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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:9900/120
First address
2c19:dd:d9:dd:c25:c25:94de:9900
Last address
2c19:dd:d9:dd:c25:c25:94de:99ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:00d9:00dd:0c25:0c25:94de:9900
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
9.9.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:9900/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:d9:dd:c25:c25:94de:9900/1282c19:dd:d9:dd:c25:c25:94de:9900
22c19:dd:d9:dd:c25:c25:94de:9901/1282c19:dd:d9:dd:c25:c25:94de:9901
32c19:dd:d9:dd:c25:c25:94de:9902/1282c19:dd:d9:dd:c25:c25:94de:9902
42c19:dd:d9:dd:c25:c25:94de:9903/1282c19:dd:d9:dd:c25:c25:94de:9903
52c19:dd:d9:dd:c25:c25:94de:9904/1282c19:dd:d9:dd:c25:c25:94de:9904
62c19:dd:d9:dd:c25:c25:94de:9905/1282c19:dd:d9:dd:c25:c25:94de:9905
72c19:dd:d9:dd:c25:c25:94de:9906/1282c19:dd:d9:dd:c25:c25:94de:9906
82c19:dd:d9:dd:c25:c25:94de:9907/1282c19:dd:d9:dd:c25:c25:94de:9907
92c19:dd:d9:dd:c25:c25:94de:9908/1282c19:dd:d9:dd:c25:c25:94de:9908
102c19:dd:d9:dd:c25:c25:94de:9909/1282c19:dd:d9:dd:c25:c25:94de:9909
112c19:dd:d9:dd:c25:c25:94de:990a/1282c19:dd:d9:dd:c25:c25:94de:990a
122c19:dd:d9:dd:c25:c25:94de:990b/1282c19:dd:d9:dd:c25:c25:94de:990b
132c19:dd:d9:dd:c25:c25:94de:990c/1282c19:dd:d9:dd:c25:c25:94de:990c
142c19:dd:d9:dd:c25:c25:94de:990d/1282c19:dd:d9:dd:c25:c25:94de:990d
152c19:dd:d9:dd:c25:c25:94de:990e/1282c19:dd:d9:dd:c25:c25:94de:990e
162c19:dd:d9:dd:c25:c25:94de:990f/1282c19:dd:d9:dd:c25:c25:94de:990f
172c19:dd:d9:dd:c25:c25:94de:9910/1282c19:dd:d9:dd:c25:c25:94de:9910
182c19:dd:d9:dd:c25:c25:94de:9911/1282c19:dd:d9:dd:c25:c25:94de:9911
192c19:dd:d9:dd:c25:c25:94de:9912/1282c19:dd:d9:dd:c25:c25:94de:9912
202c19:dd:d9:dd:c25:c25:94de:9913/1282c19:dd:d9:dd:c25:c25:94de:9913
212c19:dd:d9:dd:c25:c25:94de:9914/1282c19:dd:d9:dd:c25:c25:94de:9914
222c19:dd:d9:dd:c25:c25:94de:9915/1282c19:dd:d9:dd:c25:c25:94de:9915
232c19:dd:d9:dd:c25:c25:94de:9916/1282c19:dd:d9:dd:c25:c25:94de:9916
242c19:dd:d9:dd:c25:c25:94de:9917/1282c19:dd:d9:dd:c25:c25:94de:9917
252c19:dd:d9:dd:c25:c25:94de:9918/1282c19:dd:d9:dd:c25:c25:94de:9918
262c19:dd:d9:dd:c25:c25:94de:9919/1282c19:dd:d9:dd:c25:c25:94de:9919
272c19:dd:d9:dd:c25:c25:94de:991a/1282c19:dd:d9:dd:c25:c25:94de:991a
