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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:c25:c25:dd:dd:dd:7700/120
First address
2c19:dd:c25:c25:dd:dd:dd:7700
Last address
2c19:dd:c25:c25:dd:dd:dd:77ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:0c25:0c25:00dd:00dd:00dd:7700
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
7.7.d.d.0.0.d.d.0.0.d.d.0.0.5.2.c.0.5.2.c.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:c25:c25:dd:dd:dd:7700/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:c25:c25:dd:dd:dd:7700/1282c19:dd:c25:c25:dd:dd:dd:7700
22c19:dd:c25:c25:dd:dd:dd:7701/1282c19:dd:c25:c25:dd:dd:dd:7701
32c19:dd:c25:c25:dd:dd:dd:7702/1282c19:dd:c25:c25:dd:dd:dd:7702
42c19:dd:c25:c25:dd:dd:dd:7703/1282c19:dd:c25:c25:dd:dd:dd:7703
52c19:dd:c25:c25:dd:dd:dd:7704/1282c19:dd:c25:c25:dd:dd:dd:7704
62c19:dd:c25:c25:dd:dd:dd:7705/1282c19:dd:c25:c25:dd:dd:dd:7705
72c19:dd:c25:c25:dd:dd:dd:7706/1282c19:dd:c25:c25:dd:dd:dd:7706
82c19:dd:c25:c25:dd:dd:dd:7707/1282c19:dd:c25:c25:dd:dd:dd:7707
92c19:dd:c25:c25:dd:dd:dd:7708/1282c19:dd:c25:c25:dd:dd:dd:7708
102c19:dd:c25:c25:dd:dd:dd:7709/1282c19:dd:c25:c25:dd:dd:dd:7709
112c19:dd:c25:c25:dd:dd:dd:770a/1282c19:dd:c25:c25:dd:dd:dd:770a
122c19:dd:c25:c25:dd:dd:dd:770b/1282c19:dd:c25:c25:dd:dd:dd:770b
132c19:dd:c25:c25:dd:dd:dd:770c/1282c19:dd:c25:c25:dd:dd:dd:770c
142c19:dd:c25:c25:dd:dd:dd:770d/1282c19:dd:c25:c25:dd:dd:dd:770d
152c19:dd:c25:c25:dd:dd:dd:770e/1282c19:dd:c25:c25:dd:dd:dd:770e
162c19:dd:c25:c25:dd:dd:dd:770f/1282c19:dd:c25:c25:dd:dd:dd:770f
172c19:dd:c25:c25:dd:dd:dd:7710/1282c19:dd:c25:c25:dd:dd:dd:7710
182c19:dd:c25:c25:dd:dd:dd:7711/1282c19:dd:c25:c25:dd:dd:dd:7711
192c19:dd:c25:c25:dd:dd:dd:7712/1282c19:dd:c25:c25:dd:dd:dd:7712
202c19:dd:c25:c25:dd:dd:dd:7713/1282c19:dd:c25:c25:dd:dd:dd:7713
212c19:dd:c25:c25:dd:dd:dd:7714/1282c19:dd:c25:c25:dd:dd:dd:7714
222c19:dd:c25:c25:dd:dd:dd:7715/1282c19:dd:c25:c25:dd:dd:dd:7715
232c19:dd:c25:c25:dd:dd:dd:7716/1282c19:dd:c25:c25:dd:dd:dd:7716
242c19:dd:c25:c25:dd:dd:dd:7717/1282c19:dd:c25:c25:dd:dd:dd:7717
252c19:dd:c25:c25:dd:dd:dd:7718/1282c19:dd:c25:c25:dd:dd:dd:7718
262c19:dd:c25:c25:dd:dd:dd:7719/1282c19:dd:c25:c25:dd:dd:dd:7719
