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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:c25a:d00a:1900/120
First address
2c19:dd:d9:dd:c25:c25a:d00a:1900
Last address
2c19:dd:d9:dd:c25:c25a:d00a:19ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:00d9:00dd:0c25:c25a:d00a:1900
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
9.1.a.0.0.d.a.5.2.c.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:c25a:d00a:1900/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:d9:dd:c25:c25a:d00a:1900/1282c19:dd:d9:dd:c25:c25a:d00a:1900
22c19:dd:d9:dd:c25:c25a:d00a:1901/1282c19:dd:d9:dd:c25:c25a:d00a:1901
32c19:dd:d9:dd:c25:c25a:d00a:1902/1282c19:dd:d9:dd:c25:c25a:d00a:1902
42c19:dd:d9:dd:c25:c25a:d00a:1903/1282c19:dd:d9:dd:c25:c25a:d00a:1903
52c19:dd:d9:dd:c25:c25a:d00a:1904/1282c19:dd:d9:dd:c25:c25a:d00a:1904
62c19:dd:d9:dd:c25:c25a:d00a:1905/1282c19:dd:d9:dd:c25:c25a:d00a:1905
72c19:dd:d9:dd:c25:c25a:d00a:1906/1282c19:dd:d9:dd:c25:c25a:d00a:1906
82c19:dd:d9:dd:c25:c25a:d00a:1907/1282c19:dd:d9:dd:c25:c25a:d00a:1907
92c19:dd:d9:dd:c25:c25a:d00a:1908/1282c19:dd:d9:dd:c25:c25a:d00a:1908
102c19:dd:d9:dd:c25:c25a:d00a:1909/1282c19:dd:d9:dd:c25:c25a:d00a:1909
112c19:dd:d9:dd:c25:c25a:d00a:190a/1282c19:dd:d9:dd:c25:c25a:d00a:190a
122c19:dd:d9:dd:c25:c25a:d00a:190b/1282c19:dd:d9:dd:c25:c25a:d00a:190b
132c19:dd:d9:dd:c25:c25a:d00a:190c/1282c19:dd:d9:dd:c25:c25a:d00a:190c
142c19:dd:d9:dd:c25:c25a:d00a:190d/1282c19:dd:d9:dd:c25:c25a:d00a:190d
152c19:dd:d9:dd:c25:c25a:d00a:190e/1282c19:dd:d9:dd:c25:c25a:d00a:190e
162c19:dd:d9:dd:c25:c25a:d00a:190f/1282c19:dd:d9:dd:c25:c25a:d00a:190f
172c19:dd:d9:dd:c25:c25a:d00a:1910/1282c19:dd:d9:dd:c25:c25a:d00a:1910
182c19:dd:d9:dd:c25:c25a:d00a:1911/1282c19:dd:d9:dd:c25:c25a:d00a:1911
192c19:dd:d9:dd:c25:c25a:d00a:1912/1282c19:dd:d9:dd:c25:c25a:d00a:1912
202c19:dd:d9:dd:c25:c25a:d00a:1913/1282c19:dd:d9:dd:c25:c25a:d00a:1913
212c19:dd:d9:dd:c25:c25a:d00a:1914/1282c19:dd:d9:dd:c25:c25a:d00a:1914
222c19:dd:d9:dd:c25:c25a:d00a:1915/1282c19:dd:d9:dd:c25:c25a:d00a:1915
232c19:dd:d9:dd:c25:c25a:d00a:1916/1282c19:dd:d9:dd:c25:c25a:d00a:1916
242c19:dd:d9:dd:c25:c25a:d00a:1917/1282c19:dd:d9:dd:c25:c25a:d00a:1917
252c19:dd:d9:dd:c25:c25a:d00a:1918/1282c19:dd:d9:dd:c25:c25a:d00a:1918
262c19:dd:d9:dd:c25:c25a:d00a:1919/1282c19:dd:d9:dd:c25:c25a:d00a:1919
272c19:dd:d9:dd:c25:c25a:d00a:191a/1282c19:dd:d9:dd:c25:c25a:d00a:191a
282c19:dd:d9:dd:c25:c25a:d00a:191b/1282c19:dd:d9:dd:c25:c25a:d00a:191b
292c19:dd:d9:dd:c25:c25a:d00a:191c/1282c19:dd:d9:dd:c25:c25a:d00a:191c