282c19:dd:d9:dd:c25:c25:94de:991b/1282c19:dd:d9:dd:c25:c25:94de:991b
292c19:dd:d9:dd:c25:c25:94de:991c/1282c19:dd:d9:dd:c25:c25:94de:991c
302c19:dd:d9:dd:c25:c25:94de:991d/1282c19:dd:d9:dd:c25:c25:94de:991d
312c19:dd:d9:dd:c25:c25:94de:991e/1282c19:dd:d9:dd:c25:c25:94de:991e
322c19:dd:d9:dd:c25:c25:94de:991f/1282c19:dd:d9:dd:c25:c25:94de:991f
332c19:dd:d9:dd:c25:c25:94de:9920/1282c19:dd:d9:dd:c25:c25:94de:9920
342c19:dd:d9:dd:c25:c25:94de:9921/1282c19:dd:d9:dd:c25:c25:94de:9921
352c19:dd:d9:dd:c25:c25:94de:9922/1282c19:dd:d9:dd:c25:c25:94de:9922
362c19:dd:d9:dd:c25:c25:94de:9923/1282c19:dd:d9:dd:c25:c25:94de:9923
372c19:dd:d9:dd:c25:c25:94de:9924/1282c19:dd:d9:dd:c25:c25:94de:9924
382c19:dd:d9:dd:c25:c25:94de:9925/1282c19:dd:d9:dd:c25:c25:94de:9925
392c19:dd:d9:dd:c25:c25:94de:9926/1282c19:dd:d9:dd:c25:c25:94de:9926
402c19:dd:d9:dd:c25:c25:94de:9927/1282c19:dd:d9:dd:c25:c25:94de:9927
412c19:dd:d9:dd:c25:c25:94de:9928/1282c19:dd:d9:dd:c25:c25:94de:9928
422c19:dd:d9:dd:c25:c25:94de:9929/1282c19:dd:d9:dd:c25:c25:94de:9929
432c19:dd:d9:dd:c25:c25:94de:992a/1282c19:dd:d9:dd:c25:c25:94de:992a
442c19:dd:d9:dd:c25:c25:94de:992b/1282c19:dd:d9:dd:c25:c25:94de:992b
452c19:dd:d9:dd:c25:c25:94de:992c/1282c19:dd:d9:dd:c25:c25:94de:992c
462c19:dd:d9:dd:c25:c25:94de:992d/1282c19:dd:d9:dd:c25:c25:94de:992d
472c19:dd:d9:dd:c25:c25:94de:992e/1282c19:dd:d9:dd:c25:c25:94de:992e
482c19:dd:d9:dd:c25:c25:94de:992f/1282c19:dd:d9:dd:c25:c25:94de:992f
492c19:dd:d9:dd:c25:c25:94de:9930/1282c19:dd:d9:dd:c25:c25:94de:9930
502c19:dd:d9:dd:c25:c25:94de:9931/1282c19:dd:d9:dd:c25:c25:94de:9931
512c19:dd:d9:dd:c25:c25:94de:9932/1282c19:dd:d9:dd:c25:c25:94de:9932
522c19:dd:d9:dd:c25:c25:94de:9933/1282c19:dd:d9:dd:c25:c25:94de:9933
532c19:dd:d9:dd:c25:c25:94de:9934/1282c19:dd:d9:dd:c25:c25:94de:9934
542c19:dd:d9:dd:c25:c25:94de:9935/1282c19:dd:d9:dd:c25:c25:94de:9935
552c19:dd:d9:dd:c25:c25:94de:9936/1282c19:dd:d9:dd:c25:c25:94de:9936
562c19:dd:d9:dd:c25:c25:94de:9937/1282c19:dd:d9:dd:c25:c25:94de:9937
572c19:dd:d9:dd:c25:c25:94de:9938/1282c19:dd:d9:dd:c25:c25:94de:9938
582c19:dd:d9:dd:c25:c25:94de:9939/1282c19:dd:d9:dd:c25:c25:94de:9939
592c19:dd:d9:dd:c25:c25:94de:993a/1282c19:dd:d9:dd:c25:c25:94de:993a
602c19:dd:d9:dd:c25:c25:94de:993b/1282c19:dd:d9:dd:c25:c25:94de:993b