272c19:dd:c25:c25:dd:dd:dd:771a/1282c19:dd:c25:c25:dd:dd:dd:771a
282c19:dd:c25:c25:dd:dd:dd:771b/1282c19:dd:c25:c25:dd:dd:dd:771b
292c19:dd:c25:c25:dd:dd:dd:771c/1282c19:dd:c25:c25:dd:dd:dd:771c
302c19:dd:c25:c25:dd:dd:dd:771d/1282c19:dd:c25:c25:dd:dd:dd:771d
312c19:dd:c25:c25:dd:dd:dd:771e/1282c19:dd:c25:c25:dd:dd:dd:771e
322c19:dd:c25:c25:dd:dd:dd:771f/1282c19:dd:c25:c25:dd:dd:dd:771f
332c19:dd:c25:c25:dd:dd:dd:7720/1282c19:dd:c25:c25:dd:dd:dd:7720
342c19:dd:c25:c25:dd:dd:dd:7721/1282c19:dd:c25:c25:dd:dd:dd:7721
352c19:dd:c25:c25:dd:dd:dd:7722/1282c19:dd:c25:c25:dd:dd:dd:7722
362c19:dd:c25:c25:dd:dd:dd:7723/1282c19:dd:c25:c25:dd:dd:dd:7723
372c19:dd:c25:c25:dd:dd:dd:7724/1282c19:dd:c25:c25:dd:dd:dd:7724
382c19:dd:c25:c25:dd:dd:dd:7725/1282c19:dd:c25:c25:dd:dd:dd:7725
392c19:dd:c25:c25:dd:dd:dd:7726/1282c19:dd:c25:c25:dd:dd:dd:7726
402c19:dd:c25:c25:dd:dd:dd:7727/1282c19:dd:c25:c25:dd:dd:dd:7727
412c19:dd:c25:c25:dd:dd:dd:7728/1282c19:dd:c25:c25:dd:dd:dd:7728
422c19:dd:c25:c25:dd:dd:dd:7729/1282c19:dd:c25:c25:dd:dd:dd:7729
432c19:dd:c25:c25:dd:dd:dd:772a/1282c19:dd:c25:c25:dd:dd:dd:772a
442c19:dd:c25:c25:dd:dd:dd:772b/1282c19:dd:c25:c25:dd:dd:dd:772b
452c19:dd:c25:c25:dd:dd:dd:772c/1282c19:dd:c25:c25:dd:dd:dd:772c
462c19:dd:c25:c25:dd:dd:dd:772d/1282c19:dd:c25:c25:dd:dd:dd:772d
472c19:dd:c25:c25:dd:dd:dd:772e/1282c19:dd:c25:c25:dd:dd:dd:772e
482c19:dd:c25:c25:dd:dd:dd:772f/1282c19:dd:c25:c25:dd:dd:dd:772f
492c19:dd:c25:c25:dd:dd:dd:7730/1282c19:dd:c25:c25:dd:dd:dd:7730
502c19:dd:c25:c25:dd:dd:dd:7731/1282c19:dd:c25:c25:dd:dd:dd:7731
512c19:dd:c25:c25:dd:dd:dd:7732/1282c19:dd:c25:c25:dd:dd:dd:7732
522c19:dd:c25:c25:dd:dd:dd:7733/1282c19:dd:c25:c25:dd:dd:dd:7733
532c19:dd:c25:c25:dd:dd:dd:7734/1282c19:dd:c25:c25:dd:dd:dd:7734
542c19:dd:c25:c25:dd:dd:dd:7735/1282c19:dd:c25:c25:dd:dd:dd:7735
552c19:dd:c25:c25:dd:dd:dd:7736/1282c19:dd:c25:c25:dd:dd:dd:7736
562c19:dd:c25:c25:dd:dd:dd:7737/1282c19:dd:c25:c25:dd:dd:dd:7737
572c19:dd:c25:c25:dd:dd:dd:7738/1282c19:dd:c25:c25:dd:dd:dd:7738
582c19:dd:c25:c25:dd:dd:dd:7739/1282c19:dd:c25:c25:dd:dd:dd:7739
592c19:dd:c25:c25:dd:dd:dd:773a/1282c19:dd:c25:c25:dd:dd:dd:773a
