:37ae/1282c19:dd:d9:dd:c25:c25:94de:37ae
1762c19:dd:d9:dd:c25:c25:94de:37af/1282c19:dd:d9:dd:c25:c25:94de:37af
1772c19:dd:d9:dd:c25:c25:94de:37b0/1282c19:dd:d9:dd:c25:c25:94de:37b0
1782c19:dd:d9:dd:c25:c25:94de:37b1/1282c19:dd:d9:dd:c25:c25:94de:37b1
1792c19:dd:d9:dd:c25:c25:94de:37b2/1282c19:dd:d9:dd:c25:c25:94de:37b2
1802c19:dd:d9:dd:c25:c25:94de:37b3/1282c19:dd:d9:dd:c25:c25:94de:37b3
1812c19:dd:d9:dd:c25:c25:94de:37b4/1282c19:dd:d9:dd:c25:c25:94de:37b4
1822c19:dd:d9:dd:c25:c25:94de:37b5/1282c19:dd:d9:dd:c25:c25:94de:37b5
1832c19:dd:d9:dd:c25:c25:94de:37b6/1282c19:dd:d9:dd:c25:c25:94de:37b6
1842c19:dd:d9:dd:c25:c25:94de:37b7/1282c19:dd:d9:dd:c25:c25:94de:37b7
1852c19:dd:d9:dd:c25:c25:94de:37b8/1282c19:dd:d9:dd:c25:c25:94de:37b8
1862c19:dd:d9:dd:c25:c25:94de:37b9/1282c19:dd:d9:dd:c25:c25:94de:37b9
1872c19:dd:d9:dd:c25:c25:94de:37ba/1282c19:dd:d9:dd:c25:c25:94de:37ba
1882c19:dd:d9:dd:c25:c25:94de:37bb/1282c19:dd:d9:dd:c25:c25:94de:37bb
1892c19:dd:d9:dd:c25:c25:94de:37bc/1282c19:dd:d9:dd:c25:c25:94de:37bc
1902c19:dd:d9:dd:c25:c25:94de:37bd/1282c19:dd:d9:dd:c25:c25:94de:37bd
1912c19:dd:d9:dd:c25:c25:94de:37be/1282c19:dd:d9:dd:c25:c25:94de:37be
1922c19:dd:d9:dd:c25:c25:94de:37bf/1282c19:dd:d9:dd:c25:c25:94de:37bf
1932c19:dd:d9:dd:c25:c25:94de:37c0/1282c19:dd:d9:dd:c25:c25:94de:37c0
1942c19:dd:d9:dd:c25:c25:94de:37c1/1282c19:dd:d9:dd:c25:c25:94de:37c1
1952c19:dd:d9:dd:c25:c25:94de:37c2/1282c19:dd:d9:dd:c25:c25:94de:37c2
1962c19:dd:d9:dd:c25:c25:94de:37c3/1282c19:dd:d9:dd:c25:c25:94de:37c3
1972c19:dd:d9:dd:c25:c25:94de:37c4/1282c19:dd:d9:dd:c25:c25:94de:37c4
1982c19:dd:d9:dd:c25:c25:94de:37c5/1282c19:dd:d9:dd:c25:c25:94de:37c5
1992c19:dd:d9:dd:c25:c25:94de:37c6/1282c19:dd:d9:dd:c25:c25:94de:37c6
2002c19:dd:d9:dd:c25:c25:94de:37c7/1282c19:dd:d9:dd:c25:c25:94de:37c7
2012c19:dd:d9:dd:c25:c25:94de:37c8/1282c19:dd:d9:dd:c25:c25:94de:37c8
2022c19:dd:d9:dd:c25:c25:94de:37c9/1282c19:dd:d9:dd:c25:c25:94de:37c9
2032c19:dd:d9:dd:c25:c25:94de:37ca/1282c19:dd:d9:dd:c25:c25:94de:37ca
2042c19:dd:d9:dd:c25:c25:94de:37cb/1282c19:dd:d9:dd:c25:c25:94de:37cb
2052c19:dd:d9:dd:c25:c25:94de:37cc/1282c19:dd:d9:dd:c25:c25:94de:37cc
2062c19:dd:d9:dd:c25:c25:94de:37cd/1282c19:dd:d9:dd:c25:c25:94de:37cd
2072c19:dd:d9:dd:c25:c25:94de:37ce/1282c19:dd:d9:dd:c25:c25:94de:37ce
2082c19:dd:d9:dd:c25:c25:94de:37cf/1282c19:dd:d9:dd:c25:c25:94de:37cf
2092c19:dd:d9:dd:c25:c25:94de:37d0/1282c19:dd:d9:dd:c25:c25:94de:37d0
2102c19:dd:d9:dd:c25:c25:94de:37d1/1282c19:dd:d9:dd:c25:c25:94de:37d1
2112c19:dd:d9:dd:c25:c25:94de:37d2/1282c19:dd:d9:dd:c25:c25:94de:37d2
2122c19:dd:d9:dd:c25:c25:94de:37d3/1282c19:dd:d9:dd:c25:c25:94de:37d3
2132c19:dd:d9:dd:c25:c25:94de:37d4/1282c19:dd:d9:dd:c25:c25:94de:37d4
2142c19:dd:d9:dd:c25:c25:94de:37d5/1282c19:dd:d9:dd:c25:c25:94de:37d5
2152c19:dd:d9:dd:c25:c25:94de:37d6/1282c19:dd:d9:dd:c25:c25:94de:37d6
2162c19:dd:d9:dd:c25:c25:94de:37d7/1282c19:dd:d9:dd:c25:c25:94de:37d7
