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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/118
Addresses1,024
/64 networksPart of one
Network
2c19:dd:c25:c25d:dd:dd:dd:800/118
First address
2c19:dd:c25:c25d:dd:dd:dd:800
Last address
2c19:dd:c25:c25d:dd:dd:dd:bff
Addresses
1,024
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:0c25:c25d:00dd:00dd:00dd:0800
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zones
8.0.d.d.0.0.d.d.0.0.d.d.0.0.d.5.2.c.5.2.c.0.d.d.0.0.9.1.c.2.ip6.arpa
9.0.d.d.0.0.d.d.0.0.d.d.0.0.d.5.2.c.5.2.c.0.d.d.0.0.9.1.c.2.ip6.arpa
a.0.d.d.0.0.d.d.0.0.d.d.0.0.d.5.2.c.5.2.c.0.d.d.0.0.9.1.c.2.ip6.arpa
b.0.d.d.0.0.d.d.0.0.d.d.0.0.d.5.2.c.5.2.c.0.d.d.0.0.9.1.c.2.ip6.arpa
/118 is not on a 4-bit boundary, so it takes 4 /120 zones.
Split into smaller subnets/127
/119 (2)/120 (4)/121 (8)/122 (16)/124 (64)/127 (512)/128 (1,024)

2c19:dd:c25:c25d:dd:dd:dd:800/118 makes 512 subnets of /127; the first 256 are listed.

Subnets
#SubnetLast address
12c19:dd:c25:c25d:dd:dd:dd:800/1272c19:dd:c25:c25d:dd:dd:dd:801
22c19:dd:c25:c25d:dd:dd:dd:802/1272c19:dd:c25:c25d:dd:dd:dd:803
32c19:dd:c25:c25d:dd:dd:dd:804/1272c19:dd:c25:c25d:dd:dd:dd:805
42c19:dd:c25:c25d:dd:dd:dd:806/1272c19:dd:c25:c25d:dd:dd:dd:807
52c19:dd:c25:c25d:dd:dd:dd:808/1272c19:dd:c25:c25d:dd:dd:dd:809
62c19:dd:c25:c25d:dd:dd:dd:80a/1272c19:dd:c25:c25d:dd:dd:dd:80b
72c19:dd:c25:c25d:dd:dd:dd:80c/1272c19:dd:c25:c25d:dd:dd:dd:80d
82c19:dd:c25:c25d:dd:dd:dd:80e/1272c19:dd:c25:c25d:dd:dd:dd:80f
92c19:dd:c25:c25d:dd:dd:dd:810/1272c19:dd:c25:c25d:dd:dd:dd:811
102c19:dd:c25:c25d:dd:dd:dd:812/1272c19:dd:c25:c25d:dd:dd:dd:813
112c19:dd:c25:c25d:dd:dd:dd:814/1272c19:dd:c25:c25d:dd:dd:dd:815
122c19:dd:c25:c25d:dd:dd:dd:816/1272c19:dd:c25:c25d:dd:dd:dd:817
132c19:dd:c25:c25d:dd:dd:dd:818/1272c19:dd:c25:c25d:dd:dd:dd:819
142c19:dd:c25:c25d:dd:dd:dd:81a/1272c19:dd:c25:c25d:dd:dd:dd:81b
152c19:dd:c25:c25d:dd:dd:dd:81c/1272c19:dd:c25:c25d:dd:dd:dd:81d
162c19:dd:c25:c25d:dd:dd:dd:81e/1272c19:dd:c25:c25d:dd:dd:dd:81f
172c19:dd:c25:c25d:dd:dd:dd:820/1272c19:dd:c25:c25d:dd:dd:dd:821
182c19:dd:c25:c25d:dd:dd:dd:822/1272c19:dd:c25:c25d:dd:dd:dd:823
192c19:dd:c25:c25d:dd:dd:dd:824/1272c19:dd:c25:c25d:dd:dd:dd:825