602c19:dd:c25:c25:dd:dd:dd:773b/1282c19:dd:c25:c25:dd:dd:dd:773b
612c19:dd:c25:c25:dd:dd:dd:773c/1282c19:dd:c25:c25:dd:dd:dd:773c
622c19:dd:c25:c25:dd:dd:dd:773d/1282c19:dd:c25:c25:dd:dd:dd:773d
632c19:dd:c25:c25:dd:dd:dd:773e/1282c19:dd:c25:c25:dd:dd:dd:773e
642c19:dd:c25:c25:dd:dd:dd:773f/1282c19:dd:c25:c25:dd:dd:dd:773f
652c19:dd:c25:c25:dd:dd:dd:7740/1282c19:dd:c25:c25:dd:dd:dd:7740
662c19:dd:c25:c25:dd:dd:dd:7741/1282c19:dd:c25:c25:dd:dd:dd:7741
672c19:dd:c25:c25:dd:dd:dd:7742/1282c19:dd:c25:c25:dd:dd:dd:7742
682c19:dd:c25:c25:dd:dd:dd:7743/1282c19:dd:c25:c25:dd:dd:dd:7743
692c19:dd:c25:c25:dd:dd:dd:7744/1282c19:dd:c25:c25:dd:dd:dd:7744
702c19:dd:c25:c25:dd:dd:dd:7745/1282c19:dd:c25:c25:dd:dd:dd:7745
712c19:dd:c25:c25:dd:dd:dd:7746/1282c19:dd:c25:c25:dd:dd:dd:7746
722c19:dd:c25:c25:dd:dd:dd:7747/1282c19:dd:c25:c25:dd:dd:dd:7747
732c19:dd:c25:c25:dd:dd:dd:7748/1282c19:dd:c25:c25:dd:dd:dd:7748
742c19:dd:c25:c25:dd:dd:dd:7749/1282c19:dd:c25:c25:dd:dd:dd:7749
752c19:dd:c25:c25:dd:dd:dd:774a/1282c19:dd:c25:c25:dd:dd:dd:774a
762c19:dd:c25:c25:dd:dd:dd:774b/1282c19:dd:c25:c25:dd:dd:dd:774b
772c19:dd:c25:c25:dd:dd:dd:774c/1282c19:dd:c25:c25:dd:dd:dd:774c
782c19:dd:c25:c25:dd:dd:dd:774d/1282c19:dd:c25:c25:dd:dd:dd:774d
792c19:dd:c25:c25:dd:dd:dd:774e/1282c19:dd:c25:c25:dd:dd:dd:774e
802c19:dd:c25:c25:dd:dd:dd:774f/1282c19:dd:c25:c25:dd:dd:dd:774f
812c19:dd:c25:c25:dd:dd:dd:7750/1282c19:dd:c25:c25:dd:dd:dd:7750
822c19:dd:c25:c25:dd:dd:dd:7751/1282c19:dd:c25:c25:dd:dd:dd:7751
832c19:dd:c25:c25:dd:dd:dd:7752/1282c19:dd:c25:c25:dd:dd:dd:7752
842c19:dd:c25:c25:dd:dd:dd:7753/1282c19:dd:c25:c25:dd:dd:dd:7753
852c19:dd:c25:c25:dd:dd:dd:7754/1282c19:dd:c25:c25:dd:dd:dd:7754
862c19:dd:c25:c25:dd:dd:dd:7755/1282c19:dd:c25:c25:dd:dd:dd:7755
872c19:dd:c25:c25:dd:dd:dd:7756/1282c19:dd:c25:c25:dd:dd:dd:7756
882c19:dd:c25:c25:dd:dd:dd:7757/1282c19:dd:c25:c25:dd:dd:dd:7757
892c19:dd:c25:c25:dd:dd:dd:7758/1282c19:dd:c25:c25:dd:dd:dd:7758
902c19:dd:c25:c25:dd:dd:dd:7759/1282c19:dd:c25:c25:dd:dd:dd:7759
912c19:dd:c25:c25:dd:dd:dd:775a/1282c19:dd:c25:c25:dd:dd:dd:775a
922c19:dd:c25:c25:dd:dd:dd:775b/1282c19:dd:c25:c25:dd:dd:dd:775b
