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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:9600/120
First address
2c19:dd:d9:dd:c25:c25:94de:9600
Last address
2c19:dd:d9:dd:c25:c25:94de:96ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:00d9:00dd:0c25:0c25:94de:9600
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
6.9.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:9600/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:d9:dd:c25:c25:94de:9600/1282c19:dd:d9:dd:c25:c25:94de:9600
22c19:dd:d9:dd:c25:c25:94de:9601/1282c19:dd:d9:dd:c25:c25:94de:9601
32c19:dd:d9:dd:c25:c25:94de:9602/1282c19:dd:d9:dd:c25:c25:94de:9602
42c19:dd:d9:dd:c25:c25:94de:9603/1282c19:dd:d9:dd:c25:c25:94de:9603
52c19:dd:d9:dd:c25:c25:94de:9604/1282c19:dd:d9:dd:c25:c25:94de:9604
62c19:dd:d9:dd:c25:c25:94de:9605/1282c19:dd:d9:dd:c25:c25:94de:9605
72c19:dd:d9:dd:c25:c25:94de:9606/1282c19:dd:d9:dd:c25:c25:94de:9606
82c19:dd:d9:dd:c25:c25:94de:9607/1282c19:dd:d9:dd:c25:c25:94de:9607
92c19:dd:d9:dd:c25:c25:94de:9608/1282c19:dd:d9:dd:c25:c25:94de:9608
102c19:dd:d9:dd:c25:c25:94de:9609/1282c19:dd:d9:dd:c25:c25:94de:9609
112c19:dd:d9:dd:c25:c25:94de:960a/1282c19:dd:d9:dd:c25:c25:94de:960a
122c19:dd:d9:dd:c25:c25:94de:960b/1282c19:dd:d9:dd:c25:c25:94de:960b
132c19:dd:d9:dd:c25:c25:94de:960c/1282c19:dd:d9:dd:c25:c25:94de:960c
142c19:dd:d9:dd:c25:c25:94de:960d/1282c19:dd:d9:dd:c25:c25:94de:960d
152c19:dd:d9:dd:c25:c25:94de:960e/1282c19:dd:d9:dd:c25:c25:94de:960e
162c19:dd:d9:dd:c25:c25:94de:960f/1282c19:dd:d9:dd:c25:c25:94de:960f
172c19:dd:d9:dd:c25:c25:94de:9610/1282c19:dd:d9:dd:c25:c25:94de:9610
182c19:dd:d9:dd:c25:c25:94de:9611/1282c19:dd:d9:dd:c25:c25:94de:9611
192c19:dd:d9:dd:c25:c25:94de:9612/1282c19:dd:d9:dd:c25:c25:94de:9612
202c19:dd:d9:dd:c25:c25:94de:9613/1282c19:dd:d9:dd:c25:c25:94de:9613
212c19:dd:d9:dd:c25:c25:94de:9614/1282c19:dd:d9:dd:c25:c25:94de:9614
222c19:dd:d9:dd:c25:c25:94de:9615/1282c19:dd:d9:dd:c25:c25:94de:9615
232c19:dd:d9:dd:c25:c25:94de:9616/1282c19:dd:d9:dd:c25:c25:94de:9616
242c19:dd:d9:dd:c25:c25:94de:9617/1282c19:dd:d9:dd:c25:c25:94de:9617
252c19:dd:d9:dd:c25:c25:94de:9618/1282c19:dd:d9:dd:c25:c25:94de:9618
262c19:dd:d9:dd:c25:c25:94de:9619/1282c19:dd:d9:dd:c25:c25:94de:9619
272c19:dd:d9:dd:c25:c25:94de:961a/1282c19:dd:d9:dd:c25:c25:94de:961a