202c19:dd:c25:c25d:dd:dd:dd:826/1272c19:dd:c25:c25d:dd:dd:dd:827
212c19:dd:c25:c25d:dd:dd:dd:828/1272c19:dd:c25:c25d:dd:dd:dd:829
222c19:dd:c25:c25d:dd:dd:dd:82a/1272c19:dd:c25:c25d:dd:dd:dd:82b
232c19:dd:c25:c25d:dd:dd:dd:82c/1272c19:dd:c25:c25d:dd:dd:dd:82d
242c19:dd:c25:c25d:dd:dd:dd:82e/1272c19:dd:c25:c25d:dd:dd:dd:82f
252c19:dd:c25:c25d:dd:dd:dd:830/1272c19:dd:c25:c25d:dd:dd:dd:831
262c19:dd:c25:c25d:dd:dd:dd:832/1272c19:dd:c25:c25d:dd:dd:dd:833
272c19:dd:c25:c25d:dd:dd:dd:834/1272c19:dd:c25:c25d:dd:dd:dd:835
282c19:dd:c25:c25d:dd:dd:dd:836/1272c19:dd:c25:c25d:dd:dd:dd:837
292c19:dd:c25:c25d:dd:dd:dd:838/1272c19:dd:c25:c25d:dd:dd:dd:839
302c19:dd:c25:c25d:dd:dd:dd:83a/1272c19:dd:c25:c25d:dd:dd:dd:83b
312c19:dd:c25:c25d:dd:dd:dd:83c/1272c19:dd:c25:c25d:dd:dd:dd:83d
322c19:dd:c25:c25d:dd:dd:dd:83e/1272c19:dd:c25:c25d:dd:dd:dd:83f
332c19:dd:c25:c25d:dd:dd:dd:840/1272c19:dd:c25:c25d:dd:dd:dd:841
342c19:dd:c25:c25d:dd:dd:dd:842/1272c19:dd:c25:c25d:dd:dd:dd:843
352c19:dd:c25:c25d:dd:dd:dd:844/1272c19:dd:c25:c25d:dd:dd:dd:845
362c19:dd:c25:c25d:dd:dd:dd:846/1272c19:dd:c25:c25d:dd:dd:dd:847
372c19:dd:c25:c25d:dd:dd:dd:848/1272c19:dd:c25:c25d:dd:dd:dd:849
382c19:dd:c25:c25d:dd:dd:dd:84a/1272c19:dd:c25:c25d:dd:dd:dd:84b
392c19:dd:c25:c25d:dd:dd:dd:84c/1272c19:dd:c25:c25d:dd:dd:dd:84d
402c19:dd:c25:c25d:dd:dd:dd:84e/1272c19:dd:c25:c25d:dd:dd:dd:84f
412c19:dd:c25:c25d:dd:dd:dd:850/1272c19:dd:c25:c25d:dd:dd:dd:851
422c19:dd:c25:c25d:dd:dd:dd:852/1272c19:dd:c25:c25d:dd:dd:dd:853
432c19:dd:c25:c25d:dd:dd:dd:854/1272c19:dd:c25:c25d:dd:dd:dd:855
442c19:dd:c25:c25d:dd:dd:dd:856/1272c19:dd:c25:c25d:dd:dd:dd:857
452c19:dd:c25:c25d:dd:dd:dd:858/1272c19:dd:c25:c25d:dd:dd:dd:859
462c19:dd:c25:c25d:dd:dd:dd:85a/1272c19:dd:c25:c25d:dd:dd:dd:85b
472c19:dd:c25:c25d:dd:dd:dd:85c/1272c19:dd:c25:c25d:dd:dd:dd:85d
482c19:dd:c25:c25d:dd:dd:dd:85e/1272c19:dd:c25:c25d:dd:dd:dd:85f
492c19:dd:c25:c25d:dd:dd:dd:860/1272c19:dd:c25:c25d:dd:dd:dd:861
502c19:dd:c25:c25d:dd:dd:dd:862/1272c19:dd:c25:c25d:dd:dd:dd:863
512c19:dd:c25:c25d:dd:dd:dd:864/1272c19:dd:c25:c25d:dd:dd:dd:865
522c19:dd:c25:c25d:dd:dd:dd:866/1272c19:dd:c25:c25d:dd:dd:dd:867
532c19:dd:c25:c25d:dd:dd:dd:868/1272c19:dd:c25:c25d:dd:dd:dd:869
542c19:dd:c25:c25d:dd:dd:dd:86a/1272c19:dd:c25:c25d:dd:dd:dd:86b