932c19:dd:c25:c25:dd:dd:dd:775c/1282c19:dd:c25:c25:dd:dd:dd:775c
942c19:dd:c25:c25:dd:dd:dd:775d/1282c19:dd:c25:c25:dd:dd:dd:775d
952c19:dd:c25:c25:dd:dd:dd:775e/1282c19:dd:c25:c25:dd:dd:dd:775e
962c19:dd:c25:c25:dd:dd:dd:775f/1282c19:dd:c25:c25:dd:dd:dd:775f
972c19:dd:c25:c25:dd:dd:dd:7760/1282c19:dd:c25:c25:dd:dd:dd:7760
982c19:dd:c25:c25:dd:dd:dd:7761/1282c19:dd:c25:c25:dd:dd:dd:7761
992c19:dd:c25:c25:dd:dd:dd:7762/1282c19:dd:c25:c25:dd:dd:dd:7762
1002c19:dd:c25:c25:dd:dd:dd:7763/1282c19:dd:c25:c25:dd:dd:dd:7763
1012c19:dd:c25:c25:dd:dd:dd:7764/1282c19:dd:c25:c25:dd:dd:dd:7764
1022c19:dd:c25:c25:dd:dd:dd:7765/1282c19:dd:c25:c25:dd:dd:dd:7765
1032c19:dd:c25:c25:dd:dd:dd:7766/1282c19:dd:c25:c25:dd:dd:dd:7766
1042c19:dd:c25:c25:dd:dd:dd:7767/1282c19:dd:c25:c25:dd:dd:dd:7767
1052c19:dd:c25:c25:dd:dd:dd:7768/1282c19:dd:c25:c25:dd:dd:dd:7768
1062c19:dd:c25:c25:dd:dd:dd:7769/1282c19:dd:c25:c25:dd:dd:dd:7769
1072c19:dd:c25:c25:dd:dd:dd:776a/1282c19:dd:c25:c25:dd:dd:dd:776a
1082c19:dd:c25:c25:dd:dd:dd:776b/1282c19:dd:c25:c25:dd:dd:dd:776b
1092c19:dd:c25:c25:dd:dd:dd:776c/1282c19:dd:c25:c25:dd:dd:dd:776c
1102c19:dd:c25:c25:dd:dd:dd:776d/1282c19:dd:c25:c25:dd:dd:dd:776d
1112c19:dd:c25:c25:dd:dd:dd:776e/1282c19:dd:c25:c25:dd:dd:dd:776e
1122c19:dd:c25:c25:dd:dd:dd:776f/1282c19:dd:c25:c25:dd:dd:dd:776f
1132c19:dd:c25:c25:dd:dd:dd:7770/1282c19:dd:c25:c25:dd:dd:dd:7770
1142c19:dd:c25:c25:dd:dd:dd:7771/1282c19:dd:c25:c25:dd:dd:dd:7771
1152c19:dd:c25:c25:dd:dd:dd:7772/1282c19:dd:c25:c25:dd:dd:dd:7772
1162c19:dd:c25:c25:dd:dd:dd:7773/1282c19:dd:c25:c25:dd:dd:dd:7773
1172c19:dd:c25:c25:dd:dd:dd:7774/1282c19:dd:c25:c25:dd:dd:dd:7774
1182c19:dd:c25:c25:dd:dd:dd:7775/1282c19:dd:c25:c25:dd:dd:dd:7775
1192c19:dd:c25:c25:dd:dd:dd:7776/1282c19:dd:c25:c25:dd:dd:dd:7776
1202c19:dd:c25:c25:dd:dd:dd:7777/1282c19:dd:c25:c25:dd:dd:dd:7777
1212c19:dd:c25:c25:dd:dd:dd:7778/1282c19:dd:c25:c25:dd:dd:dd:7778
1222c19:dd:c25:c25:dd:dd:dd:7779/1282c19:dd:c25:c25:dd:dd:dd:7779
1232c19:dd:c25:c25:dd:dd:dd:777a/1282c19:dd:c25:c25:dd:dd:dd:777a
1242c19:dd:c25:c25:dd:dd:dd:777b/1282c19:dd:c25:c25:dd:dd:dd:777b
1252c19:dd:c25:c25:dd:dd:dd:777c/1282c19:dd:c25:c25:dd:dd:dd:777c