282c19:dd:d9:dd:c25:c25:94de:961b/1282c19:dd:d9:dd:c25:c25:94de:961b
292c19:dd:d9:dd:c25:c25:94de:961c/1282c19:dd:d9:dd:c25:c25:94de:961c
302c19:dd:d9:dd:c25:c25:94de:961d/1282c19:dd:d9:dd:c25:c25:94de:961d
312c19:dd:d9:dd:c25:c25:94de:961e/1282c19:dd:d9:dd:c25:c25:94de:961e
322c19:dd:d9:dd:c25:c25:94de:961f/1282c19:dd:d9:dd:c25:c25:94de:961f
332c19:dd:d9:dd:c25:c25:94de:9620/1282c19:dd:d9:dd:c25:c25:94de:9620
342c19:dd:d9:dd:c25:c25:94de:9621/1282c19:dd:d9:dd:c25:c25:94de:9621
352c19:dd:d9:dd:c25:c25:94de:9622/1282c19:dd:d9:dd:c25:c25:94de:9622
362c19:dd:d9:dd:c25:c25:94de:9623/1282c19:dd:d9:dd:c25:c25:94de:9623
372c19:dd:d9:dd:c25:c25:94de:9624/1282c19:dd:d9:dd:c25:c25:94de:9624
382c19:dd:d9:dd:c25:c25:94de:9625/1282c19:dd:d9:dd:c25:c25:94de:9625
392c19:dd:d9:dd:c25:c25:94de:9626/1282c19:dd:d9:dd:c25:c25:94de:9626
402c19:dd:d9:dd:c25:c25:94de:9627/1282c19:dd:d9:dd:c25:c25:94de:9627
412c19:dd:d9:dd:c25:c25:94de:9628/1282c19:dd:d9:dd:c25:c25:94de:9628
422c19:dd:d9:dd:c25:c25:94de:9629/1282c19:dd:d9:dd:c25:c25:94de:9629
432c19:dd:d9:dd:c25:c25:94de:962a/1282c19:dd:d9:dd:c25:c25:94de:962a
442c19:dd:d9:dd:c25:c25:94de:962b/1282c19:dd:d9:dd:c25:c25:94de:962b
452c19:dd:d9:dd:c25:c25:94de:962c/1282c19:dd:d9:dd:c25:c25:94de:962c
462c19:dd:d9:dd:c25:c25:94de:962d/1282c19:dd:d9:dd:c25:c25:94de:962d
472c19:dd:d9:dd:c25:c25:94de:962e/1282c19:dd:d9:dd:c25:c25:94de:962e
482c19:dd:d9:dd:c25:c25:94de:962f/1282c19:dd:d9:dd:c25:c25:94de:962f
492c19:dd:d9:dd:c25:c25:94de:9630/1282c19:dd:d9:dd:c25:c25:94de:9630
502c19:dd:d9:dd:c25:c25:94de:9631/1282c19:dd:d9:dd:c25:c25:94de:9631
512c19:dd:d9:dd:c25:c25:94de:9632/1282c19:dd:d9:dd:c25:c25:94de:9632
522c19:dd:d9:dd:c25:c25:94de:9633/1282c19:dd:d9:dd:c25:c25:94de:9633
532c19:dd:d9:dd:c25:c25:94de:9634/1282c19:dd:d9:dd:c25:c25:94de:9634
542c19:dd:d9:dd:c25:c25:94de:9635/1282c19:dd:d9:dd:c25:c25:94de:9635
552c19:dd:d9:dd:c25:c25:94de:9636/1282c19:dd:d9:dd:c25:c25:94de:9636
562c19:dd:d9:dd:c25:c25:94de:9637/1282c19:dd:d9:dd:c25:c25:94de:9637
572c19:dd:d9:dd:c25:c25:94de:9638/1282c19:dd:d9:dd:c25:c25:94de:9638
582c19:dd:d9:dd:c25:c25:94de:9639/1282c19:dd:d9:dd:c25:c25:94de:9639
592c19:dd:d9:dd:c25:c25:94de:963a/1282c19:dd:d9:dd:c25:c25:94de:963a
602c19:dd:d9:dd:c25:c25:94de:963b/1282c19:dd:d9:dd:c25:c25:94de:963b