552c19:dd:c25:c25d:dd:dd:dd:86c/1272c19:dd:c25:c25d:dd:dd:dd:86d
562c19:dd:c25:c25d:dd:dd:dd:86e/1272c19:dd:c25:c25d:dd:dd:dd:86f
572c19:dd:c25:c25d:dd:dd:dd:870/1272c19:dd:c25:c25d:dd:dd:dd:871
582c19:dd:c25:c25d:dd:dd:dd:872/1272c19:dd:c25:c25d:dd:dd:dd:873
592c19:dd:c25:c25d:dd:dd:dd:874/1272c19:dd:c25:c25d:dd:dd:dd:875
602c19:dd:c25:c25d:dd:dd:dd:876/1272c19:dd:c25:c25d:dd:dd:dd:877
612c19:dd:c25:c25d:dd:dd:dd:878/1272c19:dd:c25:c25d:dd:dd:dd:879
622c19:dd:c25:c25d:dd:dd:dd:87a/1272c19:dd:c25:c25d:dd:dd:dd:87b
632c19:dd:c25:c25d:dd:dd:dd:87c/1272c19:dd:c25:c25d:dd:dd:dd:87d
642c19:dd:c25:c25d:dd:dd:dd:87e/1272c19:dd:c25:c25d:dd:dd:dd:87f
652c19:dd:c25:c25d:dd:dd:dd:880/1272c19:dd:c25:c25d:dd:dd:dd:881
662c19:dd:c25:c25d:dd:dd:dd:882/1272c19:dd:c25:c25d:dd:dd:dd:883
672c19:dd:c25:c25d:dd:dd:dd:884/1272c19:dd:c25:c25d:dd:dd:dd:885
682c19:dd:c25:c25d:dd:dd:dd:886/1272c19:dd:c25:c25d:dd:dd:dd:887
692c19:dd:c25:c25d:dd:dd:dd:888/1272c19:dd:c25:c25d:dd:dd:dd:889
702c19:dd:c25:c25d:dd:dd:dd:88a/1272c19:dd:c25:c25d:dd:dd:dd:88b
712c19:dd:c25:c25d:dd:dd:dd:88c/1272c19:dd:c25:c25d:dd:dd:dd:88d
722c19:dd:c25:c25d:dd:dd:dd:88e/1272c19:dd:c25:c25d:dd:dd:dd:88f
732c19:dd:c25:c25d:dd:dd:dd:890/1272c19:dd:c25:c25d:dd:dd:dd:891
742c19:dd:c25:c25d:dd:dd:dd:892/1272c19:dd:c25:c25d:dd:dd:dd:893
752c19:dd:c25:c25d:dd:dd:dd:894/1272c19:dd:c25:c25d:dd:dd:dd:895
762c19:dd:c25:c25d:dd:dd:dd:896/1272c19:dd:c25:c25d:dd:dd:dd:897
772c19:dd:c25:c25d:dd:dd:dd:898/1272c19:dd:c25:c25d:dd:dd:dd:899
782c19:dd:c25:c25d:dd:dd:dd:89a/1272c19:dd:c25:c25d:dd:dd:dd:89b
792c19:dd:c25:c25d:dd:dd:dd:89c/1272c19:dd:c25:c25d:dd:dd:dd:89d
802c19:dd:c25:c25d:dd:dd:dd:89e/1272c19:dd:c25:c25d:dd:dd:dd:89f
812c19:dd:c25:c25d:dd:dd:dd:8a0/1272c19:dd:c25:c25d:dd:dd:dd:8a1
822c19:dd:c25:c25d:dd:dd:dd:8a2/1272c19:dd:c25:c25d:dd:dd:dd:8a3
832c19:dd:c25:c25d:dd:dd:dd:8a4/1272c19:dd:c25:c25d:dd:dd:dd:8a5
842c19:dd:c25:c25d:dd:dd:dd:8a6/1272c19:dd:c25:c25d:dd:dd:dd:8a7
852c19:dd:c25:c25d:dd:dd:dd:8a8/1272c19:dd:c25:c25d:dd:dd:dd:8a9
862c19:dd:c25:c25d:dd:dd:dd:8aa/1272c19:dd:c25:c25d:dd:dd:dd:8ab
872c19:dd:c25:c25d:dd:dd:dd:8ac/1272c19:dd:c25:c25d:dd:dd:dd:8ad
882c19:dd:c25:c25d:dd:dd:dd:8ae/1272c19:dd:c25:c25d:dd:dd:dd:8af