1262c19:dd:c25:c25:dd:dd:dd:777d/1282c19:dd:c25:c25:dd:dd:dd:777d
1272c19:dd:c25:c25:dd:dd:dd:777e/1282c19:dd:c25:c25:dd:dd:dd:777e
1282c19:dd:c25:c25:dd:dd:dd:777f/1282c19:dd:c25:c25:dd:dd:dd:777f
1292c19:dd:c25:c25:dd:dd:dd:7780/1282c19:dd:c25:c25:dd:dd:dd:7780
1302c19:dd:c25:c25:dd:dd:dd:7781/1282c19:dd:c25:c25:dd:dd:dd:7781
1312c19:dd:c25:c25:dd:dd:dd:7782/1282c19:dd:c25:c25:dd:dd:dd:7782
1322c19:dd:c25:c25:dd:dd:dd:7783/1282c19:dd:c25:c25:dd:dd:dd:7783
1332c19:dd:c25:c25:dd:dd:dd:7784/1282c19:dd:c25:c25:dd:dd:dd:7784
1342c19:dd:c25:c25:dd:dd:dd:7785/1282c19:dd:c25:c25:dd:dd:dd:7785
1352c19:dd:c25:c25:dd:dd:dd:7786/1282c19:dd:c25:c25:dd:dd:dd:7786
1362c19:dd:c25:c25:dd:dd:dd:7787/1282c19:dd:c25:c25:dd:dd:dd:7787
1372c19:dd:c25:c25:dd:dd:dd:7788/1282c19:dd:c25:c25:dd:dd:dd:7788
1382c19:dd:c25:c25:dd:dd:dd:7789/1282c19:dd:c25:c25:dd:dd:dd:7789
1392c19:dd:c25:c25:dd:dd:dd:778a/1282c19:dd:c25:c25:dd:dd:dd:778a
1402c19:dd:c25:c25:dd:dd:dd:778b/1282c19:dd:c25:c25:dd:dd:dd:778b
1412c19:dd:c25:c25:dd:dd:dd:778c/1282c19:dd:c25:c25:dd:dd:dd:778c
1422c19:dd:c25:c25:dd:dd:dd:778d/1282c19:dd:c25:c25:dd:dd:dd:778d
1432c19:dd:c25:c25:dd:dd:dd:778e/1282c19:dd:c25:c25:dd:dd:dd:778e
1442c19:dd:c25:c25:dd:dd:dd:778f/1282c19:dd:c25:c25:dd:dd:dd:778f
1452c19:dd:c25:c25:dd:dd:dd:7790/1282c19:dd:c25:c25:dd:dd:dd:7790
1462c19:dd:c25:c25:dd:dd:dd:7791/1282c19:dd:c25:c25:dd:dd:dd:7791
1472c19:dd:c25:c25:dd:dd:dd:7792/1282c19:dd:c25:c25:dd:dd:dd:7792
1482c19:dd:c25:c25:dd:dd:dd:7793/1282c19:dd:c25:c25:dd:dd:dd:7793
1492c19:dd:c25:c25:dd:dd:dd:7794/1282c19:dd:c25:c25:dd:dd:dd:7794
1502c19:dd:c25:c25:dd:dd:dd:7795/1282c19:dd:c25:c25:dd:dd:dd:7795
1512c19:dd:c25:c25:dd:dd:dd:7796/1282c19:dd:c25:c25:dd:dd:dd:7796
1522c19:dd:c25:c25:dd:dd:dd:7797/1282c19:dd:c25:c25:dd:dd:dd:7797
1532c19:dd:c25:c25:dd:dd:dd:7798/1282c19:dd:c25:c25:dd:dd:dd:7798
1542c19:dd:c25:c25:dd:dd:dd:7799/1282c19:dd:c25:c25:dd:dd:dd:7799
1552c19:dd:c25:c25:dd:dd:dd:779a/1282c19:dd:c25:c25:dd:dd:dd:779a
1562c19:dd:c25:c25:dd:dd:dd:779b/1282c19:dd:c25:c25:dd:dd:dd:779b
1572c19:dd:c25:c25:dd:dd:dd:779c/1282c19:dd:c25:c25:dd:dd:dd:779c
1582c19:dd:c25:c25:dd:dd:dd:779d/1282c19:dd:c25:c25:dd:dd:dd:779d