2172c19:dd:d9:dd:c25:c25:94de:37d8/1282c19:dd:d9:dd:c25:c25:94de:37d8
2182c19:dd:d9:dd:c25:c25:94de:37d9/1282c19:dd:d9:dd:c25:c25:94de:37d9
2192c19:dd:d9:dd:c25:c25:94de:37da/1282c19:dd:d9:dd:c25:c25:94de:37da
2202c19:dd:d9:dd:c25:c25:94de:37db/1282c19:dd:d9:dd:c25:c25:94de:37db
2212c19:dd:d9:dd:c25:c25:94de:37dc/1282c19:dd:d9:dd:c25:c25:94de:37dc
2222c19:dd:d9:dd:c25:c25:94de:37dd/1282c19:dd:d9:dd:c25:c25:94de:37dd
2232c19:dd:d9:dd:c25:c25:94de:37de/1282c19:dd:d9:dd:c25:c25:94de:37de
2242c19:dd:d9:dd:c25:c25:94de:37df/1282c19:dd:d9:dd:c25:c25:94de:37df
2252c19:dd:d9:dd:c25:c25:94de:37e0/1282c19:dd:d9:dd:c25:c25:94de:37e0
2262c19:dd:d9:dd:c25:c25:94de:37e1/1282c19:dd:d9:dd:c25:c25:94de:37e1
2272c19:dd:d9:dd:c25:c25:94de:37e2/1282c19:dd:d9:dd:c25:c25:94de:37e2
2282c19:dd:d9:dd:c25:c25:94de:37e3/1282c19:dd:d9:dd:c25:c25:94de:37e3
2292c19:dd:d9:dd:c25:c25:94de:37e4/1282c19:dd:d9:dd:c25:c25:94de:37e4
2302c19:dd:d9:dd:c25:c25:94de:37e5/1282c19:dd:d9:dd:c25:c25:94de:37e5
2312c19:dd:d9:dd:c25:c25:94de:37e6/1282c19:dd:d9:dd:c25:c25:94de:37e6
2322c19:dd:d9:dd:c25:c25:94de:37e7/1282c19:dd:d9:dd:c25:c25:94de:37e7
2332c19:dd:d9:dd:c25:c25:94de:37e8/1282c19:dd:d9:dd:c25:c25:94de:37e8
2342c19:dd:d9:dd:c25:c25:94de:37e9/1282c19:dd:d9:dd:c25:c25:94de:37e9
2352c19:dd:d9:dd:c25:c25:94de:37ea/1282c19:dd:d9:dd:c25:c25:94de:37ea
2362c19:dd:d9:dd:c25:c25:94de:37eb/1282c19:dd:d9:dd:c25:c25:94de:37eb
2372c19:dd:d9:dd:c25:c25:94de:37ec/1282c19:dd:d9:dd:c25:c25:94de:37ec
2382c19:dd:d9:dd:c25:c25:94de:37ed/1282c19:dd:d9:dd:c25:c25:94de:37ed
2392c19:dd:d9:dd:c25:c25:94de:37ee/1282c19:dd:d9:dd:c25:c25:94de:37ee
2402c19:dd:d9:dd:c25:c25:94de:37ef/1282c19:dd:d9:dd:c25:c25:94de:37ef
2412c19:dd:d9:dd:c25:c25:94de:37f0/1282c19:dd:d9:dd:c25:c25:94de:37f0
2422c19:dd:d9:dd:c25:c25:94de:37f1/1282c19:dd:d9:dd:c25:c25:94de:37f1
2432c19:dd:d9:dd:c25:c25:94de:37f2/1282c19:dd:d9:dd:c25:c25:94de:37f2
2442c19:dd:d9:dd:c25:c25:94de:37f3/1282c19:dd:d9:dd:c25:c25:94de:37f3
2452c19:dd:d9:dd:c25:c25:94de:37f4/1282c19:dd:d9:dd:c25:c25:94de:37f4
2462c19:dd:d9:dd:c25:c25:94de:37f5/1282c19:dd:d9:dd:c25:c25:94de:37f5
2472c19:dd:d9:dd:c25:c25:94de:37f6/1282c19:dd:d9:dd:c25:c25:94de:37f6
2482c19:dd:d9:dd:c25:c25:94de:37f7/1282c19:dd:d9:dd:c25:c25:94de:37f7
2492c19:dd:d9:dd:c25:c25:94de:37f8/1282c19:dd:d9:dd:c25:c25:94de:37f8
2502c19:dd:d9:dd:c25:c25:94de:37f9/1282c19:dd:d9:dd:c25:c25:94de:37f9
2512c19:dd:d9:dd:c25:c25:94de:37fa/1282c19:dd:d9:dd:c25:c25:94de:37fa
2522c19:dd:d9:dd:c25:c25:94de:37fb/1282c19:dd:d9:dd:c25:c25:94de:37fb
2532c19:dd:d9:dd:c25:c25:94de:37fc/1282c19:dd:d9:dd:c25:c25:94de:37fc
2542c19:dd:d9:dd:c25:c25:94de:37fd/1282c19:dd:d9:dd:c25:c25:94de:37fd
2552c19:dd:d9:dd:c25:c25:94de:37fe/1282c19:dd:d9:dd:c25:c25:94de:37fe
2562c19:dd:d9:dd:c25:c25:94de:37ff/1282c19:dd:d9:dd:c25:c25:94de:37ff

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.