612c19:dd:d9:dd:c25:c25:94de:963c/1282c19:dd:d9:dd:c25:c25:94de:963c
622c19:dd:d9:dd:c25:c25:94de:963d/1282c19:dd:d9:dd:c25:c25:94de:963d
632c19:dd:d9:dd:c25:c25:94de:963e/1282c19:dd:d9:dd:c25:c25:94de:963e
642c19:dd:d9:dd:c25:c25:94de:963f/1282c19:dd:d9:dd:c25:c25:94de:963f
652c19:dd:d9:dd:c25:c25:94de:9640/1282c19:dd:d9:dd:c25:c25:94de:9640
662c19:dd:d9:dd:c25:c25:94de:9641/1282c19:dd:d9:dd:c25:c25:94de:9641
672c19:dd:d9:dd:c25:c25:94de:9642/1282c19:dd:d9:dd:c25:c25:94de:9642
682c19:dd:d9:dd:c25:c25:94de:9643/1282c19:dd:d9:dd:c25:c25:94de:9643
692c19:dd:d9:dd:c25:c25:94de:9644/1282c19:dd:d9:dd:c25:c25:94de:9644
702c19:dd:d9:dd:c25:c25:94de:9645/1282c19:dd:d9:dd:c25:c25:94de:9645
712c19:dd:d9:dd:c25:c25:94de:9646/1282c19:dd:d9:dd:c25:c25:94de:9646
722c19:dd:d9:dd:c25:c25:94de:9647/1282c19:dd:d9:dd:c25:c25:94de:9647
732c19:dd:d9:dd:c25:c25:94de:9648/1282c19:dd:d9:dd:c25:c25:94de:9648
742c19:dd:d9:dd:c25:c25:94de:9649/1282c19:dd:d9:dd:c25:c25:94de:9649
752c19:dd:d9:dd:c25:c25:94de:964a/1282c19:dd:d9:dd:c25:c25:94de:964a
762c19:dd:d9:dd:c25:c25:94de:964b/1282c19:dd:d9:dd:c25:c25:94de:964b
772c19:dd:d9:dd:c25:c25:94de:964c/1282c19:dd:d9:dd:c25:c25:94de:964c
782c19:dd:d9:dd:c25:c25:94de:964d/1282c19:dd:d9:dd:c25:c25:94de:964d
792c19:dd:d9:dd:c25:c25:94de:964e/1282c19:dd:d9:dd:c25:c25:94de:964e
802c19:dd:d9:dd:c25:c25:94de:964f/1282c19:dd:d9:dd:c25:c25:94de:964f
812c19:dd:d9:dd:c25:c25:94de:9650/1282c19:dd:d9:dd:c25:c25:94de:9650
822c19:dd:d9:dd:c25:c25:94de:9651/1282c19:dd:d9:dd:c25:c25:94de:9651
832c19:dd:d9:dd:c25:c25:94de:9652/1282c19:dd:d9:dd:c25:c25:94de:9652
842c19:dd:d9:dd:c25:c25:94de:9653/1282c19:dd:d9:dd:c25:c25:94de:9653
852c19:dd:d9:dd:c25:c25:94de:9654/1282c19:dd:d9:dd:c25:c25:94de:9654
862c19:dd:d9:dd:c25:c25:94de:9655/1282c19:dd:d9:dd:c25:c25:94de:9655
872c19:dd:d9:dd:c25:c25:94de:9656/1282c19:dd:d9:dd:c25:c25:94de:9656
882c19:dd:d9:dd:c25:c25:94de:9657/1282c19:dd:d9:dd:c25:c25:94de:9657
892c19:dd:d9:dd:c25:c25:94de:9658/1282c19:dd:d9:dd:c25:c25:94de:9658
902c19:dd:d9:dd:c25:c25:94de:9659/1282c19:dd:d9:dd:c25:c25:94de:9659
912c19:dd:d9:dd:c25:c25:94de:965a/1282c19:dd:d9:dd:c25:c25:94de:965a
922c19:dd:d9:dd:c25:c25:94de:965b/1282c19:dd:d9:dd:c25:c25:94de:965b
932c19:dd:d9:dd:c25:c25:94de:965c/1282c19:dd:d9:dd:c25:c25:94de:965c