1592c19:dd:c25:c25:dd:dd:dd:779e/1282c19:dd:c25:c25:dd:dd:dd:779e
1602c19:dd:c25:c25:dd:dd:dd:779f/1282c19:dd:c25:c25:dd:dd:dd:779f
1612c19:dd:c25:c25:dd:dd:dd:77a0/1282c19:dd:c25:c25:dd:dd:dd:77a0
1622c19:dd:c25:c25:dd:dd:dd:77a1/1282c19:dd:c25:c25:dd:dd:dd:77a1
1632c19:dd:c25:c25:dd:dd:dd:77a2/1282c19:dd:c25:c25:dd:dd:dd:77a2
1642c19:dd:c25:c25:dd:dd:dd:77a3/1282c19:dd:c25:c25:dd:dd:dd:77a3
1652c19:dd:c25:c25:dd:dd:dd:77a4/1282c19:dd:c25:c25:dd:dd:dd:77a4
1662c19:dd:c25:c25:dd:dd:dd:77a5/1282c19:dd:c25:c25:dd:dd:dd:77a5
1672c19:dd:c25:c25:dd:dd:dd:77a6/1282c19:dd:c25:c25:dd:dd:dd:77a6
1682c19:dd:c25:c25:dd:dd:dd:77a7/1282c19:dd:c25:c25:dd:dd:dd:77a7
1692c19:dd:c25:c25:dd:dd:dd:77a8/1282c19:dd:c25:c25:dd:dd:dd:77a8
1702c19:dd:c25:c25:dd:dd:dd:77a9/1282c19:dd:c25:c25:dd:dd:dd:77a9
1712c19:dd:c25:c25:dd:dd:dd:77aa/1282c19:dd:c25:c25:dd:dd:dd:77aa
1722c19:dd:c25:c25:dd:dd:dd:77ab/1282c19:dd:c25:c25:dd:dd:dd:77ab
1732c19:dd:c25:c25:dd:dd:dd:77ac/1282c19:dd:c25:c25:dd:dd:dd:77ac
1742c19:dd:c25:c25:dd:dd:dd:77ad/1282c19:dd:c25:c25:dd:dd:dd:77ad
1752c19:dd:c25:c25:dd:dd:dd:77ae/1282c19:dd:c25:c25:dd:dd:dd:77ae
1762c19:dd:c25:c25:dd:dd:dd:77af/1282c19:dd:c25:c25:dd:dd:dd:77af
1772c19:dd:c25:c25:dd:dd:dd:77b0/1282c19:dd:c25:c25:dd:dd:dd:77b0
1782c19:dd:c25:c25:dd:dd:dd:77b1/1282c19:dd:c25:c25:dd:dd:dd:77b1
1792c19:dd:c25:c25:dd:dd:dd:77b2/1282c19:dd:c25:c25:dd:dd:dd:77b2
1802c19:dd:c25:c25:dd:dd:dd:77b3/1282c19:dd:c25:c25:dd:dd:dd:77b3
1812c19:dd:c25:c25:dd:dd:dd:77b4/1282c19:dd:c25:c25:dd:dd:dd:77b4
1822c19:dd:c25:c25:dd:dd:dd:77b5/1282c19:dd:c25:c25:dd:dd:dd:77b5
1832c19:dd:c25:c25:dd:dd:dd:77b6/1282c19:dd:c25:c25:dd:dd:dd:77b6
1842c19:dd:c25:c25:dd:dd:dd:77b7/1282c19:dd:c25:c25:dd:dd:dd:77b7
1852c19:dd:c25:c25:dd:dd:dd:77b8/1282c19:dd:c25:c25:dd:dd:dd:77b8
1862c19:dd:c25:c25:dd:dd:dd:77b9/1282c19:dd:c25:c25:dd:dd:dd:77b9
1872c19:dd:c25:c25:dd:dd:dd:77ba/1282c19:dd:c25:c25:dd:dd:dd:77ba
1882c19:dd:c25:c25:dd:dd:dd:77bb/1282c19:dd:c25:c25:dd:dd:dd:77bb
1892c19:dd:c25:c25:dd:dd:dd:77bc/1282c19:dd:c25:c25:dd:dd:dd:77bc
1902c19:dd:c25:c25:dd:dd:dd:77bd/1282c19:dd:c25:c25:dd:dd:dd:77bd
1912c19:dd:c25:c25:dd:dd:dd:77be/1282c19:dd:c25:c25:dd:dd:dd:77be