612c19:dd:d9:dd:c25:c25:94de:993c/1282c19:dd:d9:dd:c25:c25:94de:993c
622c19:dd:d9:dd:c25:c25:94de:993d/1282c19:dd:d9:dd:c25:c25:94de:993d
632c19:dd:d9:dd:c25:c25:94de:993e/1282c19:dd:d9:dd:c25:c25:94de:993e
642c19:dd:d9:dd:c25:c25:94de:993f/1282c19:dd:d9:dd:c25:c25:94de:993f
652c19:dd:d9:dd:c25:c25:94de:9940/1282c19:dd:d9:dd:c25:c25:94de:9940
662c19:dd:d9:dd:c25:c25:94de:9941/1282c19:dd:d9:dd:c25:c25:94de:9941
672c19:dd:d9:dd:c25:c25:94de:9942/1282c19:dd:d9:dd:c25:c25:94de:9942
682c19:dd:d9:dd:c25:c25:94de:9943/1282c19:dd:d9:dd:c25:c25:94de:9943
692c19:dd:d9:dd:c25:c25:94de:9944/1282c19:dd:d9:dd:c25:c25:94de:9944
702c19:dd:d9:dd:c25:c25:94de:9945/1282c19:dd:d9:dd:c25:c25:94de:9945
712c19:dd:d9:dd:c25:c25:94de:9946/1282c19:dd:d9:dd:c25:c25:94de:9946
722c19:dd:d9:dd:c25:c25:94de:9947/1282c19:dd:d9:dd:c25:c25:94de:9947
732c19:dd:d9:dd:c25:c25:94de:9948/1282c19:dd:d9:dd:c25:c25:94de:9948
742c19:dd:d9:dd:c25:c25:94de:9949/1282c19:dd:d9:dd:c25:c25:94de:9949
752c19:dd:d9:dd:c25:c25:94de:994a/1282c19:dd:d9:dd:c25:c25:94de:994a
762c19:dd:d9:dd:c25:c25:94de:994b/1282c19:dd:d9:dd:c25:c25:94de:994b
772c19:dd:d9:dd:c25:c25:94de:994c/1282c19:dd:d9:dd:c25:c25:94de:994c
782c19:dd:d9:dd:c25:c25:94de:994d/1282c19:dd:d9:dd:c25:c25:94de:994d
792c19:dd:d9:dd:c25:c25:94de:994e/1282c19:dd:d9:dd:c25:c25:94de:994e
802c19:dd:d9:dd:c25:c25:94de:994f/1282c19:dd:d9:dd:c25:c25:94de:994f
812c19:dd:d9:dd:c25:c25:94de:9950/1282c19:dd:d9:dd:c25:c25:94de:9950
822c19:dd:d9:dd:c25:c25:94de:9951/1282c19:dd:d9:dd:c25:c25:94de:9951
832c19:dd:d9:dd:c25:c25:94de:9952/1282c19:dd:d9:dd:c25:c25:94de:9952
842c19:dd:d9:dd:c25:c25:94de:9953/1282c19:dd:d9:dd:c25:c25:94de:9953
852c19:dd:d9:dd:c25:c25:94de:9954/1282c19:dd:d9:dd:c25:c25:94de:9954
862c19:dd:d9:dd:c25:c25:94de:9955/1282c19:dd:d9:dd:c25:c25:94de:9955
872c19:dd:d9:dd:c25:c25:94de:9956/1282c19:dd:d9:dd:c25:c25:94de:9956
882c19:dd:d9:dd:c25:c25:94de:9957/1282c19:dd:d9:dd:c25:c25:94de:9957
892c19:dd:d9:dd:c25:c25:94de:9958/1282c19:dd:d9:dd:c25:c25:94de:9958
902c19:dd:d9:dd:c25:c25:94de:9959/1282c19:dd:d9:dd:c25:c25:94de:9959
912c19:dd:d9:dd:c25:c25:94de:995a/1282c19:dd:d9:dd:c25:c25:94de:995a
922c19:dd:d9:dd:c25:c25:94de:995b/1282c19:dd:d9:dd:c25:c25:94de:995b
932c19:dd:d9:dd:c25:c25:94de:995c/1282c19:dd:d9:dd:c25:c25:94de:995c