942c19:dd:d9:dd:c25:c25:94de:965d/1282c19:dd:d9:dd:c25:c25:94de:965d
952c19:dd:d9:dd:c25:c25:94de:965e/1282c19:dd:d9:dd:c25:c25:94de:965e
962c19:dd:d9:dd:c25:c25:94de:965f/1282c19:dd:d9:dd:c25:c25:94de:965f
972c19:dd:d9:dd:c25:c25:94de:9660/1282c19:dd:d9:dd:c25:c25:94de:9660
982c19:dd:d9:dd:c25:c25:94de:9661/1282c19:dd:d9:dd:c25:c25:94de:9661
992c19:dd:d9:dd:c25:c25:94de:9662/1282c19:dd:d9:dd:c25:c25:94de:9662
1002c19:dd:d9:dd:c25:c25:94de:9663/1282c19:dd:d9:dd:c25:c25:94de:9663
1012c19:dd:d9:dd:c25:c25:94de:9664/1282c19:dd:d9:dd:c25:c25:94de:9664
1022c19:dd:d9:dd:c25:c25:94de:9665/1282c19:dd:d9:dd:c25:c25:94de:9665
1032c19:dd:d9:dd:c25:c25:94de:9666/1282c19:dd:d9:dd:c25:c25:94de:9666
1042c19:dd:d9:dd:c25:c25:94de:9667/1282c19:dd:d9:dd:c25:c25:94de:9667
1052c19:dd:d9:dd:c25:c25:94de:9668/1282c19:dd:d9:dd:c25:c25:94de:9668
1062c19:dd:d9:dd:c25:c25:94de:9669/1282c19:dd:d9:dd:c25:c25:94de:9669
1072c19:dd:d9:dd:c25:c25:94de:966a/1282c19:dd:d9:dd:c25:c25:94de:966a
1082c19:dd:d9:dd:c25:c25:94de:966b/1282c19:dd:d9:dd:c25:c25:94de:966b
1092c19:dd:d9:dd:c25:c25:94de:966c/1282c19:dd:d9:dd:c25:c25:94de:966c
1102c19:dd:d9:dd:c25:c25:94de:966d/1282c19:dd:d9:dd:c25:c25:94de:966d
1112c19:dd:d9:dd:c25:c25:94de:966e/1282c19:dd:d9:dd:c25:c25:94de:966e
1122c19:dd:d9:dd:c25:c25:94de:966f/1282c19:dd:d9:dd:c25:c25:94de:966f
1132c19:dd:d9:dd:c25:c25:94de:9670/1282c19:dd:d9:dd:c25:c25:94de:9670
1142c19:dd:d9:dd:c25:c25:94de:9671/1282c19:dd:d9:dd:c25:c25:94de:9671
1152c19:dd:d9:dd:c25:c25:94de:9672/1282c19:dd:d9:dd:c25:c25:94de:9672
1162c19:dd:d9:dd:c25:c25:94de:9673/1282c19:dd:d9:dd:c25:c25:94de:9673
1172c19:dd:d9:dd:c25:c25:94de:9674/1282c19:dd:d9:dd:c25:c25:94de:9674
1182c19:dd:d9:dd:c25:c25:94de:9675/1282c19:dd:d9:dd:c25:c25:94de:9675
1192c19:dd:d9:dd:c25:c25:94de:9676/1282c19:dd:d9:dd:c25:c25:94de:9676
1202c19:dd:d9:dd:c25:c25:94de:9677/1282c19:dd:d9:dd:c25:c25:94de:9677
1212c19:dd:d9:dd:c25:c25:94de:9678/1282c19:dd:d9:dd:c25:c25:94de:9678
1222c19:dd:d9:dd:c25:c25:94de:9679/1282c19:dd:d9:dd:c25:c25:94de:9679
1232c19:dd:d9:dd:c25:c25:94de:967a/1282c19:dd:d9:dd:c25:c25:94de:967a
1242c19:dd:d9:dd:c25:c25:94de:967b/1282c19:dd:d9:dd:c25:c25:94de:967b
1252c19:dd:d9:dd:c25:c25:94de:967c/1282c19:dd:d9:dd:c25:c25:94de:967c
1262c19:dd:d9:dd:c25:c25:94de:967d/1282c19:dd:d9:dd:c25:c25:94de:967d