1922c19:dd:c25:c25:dd:dd:dd:77bf/1282c19:dd:c25:c25:dd:dd:dd:77bf
1932c19:dd:c25:c25:dd:dd:dd:77c0/1282c19:dd:c25:c25:dd:dd:dd:77c0
1942c19:dd:c25:c25:dd:dd:dd:77c1/1282c19:dd:c25:c25:dd:dd:dd:77c1
1952c19:dd:c25:c25:dd:dd:dd:77c2/1282c19:dd:c25:c25:dd:dd:dd:77c2
1962c19:dd:c25:c25:dd:dd:dd:77c3/1282c19:dd:c25:c25:dd:dd:dd:77c3
1972c19:dd:c25:c25:dd:dd:dd:77c4/1282c19:dd:c25:c25:dd:dd:dd:77c4
1982c19:dd:c25:c25:dd:dd:dd:77c5/1282c19:dd:c25:c25:dd:dd:dd:77c5
1992c19:dd:c25:c25:dd:dd:dd:77c6/1282c19:dd:c25:c25:dd:dd:dd:77c6
2002c19:dd:c25:c25:dd:dd:dd:77c7/1282c19:dd:c25:c25:dd:dd:dd:77c7
2012c19:dd:c25:c25:dd:dd:dd:77c8/1282c19:dd:c25:c25:dd:dd:dd:77c8
2022c19:dd:c25:c25:dd:dd:dd:77c9/1282c19:dd:c25:c25:dd:dd:dd:77c9
2032c19:dd:c25:c25:dd:dd:dd:77ca/1282c19:dd:c25:c25:dd:dd:dd:77ca
2042c19:dd:c25:c25:dd:dd:dd:77cb/1282c19:dd:c25:c25:dd:dd:dd:77cb
2052c19:dd:c25:c25:dd:dd:dd:77cc/1282c19:dd:c25:c25:dd:dd:dd:77cc
2062c19:dd:c25:c25:dd:dd:dd:77cd/1282c19:dd:c25:c25:dd:dd:dd:77cd
2072c19:dd:c25:c25:dd:dd:dd:77ce/1282c19:dd:c25:c25:dd:dd:dd:77ce
2082c19:dd:c25:c25:dd:dd:dd:77cf/1282c19:dd:c25:c25:dd:dd:dd:77cf
2092c19:dd:c25:c25:dd:dd:dd:77d0/1282c19:dd:c25:c25:dd:dd:dd:77d0
2102c19:dd:c25:c25:dd:dd:dd:77d1/1282c19:dd:c25:c25:dd:dd:dd:77d1
2112c19:dd:c25:c25:dd:dd:dd:77d2/1282c19:dd:c25:c25:dd:dd:dd:77d2
2122c19:dd:c25:c25:dd:dd:dd:77d3/1282c19:dd:c25:c25:dd:dd:dd:77d3
2132c19:dd:c25:c25:dd:dd:dd:77d4/1282c19:dd:c25:c25:dd:dd:dd:77d4
2142c19:dd:c25:c25:dd:dd:dd:77d5/1282c19:dd:c25:c25:dd:dd:dd:77d5
2152c19:dd:c25:c25:dd:dd:dd:77d6/1282c19:dd:c25:c25:dd:dd:dd:77d6
2162c19:dd:c25:c25:dd:dd:dd:77d7/1282c19:dd:c25:c25:dd:dd:dd:77d7
2172c19:dd:c25:c25:dd:dd:dd:77d8/1282c19:dd:c25:c25:dd:dd:dd:77d8
2182c19:dd:c25:c25:dd:dd:dd:77d9/1282c19:dd:c25:c25:dd:dd:dd:77d9
2192c19:dd:c25:c25:dd:dd:dd:77da/1282c19:dd:c25:c25:dd:dd:dd:77da
2202c19:dd:c25:c25:dd:dd:dd:77db/1282c19:dd:c25:c25:dd:dd:dd:77db
2212c19:dd:c25:c25:dd:dd:dd:77dc/1282c19:dd:c25:c25:dd:dd:dd:77dc
2222c19:dd:c25:c25:dd:dd:dd:77dd/1282c19:dd:c25:c25:dd:dd:dd:77dd
2232c19:dd:c25:c25:dd:dd:dd:77de/1282c19:dd:c25:c25:dd:dd:dd:77de
2242c19:dd:c25:c25:dd:dd:dd:77df/1282c19:dd:c25:c25:dd:dd:dd:77df