892c19:dd:c25:c25d:dd:dd:dd:8b0/1272c19:dd:c25:c25d:dd:dd:dd:8b1
902c19:dd:c25:c25d:dd:dd:dd:8b2/1272c19:dd:c25:c25d:dd:dd:dd:8b3
912c19:dd:c25:c25d:dd:dd:dd:8b4/1272c19:dd:c25:c25d:dd:dd:dd:8b5
922c19:dd:c25:c25d:dd:dd:dd:8b6/1272c19:dd:c25:c25d:dd:dd:dd:8b7
932c19:dd:c25:c25d:dd:dd:dd:8b8/1272c19:dd:c25:c25d:dd:dd:dd:8b9
942c19:dd:c25:c25d:dd:dd:dd:8ba/1272c19:dd:c25:c25d:dd:dd:dd:8bb
952c19:dd:c25:c25d:dd:dd:dd:8bc/1272c19:dd:c25:c25d:dd:dd:dd:8bd
962c19:dd:c25:c25d:dd:dd:dd:8be/1272c19:dd:c25:c25d:dd:dd:dd:8bf
972c19:dd:c25:c25d:dd:dd:dd:8c0/1272c19:dd:c25:c25d:dd:dd:dd:8c1
982c19:dd:c25:c25d:dd:dd:dd:8c2/1272c19:dd:c25:c25d:dd:dd:dd:8c3
992c19:dd:c25:c25d:dd:dd:dd:8c4/1272c19:dd:c25:c25d:dd:dd:dd:8c5
1002c19:dd:c25:c25d:dd:dd:dd:8c6/1272c19:dd:c25:c25d:dd:dd:dd:8c7
1012c19:dd:c25:c25d:dd:dd:dd:8c8/1272c19:dd:c25:c25d:dd:dd:dd:8c9
1022c19:dd:c25:c25d:dd:dd:dd:8ca/1272c19:dd:c25:c25d:dd:dd:dd:8cb
1032c19:dd:c25:c25d:dd:dd:dd:8cc/1272c19:dd:c25:c25d:dd:dd:dd:8cd
1042c19:dd:c25:c25d:dd:dd:dd:8ce/1272c19:dd:c25:c25d:dd:dd:dd:8cf
1052c19:dd:c25:c25d:dd:dd:dd:8d0/1272c19:dd:c25:c25d:dd:dd:dd:8d1
1062c19:dd:c25:c25d:dd:dd:dd:8d2/1272c19:dd:c25:c25d:dd:dd:dd:8d3
1072c19:dd:c25:c25d:dd:dd:dd:8d4/1272c19:dd:c25:c25d:dd:dd:dd:8d5
1082c19:dd:c25:c25d:dd:dd:dd:8d6/1272c19:dd:c25:c25d:dd:dd:dd:8d7
1092c19:dd:c25:c25d:dd:dd:dd:8d8/1272c19:dd:c25:c25d:dd:dd:dd:8d9
1102c19:dd:c25:c25d:dd:dd:dd:8da/1272c19:dd:c25:c25d:dd:dd:dd:8db
1112c19:dd:c25:c25d:dd:dd:dd:8dc/1272c19:dd:c25:c25d:dd:dd:dd:8dd
1122c19:dd:c25:c25d:dd:dd:dd:8de/1272c19:dd:c25:c25d:dd:dd:dd:8df
1132c19:dd:c25:c25d:dd:dd:dd:8e0/1272c19:dd:c25:c25d:dd:dd:dd:8e1
1142c19:dd:c25:c25d:dd:dd:dd:8e2/1272c19:dd:c25:c25d:dd:dd:dd:8e3
1152c19:dd:c25:c25d:dd:dd:dd:8e4/1272c19:dd:c25:c25d:dd:dd:dd:8e5
1162c19:dd:c25:c25d:dd:dd:dd:8e6/1272c19:dd:c25:c25d:dd:dd:dd:8e7
1172c19:dd:c25:c25d:dd:dd:dd:8e8/1272c19:dd:c25:c25d:dd:dd:dd:8e9
1182c19:dd:c25:c25d:dd:dd:dd:8ea/1272c19:dd:c25:c25d:dd:dd:dd:8eb
1192c19:dd:c25:c25d:dd:dd:dd:8ec/1272c19:dd:c25:c25d:dd:dd:dd:8ed
1202c19:dd:c25:c25d:dd:dd:dd:8ee/1272c19:dd:c25:c25d:dd:dd:dd:8ef
1212c19:dd:c25:c25d:dd:dd:dd:8f0/1272c19:dd:c25:c25d:dd:dd:dd:8f1
1222c19:dd:c25:c25d:dd:dd:dd:8f2/1272c19:dd:c25:c25d:dd:dd:dd:8f3