1272c19:dd:d9:dd:c25:c25:94de:967e/1282c19:dd:d9:dd:c25:c25:94de:967e
1282c19:dd:d9:dd:c25:c25:94de:967f/1282c19:dd:d9:dd:c25:c25:94de:967f
1292c19:dd:d9:dd:c25:c25:94de:9680/1282c19:dd:d9:dd:c25:c25:94de:9680
1302c19:dd:d9:dd:c25:c25:94de:9681/1282c19:dd:d9:dd:c25:c25:94de:9681
1312c19:dd:d9:dd:c25:c25:94de:9682/1282c19:dd:d9:dd:c25:c25:94de:9682
1322c19:dd:d9:dd:c25:c25:94de:9683/1282c19:dd:d9:dd:c25:c25:94de:9683
1332c19:dd:d9:dd:c25:c25:94de:9684/1282c19:dd:d9:dd:c25:c25:94de:9684
1342c19:dd:d9:dd:c25:c25:94de:9685/1282c19:dd:d9:dd:c25:c25:94de:9685
1352c19:dd:d9:dd:c25:c25:94de:9686/1282c19:dd:d9:dd:c25:c25:94de:9686
1362c19:dd:d9:dd:c25:c25:94de:9687/1282c19:dd:d9:dd:c25:c25:94de:9687
1372c19:dd:d9:dd:c25:c25:94de:9688/1282c19:dd:d9:dd:c25:c25:94de:9688
1382c19:dd:d9:dd:c25:c25:94de:9689/1282c19:dd:d9:dd:c25:c25:94de:9689
1392c19:dd:d9:dd:c25:c25:94de:968a/1282c19:dd:d9:dd:c25:c25:94de:968a
1402c19:dd:d9:dd:c25:c25:94de:968b/1282c19:dd:d9:dd:c25:c25:94de:968b
1412c19:dd:d9:dd:c25:c25:94de:968c/1282c19:dd:d9:dd:c25:c25:94de:968c
1422c19:dd:d9:dd:c25:c25:94de:968d/1282c19:dd:d9:dd:c25:c25:94de:968d
1432c19:dd:d9:dd:c25:c25:94de:968e/1282c19:dd:d9:dd:c25:c25:94de:968e
1442c19:dd:d9:dd:c25:c25:94de:968f/1282c19:dd:d9:dd:c25:c25:94de:968f
1452c19:dd:d9:dd:c25:c25:94de:9690/1282c19:dd:d9:dd:c25:c25:94de:9690
1462c19:dd:d9:dd:c25:c25:94de:9691/1282c19:dd:d9:dd:c25:c25:94de:9691
1472c19:dd:d9:dd:c25:c25:94de:9692/1282c19:dd:d9:dd:c25:c25:94de:9692
1482c19:dd:d9:dd:c25:c25:94de:9693/1282c19:dd:d9:dd:c25:c25:94de:9693
1492c19:dd:d9:dd:c25:c25:94de:9694/1282c19:dd:d9:dd:c25:c25:94de:9694
1502c19:dd:d9:dd:c25:c25:94de:9695/1282c19:dd:d9:dd:c25:c25:94de:9695
1512c19:dd:d9:dd:c25:c25:94de:9696/1282c19:dd:d9:dd:c25:c25:94de:9696
1522c19:dd:d9:dd:c25:c25:94de:9697/1282c19:dd:d9:dd:c25:c25:94de:9697
1532c19:dd:d9:dd:c25:c25:94de:9698/1282c19:dd:d9:dd:c25:c25:94de:9698
1542c19:dd:d9:dd:c25:c25:94de:9699/1282c19:dd:d9:dd:c25:c25:94de:9699
1552c19:dd:d9:dd:c25:c25:94de:969a/1282c19:dd:d9:dd:c25:c25:94de:969a
1562c19:dd:d9:dd:c25:c25:94de:969b/1282c19:dd:d9:dd:c25:c25:94de:969b
1572c19:dd:d9:dd:c25:c25:94de:969c/1282c19:dd:d9:dd:c25:c25:94de:969c
1582c19:dd:d9:dd:c25:c25:94de:969d/1282c19:dd:d9:dd:c25:c25:94de:969d
1592c19:dd:d9:dd:c25:c25:94de:969e/1282c19:dd:d9:dd:c25:c25:94de:969e