2252c19:dd:c25:c25:dd:dd:dd:77e0/1282c19:dd:c25:c25:dd:dd:dd:77e0
2262c19:dd:c25:c25:dd:dd:dd:77e1/1282c19:dd:c25:c25:dd:dd:dd:77e1
2272c19:dd:c25:c25:dd:dd:dd:77e2/1282c19:dd:c25:c25:dd:dd:dd:77e2
2282c19:dd:c25:c25:dd:dd:dd:77e3/1282c19:dd:c25:c25:dd:dd:dd:77e3
2292c19:dd:c25:c25:dd:dd:dd:77e4/1282c19:dd:c25:c25:dd:dd:dd:77e4
2302c19:dd:c25:c25:dd:dd:dd:77e5/1282c19:dd:c25:c25:dd:dd:dd:77e5
2312c19:dd:c25:c25:dd:dd:dd:77e6/1282c19:dd:c25:c25:dd:dd:dd:77e6
2322c19:dd:c25:c25:dd:dd:dd:77e7/1282c19:dd:c25:c25:dd:dd:dd:77e7
2332c19:dd:c25:c25:dd:dd:dd:77e8/1282c19:dd:c25:c25:dd:dd:dd:77e8
2342c19:dd:c25:c25:dd:dd:dd:77e9/1282c19:dd:c25:c25:dd:dd:dd:77e9
2352c19:dd:c25:c25:dd:dd:dd:77ea/1282c19:dd:c25:c25:dd:dd:dd:77ea
2362c19:dd:c25:c25:dd:dd:dd:77eb/1282c19:dd:c25:c25:dd:dd:dd:77eb
2372c19:dd:c25:c25:dd:dd:dd:77ec/1282c19:dd:c25:c25:dd:dd:dd:77ec
2382c19:dd:c25:c25:dd:dd:dd:77ed/1282c19:dd:c25:c25:dd:dd:dd:77ed
2392c19:dd:c25:c25:dd:dd:dd:77ee/1282c19:dd:c25:c25:dd:dd:dd:77ee
2402c19:dd:c25:c25:dd:dd:dd:77ef/1282c19:dd:c25:c25:dd:dd:dd:77ef
2412c19:dd:c25:c25:dd:dd:dd:77f0/1282c19:dd:c25:c25:dd:dd:dd:77f0
2422c19:dd:c25:c25:dd:dd:dd:77f1/1282c19:dd:c25:c25:dd:dd:dd:77f1
2432c19:dd:c25:c25:dd:dd:dd:77f2/1282c19:dd:c25:c25:dd:dd:dd:77f2
2442c19:dd:c25:c25:dd:dd:dd:77f3/1282c19:dd:c25:c25:dd:dd:dd:77f3
2452c19:dd:c25:c25:dd:dd:dd:77f4/1282c19:dd:c25:c25:dd:dd:dd:77f4
2462c19:dd:c25:c25:dd:dd:dd:77f5/1282c19:dd:c25:c25:dd:dd:dd:77f5
2472c19:dd:c25:c25:dd:dd:dd:77f6/1282c19:dd:c25:c25:dd:dd:dd:77f6
2482c19:dd:c25:c25:dd:dd:dd:77f7/1282c19:dd:c25:c25:dd:dd:dd:77f7
2492c19:dd:c25:c25:dd:dd:dd:77f8/1282c19:dd:c25:c25:dd:dd:dd:77f8
2502c19:dd:c25:c25:dd:dd:dd:77f9/1282c19:dd:c25:c25:dd:dd:dd:77f9
2512c19:dd:c25:c25:dd:dd:dd:77fa/1282c19:dd:c25:c25:dd:dd:dd:77fa
2522c19:dd:c25:c25:dd:dd:dd:77fb/1282c19:dd:c25:c25:dd:dd:dd:77fb
2532c19:dd:c25:c25:dd:dd:dd:77fc/1282c19:dd:c25:c25:dd:dd:dd:77fc
2542c19:dd:c25:c25:dd:dd:dd:77fd/1282c19:dd:c25:c25:dd:dd:dd:77fd
2552c19:dd:c25:c25:dd:dd:dd:77fe/1282c19:dd:c25:c25:dd:dd:dd:77fe
2562c19:dd:c25:c25:dd:dd:dd:77ff/1282c19:dd:c25:c25:dd:dd:dd:77ff

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.