1232c19:dd:c25:c25d:dd:dd:dd:8f4/1272c19:dd:c25:c25d:dd:dd:dd:8f5
1242c19:dd:c25:c25d:dd:dd:dd:8f6/1272c19:dd:c25:c25d:dd:dd:dd:8f7
1252c19:dd:c25:c25d:dd:dd:dd:8f8/1272c19:dd:c25:c25d:dd:dd:dd:8f9
1262c19:dd:c25:c25d:dd:dd:dd:8fa/1272c19:dd:c25:c25d:dd:dd:dd:8fb
1272c19:dd:c25:c25d:dd:dd:dd:8fc/1272c19:dd:c25:c25d:dd:dd:dd:8fd
1282c19:dd:c25:c25d:dd:dd:dd:8fe/1272c19:dd:c25:c25d:dd:dd:dd:8ff
1292c19:dd:c25:c25d:dd:dd:dd:900/1272c19:dd:c25:c25d:dd:dd:dd:901
1302c19:dd:c25:c25d:dd:dd:dd:902/1272c19:dd:c25:c25d:dd:dd:dd:903
1312c19:dd:c25:c25d:dd:dd:dd:904/1272c19:dd:c25:c25d:dd:dd:dd:905
1322c19:dd:c25:c25d:dd:dd:dd:906/1272c19:dd:c25:c25d:dd:dd:dd:907
1332c19:dd:c25:c25d:dd:dd:dd:908/1272c19:dd:c25:c25d:dd:dd:dd:909
1342c19:dd:c25:c25d:dd:dd:dd:90a/1272c19:dd:c25:c25d:dd:dd:dd:90b
1352c19:dd:c25:c25d:dd:dd:dd:90c/1272c19:dd:c25:c25d:dd:dd:dd:90d
1362c19:dd:c25:c25d:dd:dd:dd:90e/1272c19:dd:c25:c25d:dd:dd:dd:90f
1372c19:dd:c25:c25d:dd:dd:dd:910/1272c19:dd:c25:c25d:dd:dd:dd:911
1382c19:dd:c25:c25d:dd:dd:dd:912/1272c19:dd:c25:c25d:dd:dd:dd:913
1392c19:dd:c25:c25d:dd:dd:dd:914/1272c19:dd:c25:c25d:dd:dd:dd:915
1402c19:dd:c25:c25d:dd:dd:dd:916/1272c19:dd:c25:c25d:dd:dd:dd:917
1412c19:dd:c25:c25d:dd:dd:dd:918/1272c19:dd:c25:c25d:dd:dd:dd:919
1422c19:dd:c25:c25d:dd:dd:dd:91a/1272c19:dd:c25:c25d:dd:dd:dd:91b
1432c19:dd:c25:c25d:dd:dd:dd:91c/1272c19:dd:c25:c25d:dd:dd:dd:91d
1442c19:dd:c25:c25d:dd:dd:dd:91e/1272c19:dd:c25:c25d:dd:dd:dd:91f
1452c19:dd:c25:c25d:dd:dd:dd:920/1272c19:dd:c25:c25d:dd:dd:dd:921
1462c19:dd:c25:c25d:dd:dd:dd:922/1272c19:dd:c25:c25d:dd:dd:dd:923
1472c19:dd:c25:c25d:dd:dd:dd:924/1272c19:dd:c25:c25d:dd:dd:dd:925
1482c19:dd:c25:c25d:dd:dd:dd:926/1272c19:dd:c25:c25d:dd:dd:dd:927
1492c19:dd:c25:c25d:dd:dd:dd:928/1272c19:dd:c25:c25d:dd:dd:dd:929
1502c19:dd:c25:c25d:dd:dd:dd:92a/1272c19:dd:c25:c25d:dd:dd:dd:92b
1512c19:dd:c25:c25d:dd:dd:dd:92c/1272c19:dd:c25:c25d:dd:dd:dd:92d
1522c19:dd:c25:c25d:dd:dd:dd:92e/1272c19:dd:c25:c25d:dd:dd:dd:92f
1532c19:dd:c25:c25d:dd:dd:dd:930/1272c19:dd:c25:c25d:dd:dd:dd:931
1542c19:dd:c25:c25d:dd:dd:dd:932/1272c19:dd:c25:c25d:dd:dd:dd:933
1552c19:dd:c25:c25d:dd:dd:dd:934/1272c19:dd:c25:c25d:dd:dd:dd:935
1562c19:dd:c25:c25d:dd:dd:dd:936/1272c19:dd:c25:c25d:dd:dd:dd:937