1602c19:dd:d9:dd:c25:c25:94de:969f/1282c19:dd:d9:dd:c25:c25:94de:969f
1612c19:dd:d9:dd:c25:c25:94de:96a0/1282c19:dd:d9:dd:c25:c25:94de:96a0
1622c19:dd:d9:dd:c25:c25:94de:96a1/1282c19:dd:d9:dd:c25:c25:94de:96a1
1632c19:dd:d9:dd:c25:c25:94de:96a2/1282c19:dd:d9:dd:c25:c25:94de:96a2
1642c19:dd:d9:dd:c25:c25:94de:96a3/1282c19:dd:d9:dd:c25:c25:94de:96a3
1652c19:dd:d9:dd:c25:c25:94de:96a4/1282c19:dd:d9:dd:c25:c25:94de:96a4
1662c19:dd:d9:dd:c25:c25:94de:96a5/1282c19:dd:d9:dd:c25:c25:94de:96a5
1672c19:dd:d9:dd:c25:c25:94de:96a6/1282c19:dd:d9:dd:c25:c25:94de:96a6
1682c19:dd:d9:dd:c25:c25:94de:96a7/1282c19:dd:d9:dd:c25:c25:94de:96a7
1692c19:dd:d9:dd:c25:c25:94de:96a8/1282c19:dd:d9:dd:c25:c25:94de:96a8
1702c19:dd:d9:dd:c25:c25:94de:96a9/1282c19:dd:d9:dd:c25:c25:94de:96a9
1712c19:dd:d9:dd:c25:c25:94de:96aa/1282c19:dd:d9:dd:c25:c25:94de:96aa
1722c19:dd:d9:dd:c25:c25:94de:96ab/1282c19:dd:d9:dd:c25:c25:94de:96ab
1732c19:dd:d9:dd:c25:c25:94de:96ac/1282c19:dd:d9:dd:c25:c25:94de:96ac
1742c19:dd:d9:dd:c25:c25:94de:96ad/1282c19:dd:d9:dd:c25:c25:94de:96ad
1752c19:dd:d9:dd:c25:c25:94de:96ae/1282c19:dd:d9:dd:c25:c25:94de:96ae
1762c19:dd:d9:dd:c25:c25:94de:96af/1282c19:dd:d9:dd:c25:c25:94de:96af
1772c19:dd:d9:dd:c25:c25:94de:96b0/1282c19:dd:d9:dd:c25:c25:94de:96b0
1782c19:dd:d9:dd:c25:c25:94de:96b1/1282c19:dd:d9:dd:c25:c25:94de:96b1
1792c19:dd:d9:dd:c25:c25:94de:96b2/1282c19:dd:d9:dd:c25:c25:94de:96b2
1802c19:dd:d9:dd:c25:c25:94de:96b3/1282c19:dd:d9:dd:c25:c25:94de:96b3
1812c19:dd:d9:dd:c25:c25:94de:96b4/1282c19:dd:d9:dd:c25:c25:94de:96b4
1822c19:dd:d9:dd:c25:c25:94de:96b5/1282c19:dd:d9:dd:c25:c25:94de:96b5
1832c19:dd:d9:dd:c25:c25:94de:96b6/1282c19:dd:d9:dd:c25:c25:94de:96b6
1842c19:dd:d9:dd:c25:c25:94de:96b7/1282c19:dd:d9:dd:c25:c25:94de:96b7
1852c19:dd:d9:dd:c25:c25:94de:96b8/1282c19:dd:d9:dd:c25:c25:94de:96b8
1862c19:dd:d9:dd:c25:c25:94de:96b9/1282c19:dd:d9:dd:c25:c25:94de:96b9
1872c19:dd:d9:dd:c25:c25:94de:96ba/1282c19:dd:d9:dd:c25:c25:94de:96ba
1882c19:dd:d9:dd:c25:c25:94de:96bb/1282c19:dd:d9:dd:c25:c25:94de:96bb
1892c19:dd:d9:dd:c25:c25:94de:96bc/1282c19:dd:d9:dd:c25:c25:94de:96bc
1902c19:dd:d9:dd:c25:c25:94de:96bd/1282c19:dd:d9:dd:c25:c25:94de:96bd
1912c19:dd:d9:dd:c25:c25:94de:96be/1282c19:dd:d9:dd:c25:c25:94de:96be