942c19:dd:d9:dd:c25:c25:94de:995d/1282c19:dd:d9:dd:c25:c25:94de:995d
952c19:dd:d9:dd:c25:c25:94de:995e/1282c19:dd:d9:dd:c25:c25:94de:995e
962c19:dd:d9:dd:c25:c25:94de:995f/1282c19:dd:d9:dd:c25:c25:94de:995f
972c19:dd:d9:dd:c25:c25:94de:9960/1282c19:dd:d9:dd:c25:c25:94de:9960
982c19:dd:d9:dd:c25:c25:94de:9961/1282c19:dd:d9:dd:c25:c25:94de:9961
992c19:dd:d9:dd:c25:c25:94de:9962/1282c19:dd:d9:dd:c25:c25:94de:9962
1002c19:dd:d9:dd:c25:c25:94de:9963/1282c19:dd:d9:dd:c25:c25:94de:9963
1012c19:dd:d9:dd:c25:c25:94de:9964/1282c19:dd:d9:dd:c25:c25:94de:9964
1022c19:dd:d9:dd:c25:c25:94de:9965/1282c19:dd:d9:dd:c25:c25:94de:9965
1032c19:dd:d9:dd:c25:c25:94de:9966/1282c19:dd:d9:dd:c25:c25:94de:9966
1042c19:dd:d9:dd:c25:c25:94de:9967/1282c19:dd:d9:dd:c25:c25:94de:9967
1052c19:dd:d9:dd:c25:c25:94de:9968/1282c19:dd:d9:dd:c25:c25:94de:9968
1062c19:dd:d9:dd:c25:c25:94de:9969/1282c19:dd:d9:dd:c25:c25:94de:9969
1072c19:dd:d9:dd:c25:c25:94de:996a/1282c19:dd:d9:dd:c25:c25:94de:996a
1082c19:dd:d9:dd:c25:c25:94de:996b/1282c19:dd:d9:dd:c25:c25:94de:996b
1092c19:dd:d9:dd:c25:c25:94de:996c/1282c19:dd:d9:dd:c25:c25:94de:996c
1102c19:dd:d9:dd:c25:c25:94de:996d/1282c19:dd:d9:dd:c25:c25:94de:996d
1112c19:dd:d9:dd:c25:c25:94de:996e/1282c19:dd:d9:dd:c25:c25:94de:996e
1122c19:dd:d9:dd:c25:c25:94de:996f/1282c19:dd:d9:dd:c25:c25:94de:996f
1132c19:dd:d9:dd:c25:c25:94de:9970/1282c19:dd:d9:dd:c25:c25:94de:9970
1142c19:dd:d9:dd:c25:c25:94de:9971/1282c19:dd:d9:dd:c25:c25:94de:9971
1152c19:dd:d9:dd:c25:c25:94de:9972/1282c19:dd:d9:dd:c25:c25:94de:9972
1162c19:dd:d9:dd:c25:c25:94de:9973/1282c19:dd:d9:dd:c25:c25:94de:9973
1172c19:dd:d9:dd:c25:c25:94de:9974/1282c19:dd:d9:dd:c25:c25:94de:9974
1182c19:dd:d9:dd:c25:c25:94de:9975/1282c19:dd:d9:dd:c25:c25:94de:9975
1192c19:dd:d9:dd:c25:c25:94de:9976/1282c19:dd:d9:dd:c25:c25:94de:9976
1202c19:dd:d9:dd:c25:c25:94de:9977/1282c19:dd:d9:dd:c25:c25:94de:9977
1212c19:dd:d9:dd:c25:c25:94de:9978/1282c19:dd:d9:dd:c25:c25:94de:9978
1222c19:dd:d9:dd:c25:c25:94de:9979/1282c19:dd:d9:dd:c25:c25:94de:9979
1232c19:dd:d9:dd:c25:c25:94de:997a/1282c19:dd:d9:dd:c25:c25:94de:997a
1242c19:dd:d9:dd:c25:c25:94de:997b/1282c19:dd:d9:dd:c25:c25:94de:997b
1252c19:dd:d9:dd:c25:c25:94de:997c/1282c19:dd:d9:dd:c25:c25:94de:997c
1262c19:dd:d9:dd:c25:c25:94de:997d/1282c19:dd:d9:dd:c25:c25:94de:997d