1572c19:dd:c25:c25d:dd:dd:dd:938/1272c19:dd:c25:c25d:dd:dd:dd:939
1582c19:dd:c25:c25d:dd:dd:dd:93a/1272c19:dd:c25:c25d:dd:dd:dd:93b
1592c19:dd:c25:c25d:dd:dd:dd:93c/1272c19:dd:c25:c25d:dd:dd:dd:93d
1602c19:dd:c25:c25d:dd:dd:dd:93e/1272c19:dd:c25:c25d:dd:dd:dd:93f
1612c19:dd:c25:c25d:dd:dd:dd:940/1272c19:dd:c25:c25d:dd:dd:dd:941
1622c19:dd:c25:c25d:dd:dd:dd:942/1272c19:dd:c25:c25d:dd:dd:dd:943
1632c19:dd:c25:c25d:dd:dd:dd:944/1272c19:dd:c25:c25d:dd:dd:dd:945
1642c19:dd:c25:c25d:dd:dd:dd:946/1272c19:dd:c25:c25d:dd:dd:dd:947
1652c19:dd:c25:c25d:dd:dd:dd:948/1272c19:dd:c25:c25d:dd:dd:dd:949
1662c19:dd:c25:c25d:dd:dd:dd:94a/1272c19:dd:c25:c25d:dd:dd:dd:94b
1672c19:dd:c25:c25d:dd:dd:dd:94c/1272c19:dd:c25:c25d:dd:dd:dd:94d
1682c19:dd:c25:c25d:dd:dd:dd:94e/1272c19:dd:c25:c25d:dd:dd:dd:94f
1692c19:dd:c25:c25d:dd:dd:dd:950/1272c19:dd:c25:c25d:dd:dd:dd:951
1702c19:dd:c25:c25d:dd:dd:dd:952/1272c19:dd:c25:c25d:dd:dd:dd:953
1712c19:dd:c25:c25d:dd:dd:dd:954/1272c19:dd:c25:c25d:dd:dd:dd:955
1722c19:dd:c25:c25d:dd:dd:dd:956/1272c19:dd:c25:c25d:dd:dd:dd:957
1732c19:dd:c25:c25d:dd:dd:dd:958/1272c19:dd:c25:c25d:dd:dd:dd:959
1742c19:dd:c25:c25d:dd:dd:dd:95a/1272c19:dd:c25:c25d:dd:dd:dd:95b
1752c19:dd:c25:c25d:dd:dd:dd:95c/1272c19:dd:c25:c25d:dd:dd:dd:95d
1762c19:dd:c25:c25d:dd:dd:dd:95e/1272c19:dd:c25:c25d:dd:dd:dd:95f
1772c19:dd:c25:c25d:dd:dd:dd:960/1272c19:dd:c25:c25d:dd:dd:dd:961
1782c19:dd:c25:c25d:dd:dd:dd:962/1272c19:dd:c25:c25d:dd:dd:dd:963
1792c19:dd:c25:c25d:dd:dd:dd:964/1272c19:dd:c25:c25d:dd:dd:dd:965
1802c19:dd:c25:c25d:dd:dd:dd:966/1272c19:dd:c25:c25d:dd:dd:dd:967
1812c19:dd:c25:c25d:dd:dd:dd:968/1272c19:dd:c25:c25d:dd:dd:dd:969
1822c19:dd:c25:c25d:dd:dd:dd:96a/1272c19:dd:c25:c25d:dd:dd:dd:96b
1832c19:dd:c25:c25d:dd:dd:dd:96c/1272c19:dd:c25:c25d:dd:dd:dd:96d
1842c19:dd:c25:c25d:dd:dd:dd:96e/1272c19:dd:c25:c25d:dd:dd:dd:96f
1852c19:dd:c25:c25d:dd:dd:dd:970/1272c19:dd:c25:c25d:dd:dd:dd:971
1862c19:dd:c25:c25d:dd:dd:dd:972/1272c19:dd:c25:c25d:dd:dd:dd:973
1872c19:dd:c25:c25d:dd:dd:dd:974/1272c19:dd:c25:c25d:dd:dd:dd:975
1882c19:dd:c25:c25d:dd:dd:dd:976/1272c19:dd:c25:c25d:dd:dd:dd:977
1892c19:dd:c25:c25d:dd:dd:dd:978/1272c19:dd:c25:c25d:dd:dd:dd:979