1922c19:dd:d9:dd:c25:c25:94de:96bf/1282c19:dd:d9:dd:c25:c25:94de:96bf
1932c19:dd:d9:dd:c25:c25:94de:96c0/1282c19:dd:d9:dd:c25:c25:94de:96c0
1942c19:dd:d9:dd:c25:c25:94de:96c1/1282c19:dd:d9:dd:c25:c25:94de:96c1
1952c19:dd:d9:dd:c25:c25:94de:96c2/1282c19:dd:d9:dd:c25:c25:94de:96c2
1962c19:dd:d9:dd:c25:c25:94de:96c3/1282c19:dd:d9:dd:c25:c25:94de:96c3
1972c19:dd:d9:dd:c25:c25:94de:96c4/1282c19:dd:d9:dd:c25:c25:94de:96c4
1982c19:dd:d9:dd:c25:c25:94de:96c5/1282c19:dd:d9:dd:c25:c25:94de:96c5
1992c19:dd:d9:dd:c25:c25:94de:96c6/1282c19:dd:d9:dd:c25:c25:94de:96c6
2002c19:dd:d9:dd:c25:c25:94de:96c7/1282c19:dd:d9:dd:c25:c25:94de:96c7
2012c19:dd:d9:dd:c25:c25:94de:96c8/1282c19:dd:d9:dd:c25:c25:94de:96c8
2022c19:dd:d9:dd:c25:c25:94de:96c9/1282c19:dd:d9:dd:c25:c25:94de:96c9
2032c19:dd:d9:dd:c25:c25:94de:96ca/1282c19:dd:d9:dd:c25:c25:94de:96ca
2042c19:dd:d9:dd:c25:c25:94de:96cb/1282c19:dd:d9:dd:c25:c25:94de:96cb
2052c19:dd:d9:dd:c25:c25:94de:96cc/1282c19:dd:d9:dd:c25:c25:94de:96cc
2062c19:dd:d9:dd:c25:c25:94de:96cd/1282c19:dd:d9:dd:c25:c25:94de:96cd
2072c19:dd:d9:dd:c25:c25:94de:96ce/1282c19:dd:d9:dd:c25:c25:94de:96ce
2082c19:dd:d9:dd:c25:c25:94de:96cf/1282c19:dd:d9:dd:c25:c25:94de:96cf
2092c19:dd:d9:dd:c25:c25:94de:96d0/1282c19:dd:d9:dd:c25:c25:94de:96d0
2102c19:dd:d9:dd:c25:c25:94de:96d1/1282c19:dd:d9:dd:c25:c25:94de:96d1
2112c19:dd:d9:dd:c25:c25:94de:96d2/1282c19:dd:d9:dd:c25:c25:94de:96d2
2122c19:dd:d9:dd:c25:c25:94de:96d3/1282c19:dd:d9:dd:c25:c25:94de:96d3
2132c19:dd:d9:dd:c25:c25:94de:96d4/1282c19:dd:d9:dd:c25:c25:94de:96d4
2142c19:dd:d9:dd:c25:c25:94de:96d5/1282c19:dd:d9:dd:c25:c25:94de:96d5
2152c19:dd:d9:dd:c25:c25:94de:96d6/1282c19:dd:d9:dd:c25:c25:94de:96d6
2162c19:dd:d9:dd:c25:c25:94de:96d7/1282c19:dd:d9:dd:c25:c25:94de:96d7
2172c19:dd:d9:dd:c25:c25:94de:96d8/1282c19:dd:d9:dd:c25:c25:94de:96d8
2182c19:dd:d9:dd:c25:c25:94de:96d9/1282c19:dd:d9:dd:c25:c25:94de:96d9
2192c19:dd:d9:dd:c25:c25:94de:96da/1282c19:dd:d9:dd:c25:c25:94de:96da
2202c19:dd:d9:dd:c25:c25:94de:96db/1282c19:dd:d9:dd:c25:c25:94de:96db
2212c19:dd:d9:dd:c25:c25:94de:96dc/1282c19:dd:d9:dd:c25:c25:94de:96dc
2222c19:dd:d9:dd:c25:c25:94de:96dd/1282c19:dd:d9:dd:c25:c25:94de:96dd
2232c19:dd:d9:dd:c25:c25:94de:96de/1282c19:dd:d9:dd:c25:c25:94de:96de
2242c19:dd:d9:dd:c25:c25:94de:96df/1282c19:dd:d9:dd:c25:c25:94de:96df