1272c19:dd:d9:dd:c25:c25:94de:997e/1282c19:dd:d9:dd:c25:c25:94de:997e
1282c19:dd:d9:dd:c25:c25:94de:997f/1282c19:dd:d9:dd:c25:c25:94de:997f
1292c19:dd:d9:dd:c25:c25:94de:9980/1282c19:dd:d9:dd:c25:c25:94de:9980
1302c19:dd:d9:dd:c25:c25:94de:9981/1282c19:dd:d9:dd:c25:c25:94de:9981
1312c19:dd:d9:dd:c25:c25:94de:9982/1282c19:dd:d9:dd:c25:c25:94de:9982
1322c19:dd:d9:dd:c25:c25:94de:9983/1282c19:dd:d9:dd:c25:c25:94de:9983
1332c19:dd:d9:dd:c25:c25:94de:9984/1282c19:dd:d9:dd:c25:c25:94de:9984
1342c19:dd:d9:dd:c25:c25:94de:9985/1282c19:dd:d9:dd:c25:c25:94de:9985
1352c19:dd:d9:dd:c25:c25:94de:9986/1282c19:dd:d9:dd:c25:c25:94de:9986
1362c19:dd:d9:dd:c25:c25:94de:9987/1282c19:dd:d9:dd:c25:c25:94de:9987
1372c19:dd:d9:dd:c25:c25:94de:9988/1282c19:dd:d9:dd:c25:c25:94de:9988
1382c19:dd:d9:dd:c25:c25:94de:9989/1282c19:dd:d9:dd:c25:c25:94de:9989
1392c19:dd:d9:dd:c25:c25:94de:998a/1282c19:dd:d9:dd:c25:c25:94de:998a
1402c19:dd:d9:dd:c25:c25:94de:998b/1282c19:dd:d9:dd:c25:c25:94de:998b
1412c19:dd:d9:dd:c25:c25:94de:998c/1282c19:dd:d9:dd:c25:c25:94de:998c
1422c19:dd:d9:dd:c25:c25:94de:998d/1282c19:dd:d9:dd:c25:c25:94de:998d
1432c19:dd:d9:dd:c25:c25:94de:998e/1282c19:dd:d9:dd:c25:c25:94de:998e
1442c19:dd:d9:dd:c25:c25:94de:998f/1282c19:dd:d9:dd:c25:c25:94de:998f
1452c19:dd:d9:dd:c25:c25:94de:9990/1282c19:dd:d9:dd:c25:c25:94de:9990
1462c19:dd:d9:dd:c25:c25:94de:9991/1282c19:dd:d9:dd:c25:c25:94de:9991
1472c19:dd:d9:dd:c25:c25:94de:9992/1282c19:dd:d9:dd:c25:c25:94de:9992
1482c19:dd:d9:dd:c25:c25:94de:9993/1282c19:dd:d9:dd:c25:c25:94de:9993
1492c19:dd:d9:dd:c25:c25:94de:9994/1282c19:dd:d9:dd:c25:c25:94de:9994
1502c19:dd:d9:dd:c25:c25:94de:9995/1282c19:dd:d9:dd:c25:c25:94de:9995
1512c19:dd:d9:dd:c25:c25:94de:9996/1282c19:dd:d9:dd:c25:c25:94de:9996
1522c19:dd:d9:dd:c25:c25:94de:9997/1282c19:dd:d9:dd:c25:c25:94de:9997
1532c19:dd:d9:dd:c25:c25:94de:9998/1282c19:dd:d9:dd:c25:c25:94de:9998
1542c19:dd:d9:dd:c25:c25:94de:9999/1282c19:dd:d9:dd:c25:c25:94de:9999
1552c19:dd:d9:dd:c25:c25:94de:999a/1282c19:dd:d9:dd:c25:c25:94de:999a
1562c19:dd:d9:dd:c25:c25:94de:999b/1282c19:dd:d9:dd:c25:c25:94de:999b
1572c19:dd:d9:dd:c25:c25:94de:999c/1282c19:dd:d9:dd:c25:c25:94de:999c
1582c19:dd:d9:dd:c25:c25:94de:999d/1282c19:dd:d9:dd:c25:c25:94de:999d
1592c19:dd:d9:dd:c25:c25:94de:999e/1282c19:dd:d9:dd:c25:c25:94de:999e