1902c19:dd:c25:c25d:dd:dd:dd:97a/1272c19:dd:c25:c25d:dd:dd:dd:97b
1912c19:dd:c25:c25d:dd:dd:dd:97c/1272c19:dd:c25:c25d:dd:dd:dd:97d
1922c19:dd:c25:c25d:dd:dd:dd:97e/1272c19:dd:c25:c25d:dd:dd:dd:97f
1932c19:dd:c25:c25d:dd:dd:dd:980/1272c19:dd:c25:c25d:dd:dd:dd:981
1942c19:dd:c25:c25d:dd:dd:dd:982/1272c19:dd:c25:c25d:dd:dd:dd:983
1952c19:dd:c25:c25d:dd:dd:dd:984/1272c19:dd:c25:c25d:dd:dd:dd:985
1962c19:dd:c25:c25d:dd:dd:dd:986/1272c19:dd:c25:c25d:dd:dd:dd:987
1972c19:dd:c25:c25d:dd:dd:dd:988/1272c19:dd:c25:c25d:dd:dd:dd:989
1982c19:dd:c25:c25d:dd:dd:dd:98a/1272c19:dd:c25:c25d:dd:dd:dd:98b
1992c19:dd:c25:c25d:dd:dd:dd:98c/1272c19:dd:c25:c25d:dd:dd:dd:98d
2002c19:dd:c25:c25d:dd:dd:dd:98e/1272c19:dd:c25:c25d:dd:dd:dd:98f
2012c19:dd:c25:c25d:dd:dd:dd:990/1272c19:dd:c25:c25d:dd:dd:dd:991
2022c19:dd:c25:c25d:dd:dd:dd:992/1272c19:dd:c25:c25d:dd:dd:dd:993
2032c19:dd:c25:c25d:dd:dd:dd:994/1272c19:dd:c25:c25d:dd:dd:dd:995
2042c19:dd:c25:c25d:dd:dd:dd:996/1272c19:dd:c25:c25d:dd:dd:dd:997
2052c19:dd:c25:c25d:dd:dd:dd:998/1272c19:dd:c25:c25d:dd:dd:dd:999
2062c19:dd:c25:c25d:dd:dd:dd:99a/1272c19:dd:c25:c25d:dd:dd:dd:99b
2072c19:dd:c25:c25d:dd:dd:dd:99c/1272c19:dd:c25:c25d:dd:dd:dd:99d
2082c19:dd:c25:c25d:dd:dd:dd:99e/1272c19:dd:c25:c25d:dd:dd:dd:99f
2092c19:dd:c25:c25d:dd:dd:dd:9a0/1272c19:dd:c25:c25d:dd:dd:dd:9a1
2102c19:dd:c25:c25d:dd:dd:dd:9a2/1272c19:dd:c25:c25d:dd:dd:dd:9a3
2112c19:dd:c25:c25d:dd:dd:dd:9a4/1272c19:dd:c25:c25d:dd:dd:dd:9a5
2122c19:dd:c25:c25d:dd:dd:dd:9a6/1272c19:dd:c25:c25d:dd:dd:dd:9a7
2132c19:dd:c25:c25d:dd:dd:dd:9a8/1272c19:dd:c25:c25d:dd:dd:dd:9a9
2142c19:dd:c25:c25d:dd:dd:dd:9aa/1272c19:dd:c25:c25d:dd:dd:dd:9ab
2152c19:dd:c25:c25d:dd:dd:dd:9ac/1272c19:dd:c25:c25d:dd:dd:dd:9ad
2162c19:dd:c25:c25d:dd:dd:dd:9ae/1272c19:dd:c25:c25d:dd:dd:dd:9af
2172c19:dd:c25:c25d:dd:dd:dd:9b0/1272c19:dd:c25:c25d:dd:dd:dd:9b1
2182c19:dd:c25:c25d:dd:dd:dd:9b2/1272c19:dd:c25:c25d:dd:dd:dd:9b3
2192c19:dd:c25:c25d:dd:dd:dd:9b4/1272c19:dd:c25:c25d:dd:dd:dd:9b5
2202c19:dd:c25:c25d:dd:dd:dd:9b6/1272c19:dd:c25:c25d:dd:dd:dd:9b7
2212c19:dd:c25:c25d:dd:dd:dd:9b8/1272c19:dd:c25:c25d:dd:dd:dd:9b9
2222c19:dd:c25:c25d:dd:dd:dd:9ba/1272c19:dd:c25:c25d:dd:dd:dd:9bb
2232c19:dd:c25:c25d:dd:dd:dd:9bc/1272c19:dd:c25:c25d:dd:dd:dd:9bd