2252c19:dd:d9:dd:c25:c25:94de:96e0/1282c19:dd:d9:dd:c25:c25:94de:96e0
2262c19:dd:d9:dd:c25:c25:94de:96e1/1282c19:dd:d9:dd:c25:c25:94de:96e1
2272c19:dd:d9:dd:c25:c25:94de:96e2/1282c19:dd:d9:dd:c25:c25:94de:96e2
2282c19:dd:d9:dd:c25:c25:94de:96e3/1282c19:dd:d9:dd:c25:c25:94de:96e3
2292c19:dd:d9:dd:c25:c25:94de:96e4/1282c19:dd:d9:dd:c25:c25:94de:96e4
2302c19:dd:d9:dd:c25:c25:94de:96e5/1282c19:dd:d9:dd:c25:c25:94de:96e5
2312c19:dd:d9:dd:c25:c25:94de:96e6/1282c19:dd:d9:dd:c25:c25:94de:96e6
2322c19:dd:d9:dd:c25:c25:94de:96e7/1282c19:dd:d9:dd:c25:c25:94de:96e7
2332c19:dd:d9:dd:c25:c25:94de:96e8/1282c19:dd:d9:dd:c25:c25:94de:96e8
2342c19:dd:d9:dd:c25:c25:94de:96e9/1282c19:dd:d9:dd:c25:c25:94de:96e9
2352c19:dd:d9:dd:c25:c25:94de:96ea/1282c19:dd:d9:dd:c25:c25:94de:96ea
2362c19:dd:d9:dd:c25:c25:94de:96eb/1282c19:dd:d9:dd:c25:c25:94de:96eb
2372c19:dd:d9:dd:c25:c25:94de:96ec/1282c19:dd:d9:dd:c25:c25:94de:96ec
2382c19:dd:d9:dd:c25:c25:94de:96ed/1282c19:dd:d9:dd:c25:c25:94de:96ed
2392c19:dd:d9:dd:c25:c25:94de:96ee/1282c19:dd:d9:dd:c25:c25:94de:96ee
2402c19:dd:d9:dd:c25:c25:94de:96ef/1282c19:dd:d9:dd:c25:c25:94de:96ef
2412c19:dd:d9:dd:c25:c25:94de:96f0/1282c19:dd:d9:dd:c25:c25:94de:96f0
2422c19:dd:d9:dd:c25:c25:94de:96f1/1282c19:dd:d9:dd:c25:c25:94de:96f1
2432c19:dd:d9:dd:c25:c25:94de:96f2/1282c19:dd:d9:dd:c25:c25:94de:96f2
2442c19:dd:d9:dd:c25:c25:94de:96f3/1282c19:dd:d9:dd:c25:c25:94de:96f3
2452c19:dd:d9:dd:c25:c25:94de:96f4/1282c19:dd:d9:dd:c25:c25:94de:96f4
2462c19:dd:d9:dd:c25:c25:94de:96f5/1282c19:dd:d9:dd:c25:c25:94de:96f5
2472c19:dd:d9:dd:c25:c25:94de:96f6/1282c19:dd:d9:dd:c25:c25:94de:96f6
2482c19:dd:d9:dd:c25:c25:94de:96f7/1282c19:dd:d9:dd:c25:c25:94de:96f7
2492c19:dd:d9:dd:c25:c25:94de:96f8/1282c19:dd:d9:dd:c25:c25:94de:96f8
2502c19:dd:d9:dd:c25:c25:94de:96f9/1282c19:dd:d9:dd:c25:c25:94de:96f9
2512c19:dd:d9:dd:c25:c25:94de:96fa/1282c19:dd:d9:dd:c25:c25:94de:96fa
2522c19:dd:d9:dd:c25:c25:94de:96fb/1282c19:dd:d9:dd:c25:c25:94de:96fb
2532c19:dd:d9:dd:c25:c25:94de:96fc/1282c19:dd:d9:dd:c25:c25:94de:96fc
2542c19:dd:d9:dd:c25:c25:94de:96fd/1282c19:dd:d9:dd:c25:c25:94de:96fd
2552c19:dd:d9:dd:c25:c25:94de:96fe/1282c19:dd:d9:dd:c25:c25:94de:96fe
2562c19:dd:d9:dd:c25:c25:94de:96ff/1282c19:dd:d9:dd:c25:c25:94de:96ff

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.