1602c19:dd:d9:dd:c25:c25:94de:999f/1282c19:dd:d9:dd:c25:c25:94de:999f
1612c19:dd:d9:dd:c25:c25:94de:99a0/1282c19:dd:d9:dd:c25:c25:94de:99a0
1622c19:dd:d9:dd:c25:c25:94de:99a1/1282c19:dd:d9:dd:c25:c25:94de:99a1
1632c19:dd:d9:dd:c25:c25:94de:99a2/1282c19:dd:d9:dd:c25:c25:94de:99a2
1642c19:dd:d9:dd:c25:c25:94de:99a3/1282c19:dd:d9:dd:c25:c25:94de:99a3
1652c19:dd:d9:dd:c25:c25:94de:99a4/1282c19:dd:d9:dd:c25:c25:94de:99a4
1662c19:dd:d9:dd:c25:c25:94de:99a5/1282c19:dd:d9:dd:c25:c25:94de:99a5
1672c19:dd:d9:dd:c25:c25:94de:99a6/1282c19:dd:d9:dd:c25:c25:94de:99a6
1682c19:dd:d9:dd:c25:c25:94de:99a7/1282c19:dd:d9:dd:c25:c25:94de:99a7
1692c19:dd:d9:dd:c25:c25:94de:99a8/1282c19:dd:d9:dd:c25:c25:94de:99a8
1702c19:dd:d9:dd:c25:c25:94de:99a9/1282c19:dd:d9:dd:c25:c25:94de:99a9
1712c19:dd:d9:dd:c25:c25:94de:99aa/1282c19:dd:d9:dd:c25:c25:94de:99aa
1722c19:dd:d9:dd:c25:c25:94de:99ab/1282c19:dd:d9:dd:c25:c25:94de:99ab
1732c19:dd:d9:dd:c25:c25:94de:99ac/1282c19:dd:d9:dd:c25:c25:94de:99ac
1742c19:dd:d9:dd:c25:c25:94de:99ad/1282c19:dd:d9:dd:c25:c25:94de:99ad
1752c19:dd:d9:dd:c25:c25:94de:99ae/1282c19:dd:d9:dd:c25:c25:94de:99ae
1762c19:dd:d9:dd:c25:c25:94de:99af/1282c19:dd:d9:dd:c25:c25:94de:99af
1772c19:dd:d9:dd:c25:c25:94de:99b0/1282c19:dd:d9:dd:c25:c25:94de:99b0
1782c19:dd:d9:dd:c25:c25:94de:99b1/1282c19:dd:d9:dd:c25:c25:94de:99b1
1792c19:dd:d9:dd:c25:c25:94de:99b2/1282c19:dd:d9:dd:c25:c25:94de:99b2
1802c19:dd:d9:dd:c25:c25:94de:99b3/1282c19:dd:d9:dd:c25:c25:94de:99b3
1812c19:dd:d9:dd:c25:c25:94de:99b4/1282c19:dd:d9:dd:c25:c25:94de:99b4
1822c19:dd:d9:dd:c25:c25:94de:99b5/1282c19:dd:d9:dd:c25:c25:94de:99b5
1832c19:dd:d9:dd:c25:c25:94de:99b6/1282c19:dd:d9:dd:c25:c25:94de:99b6
1842c19:dd:d9:dd:c25:c25:94de:99b7/1282c19:dd:d9:dd:c25:c25:94de:99b7
1852c19:dd:d9:dd:c25:c25:94de:99b8/1282c19:dd:d9:dd:c25:c25:94de:99b8
1862c19:dd:d9:dd:c25:c25:94de:99b9/1282c19:dd:d9:dd:c25:c25:94de:99b9
1872c19:dd:d9:dd:c25:c25:94de:99ba/1282c19:dd:d9:dd:c25:c25:94de:99ba
1882c19:dd:d9:dd:c25:c25:94de:99bb/1282c19:dd:d9:dd:c25:c25:94de:99bb
1892c19:dd:d9:dd:c25:c25:94de:99bc/1282c19:dd:d9:dd:c25:c25:94de:99bc
1902c19:dd:d9:dd:c25:c25:94de:99bd/1282c19:dd:d9:dd:c25:c25:94de:99bd
1912c19:dd:d9:dd:c25:c25:94de:99be/1282c19:dd:d9:dd:c25:c25:94de:99be