2242c19:dd:c25:c25d:dd:dd:dd:9be/1272c19:dd:c25:c25d:dd:dd:dd:9bf
2252c19:dd:c25:c25d:dd:dd:dd:9c0/1272c19:dd:c25:c25d:dd:dd:dd:9c1
2262c19:dd:c25:c25d:dd:dd:dd:9c2/1272c19:dd:c25:c25d:dd:dd:dd:9c3
2272c19:dd:c25:c25d:dd:dd:dd:9c4/1272c19:dd:c25:c25d:dd:dd:dd:9c5
2282c19:dd:c25:c25d:dd:dd:dd:9c6/1272c19:dd:c25:c25d:dd:dd:dd:9c7
2292c19:dd:c25:c25d:dd:dd:dd:9c8/1272c19:dd:c25:c25d:dd:dd:dd:9c9
2302c19:dd:c25:c25d:dd:dd:dd:9ca/1272c19:dd:c25:c25d:dd:dd:dd:9cb
2312c19:dd:c25:c25d:dd:dd:dd:9cc/1272c19:dd:c25:c25d:dd:dd:dd:9cd
2322c19:dd:c25:c25d:dd:dd:dd:9ce/1272c19:dd:c25:c25d:dd:dd:dd:9cf
2332c19:dd:c25:c25d:dd:dd:dd:9d0/1272c19:dd:c25:c25d:dd:dd:dd:9d1
2342c19:dd:c25:c25d:dd:dd:dd:9d2/1272c19:dd:c25:c25d:dd:dd:dd:9d3
2352c19:dd:c25:c25d:dd:dd:dd:9d4/1272c19:dd:c25:c25d:dd:dd:dd:9d5
2362c19:dd:c25:c25d:dd:dd:dd:9d6/1272c19:dd:c25:c25d:dd:dd:dd:9d7
2372c19:dd:c25:c25d:dd:dd:dd:9d8/1272c19:dd:c25:c25d:dd:dd:dd:9d9
2382c19:dd:c25:c25d:dd:dd:dd:9da/1272c19:dd:c25:c25d:dd:dd:dd:9db
2392c19:dd:c25:c25d:dd:dd:dd:9dc/1272c19:dd:c25:c25d:dd:dd:dd:9dd
2402c19:dd:c25:c25d:dd:dd:dd:9de/1272c19:dd:c25:c25d:dd:dd:dd:9df
2412c19:dd:c25:c25d:dd:dd:dd:9e0/1272c19:dd:c25:c25d:dd:dd:dd:9e1
2422c19:dd:c25:c25d:dd:dd:dd:9e2/1272c19:dd:c25:c25d:dd:dd:dd:9e3
2432c19:dd:c25:c25d:dd:dd:dd:9e4/1272c19:dd:c25:c25d:dd:dd:dd:9e5
2442c19:dd:c25:c25d:dd:dd:dd:9e6/1272c19:dd:c25:c25d:dd:dd:dd:9e7
2452c19:dd:c25:c25d:dd:dd:dd:9e8/1272c19:dd:c25:c25d:dd:dd:dd:9e9
2462c19:dd:c25:c25d:dd:dd:dd:9ea/1272c19:dd:c25:c25d:dd:dd:dd:9eb
2472c19:dd:c25:c25d:dd:dd:dd:9ec/1272c19:dd:c25:c25d:dd:dd:dd:9ed
2482c19:dd:c25:c25d:dd:dd:dd:9ee/1272c19:dd:c25:c25d:dd:dd:dd:9ef
2492c19:dd:c25:c25d:dd:dd:dd:9f0/1272c19:dd:c25:c25d:dd:dd:dd:9f1
2502c19:dd:c25:c25d:dd:dd:dd:9f2/1272c19:dd:c25:c25d:dd:dd:dd:9f3
2512c19:dd:c25:c25d:dd:dd:dd:9f4/1272c19:dd:c25:c25d:dd:dd:dd:9f5
2522c19:dd:c25:c25d:dd:dd:dd:9f6/1272c19:dd:c25:c25d:dd:dd:dd:9f7
2532c19:dd:c25:c25d:dd:dd:dd:9f8/1272c19:dd:c25:c25d:dd:dd:dd:9f9
2542c19:dd:c25:c25d:dd:dd:dd:9fa/1272c19:dd:c25:c25d:dd:dd:dd:9fb
2552c19:dd:c25:c25d:dd:dd:dd:9fc/1272c19:dd:c25:c25d:dd:dd:dd:9fd
2562c19:dd:c25:c25d:dd:dd:dd:9fe/1272c19:dd:c25:c25d:dd:dd:dd:9ff

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.