1922c19:dd:d9:dd:c25:c25:94de:99bf/1282c19:dd:d9:dd:c25:c25:94de:99bf
1932c19:dd:d9:dd:c25:c25:94de:99c0/1282c19:dd:d9:dd:c25:c25:94de:99c0
1942c19:dd:d9:dd:c25:c25:94de:99c1/1282c19:dd:d9:dd:c25:c25:94de:99c1
1952c19:dd:d9:dd:c25:c25:94de:99c2/1282c19:dd:d9:dd:c25:c25:94de:99c2
1962c19:dd:d9:dd:c25:c25:94de:99c3/1282c19:dd:d9:dd:c25:c25:94de:99c3
1972c19:dd:d9:dd:c25:c25:94de:99c4/1282c19:dd:d9:dd:c25:c25:94de:99c4
1982c19:dd:d9:dd:c25:c25:94de:99c5/1282c19:dd:d9:dd:c25:c25:94de:99c5
1992c19:dd:d9:dd:c25:c25:94de:99c6/1282c19:dd:d9:dd:c25:c25:94de:99c6
2002c19:dd:d9:dd:c25:c25:94de:99c7/1282c19:dd:d9:dd:c25:c25:94de:99c7
2012c19:dd:d9:dd:c25:c25:94de:99c8/1282c19:dd:d9:dd:c25:c25:94de:99c8
2022c19:dd:d9:dd:c25:c25:94de:99c9/1282c19:dd:d9:dd:c25:c25:94de:99c9
2032c19:dd:d9:dd:c25:c25:94de:99ca/1282c19:dd:d9:dd:c25:c25:94de:99ca
2042c19:dd:d9:dd:c25:c25:94de:99cb/1282c19:dd:d9:dd:c25:c25:94de:99cb
2052c19:dd:d9:dd:c25:c25:94de:99cc/1282c19:dd:d9:dd:c25:c25:94de:99cc
2062c19:dd:d9:dd:c25:c25:94de:99cd/1282c19:dd:d9:dd:c25:c25:94de:99cd
2072c19:dd:d9:dd:c25:c25:94de:99ce/1282c19:dd:d9:dd:c25:c25:94de:99ce
2082c19:dd:d9:dd:c25:c25:94de:99cf/1282c19:dd:d9:dd:c25:c25:94de:99cf
2092c19:dd:d9:dd:c25:c25:94de:99d0/1282c19:dd:d9:dd:c25:c25:94de:99d0
2102c19:dd:d9:dd:c25:c25:94de:99d1/1282c19:dd:d9:dd:c25:c25:94de:99d1
2112c19:dd:d9:dd:c25:c25:94de:99d2/1282c19:dd:d9:dd:c25:c25:94de:99d2
2122c19:dd:d9:dd:c25:c25:94de:99d3/1282c19:dd:d9:dd:c25:c25:94de:99d3
2132c19:dd:d9:dd:c25:c25:94de:99d4/1282c19:dd:d9:dd:c25:c25:94de:99d4
2142c19:dd:d9:dd:c25:c25:94de:99d5/1282c19:dd:d9:dd:c25:c25:94de:99d5
2152c19:dd:d9:dd:c25:c25:94de:99d6/1282c19:dd:d9:dd:c25:c25:94de:99d6
2162c19:dd:d9:dd:c25:c25:94de:99d7/1282c19:dd:d9:dd:c25:c25:94de:99d7
2172c19:dd:d9:dd:c25:c25:94de:99d8/1282c19:dd:d9:dd:c25:c25:94de:99d8
2182c19:dd:d9:dd:c25:c25:94de:99d9/1282c19:dd:d9:dd:c25:c25:94de:99d9
2192c19:dd:d9:dd:c25:c25:94de:99da/1282c19:dd:d9:dd:c25:c25:94de:99da
2202c19:dd:d9:dd:c25:c25:94de:99db/1282c19:dd:d9:dd:c25:c25:94de:99db
2212c19:dd:d9:dd:c25:c25:94de:99dc/1282c19:dd:d9:dd:c25:c25:94de:99dc
2222c19:dd:d9:dd:c25:c25:94de:99dd/1282c19:dd:d9:dd:c25:c25:94de:99dd
2232c19:dd:d9:dd:c25:c25:94de:99de/1282c19:dd:d9:dd:c25:c25:94de:99de
2242c19:dd:d9:dd:c25:c25:94de:99df/1282c19:dd:d9:dd:c25:c25:94de:99df
2252c19:dd:d9:dd:c25:c25:94de:99e0/1282c19:dd:d9:dd:c25:c25:94de:99e0
2262c19:dd:d9:dd:c25:c25:94de:99e1/1282c19:dd:d9:dd:c25:c25:94de:99e1
2272c19:dd:d9:dd:c25:c25:94de:99e2/1282c19:dd:d9:dd:c25:c25:94de:99e2
2282c19:dd:d9:dd:c25:c25:94de:99e3/1282c19:dd:d9:dd:c25:c25:94de:99e3
2292c19:dd:d9:dd:c25:c25:94de:99e4/1282c19:dd:d9:dd:c25:c25:94de:99e4
2302c19:dd:d9:dd:c25:c25:94de:99e5/1282c19:dd:d9:dd:c25:c25:94de:99e5
2312c19:dd:d9:dd:c25:c25:94de:99e6/1282c19:dd:d9:dd:c25:c25:94de:99e6
2322c19:dd:d9:dd:c25:c25:94de:99e7/1282c19:dd:d9:dd:c25:c25:94de:99e7
2332c19:dd:d9:dd:c25:c25:94de:99e8/1282c19:dd:d9:dd:c25:c25:94de:99e8
2342c19:dd:d9:dd:c25:c25:94de:99e9/1282c19:dd:d9:dd:c25:c25:94de:99e9
2352c19:dd:d9:dd:c25:c25:94de:99ea/1282c19:dd:d9:dd:c25:c25:94de:99ea
2362c19:dd:d9:dd:c25:c25:94de:99eb/1282c19:dd:d9:dd:c25:c25:94de:99eb
2372c19:dd:d9:dd:c25:c25:94de:99ec/1282c19:dd:d9:dd:c25:c25:94de:99ec
2382c19:dd:d9:dd:c25:c25:94de:99ed/1282c19:dd:d9:dd:c25:c25:94de:99ed
2392c19:dd:d9:dd:c25:c25:94de:99ee/1282c19:dd:d9:dd:c25:c25:94de:99ee
2402c19:dd:d9:dd:c25:c25:94de:99ef/1282c19:dd:d9:dd:c25:c25:94de:99ef
2412c19:dd:d9:dd:c25:c25:94de:99f0/1282c19:dd:d9:dd:c25:c25:94de:99f0
2422c19:dd:d9:dd:c25:c25:94de:99f1/1282c19:dd:d9:dd:c25:c25:94de:99f1
2432c19:dd:d9:dd:c25:c25:94de:99f2/1282c19:dd:d9:dd:c25:c25:94de:99f2
2442c19:dd:d9:dd:c25:c25:94de:99f3/1282c19:dd:d9:dd:c25:c25:94de:99f3
2452c19:dd:d9:dd:c25:c25:94de:99f4/1282c19:dd:d9:dd:c25:c25:94de:99f4
2462c19:dd:d9:dd:c25:c25:94de:99f5/1282c19:dd:d9:dd:c25:c25:94de:99f5
2472c19:dd:d9:dd:c25:c25:94de:99f6/1282c19:dd:d9:dd:c25:c25:94de:99f6
2482c19:dd:d9:dd:c25:c25:94de:99f7/1282c19:dd:d9:dd:c25:c25:94de:99f7
2492c19:dd:d9:dd:c25:c25:94de:99f8/1282c19:dd:d9:dd:c25:c25:94de:99f8
2502c19:dd:d9:dd:c25:c25:94de:99f9/1282c19:dd:d9:dd:c25:c25:94de:99f9
2512c19:dd:d9:dd:c25:c25:94de:99fa/1282c19:dd:d9:dd:c25:c25:94de:99fa
2522c19:dd:d9:dd:c25:c25:94de:99fb/1282c19:dd:d9:dd:c25:c25:94de:99fb
2532c19:dd:d9:dd:c25:c25:94de:99fc/1282c19:dd:d9:dd:c25:c25:94de:99fc
2542c19:dd:d9:dd:c25:c25:94de:99fd/1282c19:dd:d9:dd:c25:c25:94de:99fd
2552c19:dd:d9:dd:c25:c25:94de:99fe/1282c19:dd:d9:dd:c25:c25:94de:99fe
2562c19:dd:d9:dd:c25:c25:94de:99ff/1282c19:dd:d9:dd:c25:c25:94de:99ff

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.