302c19:dd:d9:dd:c25:c25a:d00a:191d/1282c19:dd:d9:dd:c25:c25a:d00a:191d
312c19:dd:d9:dd:c25:c25a:d00a:191e/1282c19:dd:d9:dd:c25:c25a:d00a:191e
322c19:dd:d9:dd:c25:c25a:d00a:191f/1282c19:dd:d9:dd:c25:c25a:d00a:191f
332c19:dd:d9:dd:c25:c25a:d00a:1920/1282c19:dd:d9:dd:c25:c25a:d00a:1920
342c19:dd:d9:dd:c25:c25a:d00a:1921/1282c19:dd:d9:dd:c25:c25a:d00a:1921
352c19:dd:d9:dd:c25:c25a:d00a:1922/1282c19:dd:d9:dd:c25:c25a:d00a:1922
362c19:dd:d9:dd:c25:c25a:d00a:1923/1282c19:dd:d9:dd:c25:c25a:d00a:1923
372c19:dd:d9:dd:c25:c25a:d00a:1924/1282c19:dd:d9:dd:c25:c25a:d00a:1924
382c19:dd:d9:dd:c25:c25a:d00a:1925/1282c19:dd:d9:dd:c25:c25a:d00a:1925
392c19:dd:d9:dd:c25:c25a:d00a:1926/1282c19:dd:d9:dd:c25:c25a:d00a:1926
402c19:dd:d9:dd:c25:c25a:d00a:1927/1282c19:dd:d9:dd:c25:c25a:d00a:1927
412c19:dd:d9:dd:c25:c25a:d00a:1928/1282c19:dd:d9:dd:c25:c25a:d00a:1928
422c19:dd:d9:dd:c25:c25a:d00a:1929/1282c19:dd:d9:dd:c25:c25a:d00a:1929
432c19:dd:d9:dd:c25:c25a:d00a:192a/1282c19:dd:d9:dd:c25:c25a:d00a:192a
442c19:dd:d9:dd:c25:c25a:d00a:192b/1282c19:dd:d9:dd:c25:c25a:d00a:192b
452c19:dd:d9:dd:c25:c25a:d00a:192c/1282c19:dd:d9:dd:c25:c25a:d00a:192c
462c19:dd:d9:dd:c25:c25a:d00a:192d/1282c19:dd:d9:dd:c25:c25a:d00a:192d
472c19:dd:d9:dd:c25:c25a:d00a:192e/1282c19:dd:d9:dd:c25:c25a:d00a:192e
482c19:dd:d9:dd:c25:c25a:d00a:192f/1282c19:dd:d9:dd:c25:c25a:d00a:192f
492c19:dd:d9:dd:c25:c25a:d00a:1930/1282c19:dd:d9:dd:c25:c25a:d00a:1930
502c19:dd:d9:dd:c25:c25a:d00a:1931/1282c19:dd:d9:dd:c25:c25a:d00a:1931
512c19:dd:d9:dd:c25:c25a:d00a:1932/1282c19:dd:d9:dd:c25:c25a:d00a:1932
522c19:dd:d9:dd:c25:c25a:d00a:1933/1282c19:dd:d9:dd:c25:c25a:d00a:1933
532c19:dd:d9:dd:c25:c25a:d00a:1934/1282c19:dd:d9:dd:c25:c25a:d00a:1934
542c19:dd:d9:dd:c25:c25a:d00a:1935/1282c19:dd:d9:dd:c25:c25a:d00a:1935
552c19:dd:d9:dd:c25:c25a:d00a:1936/1282c19:dd:d9:dd:c25:c25a:d00a:1936
562c19:dd:d9:dd:c25:c25a:d00a:1937/1282c19:dd:d9:dd:c25:c25a:d00a:1937
572c19:dd:d9:dd:c25:c25a:d00a:1938/1282c19:dd:d9:dd:c25:c25a:d00a:1938
582c19:dd:d9:dd:c25:c25a:d00a:1939/1282c19:dd:d9:dd:c25:c25a:d00a:1939
592c19:dd:d9:dd:c25:c25a:d00a:193a/1282c19:dd:d9:dd:c25:c25a:d00a:193a
602c19:dd:d9:dd:c25:c25a:d00a:193b/1282c19:dd:d9:dd:c25:c25a:d00a:193b
612c19:dd:d9:dd:c25:c25a:d00a:193c/1282c19:dd:d9:dd:c25:c25a:d00a:193c
622c19:dd:d9:dd:c25:c25a:d00a:193d/1282c19:dd:d9:dd:c25:c25a:d00a:193d
632c19:dd:d9:dd:c25:c25a:d00a:193e/1282c19:dd:d9:dd:c25:c25a:d00a:193e
642c19:dd:d9:dd:c25:c25a:d00a:193f/1282c19:dd:d9:dd:c25:c25a:d00a:193f
652c19:dd:d9:dd:c25:c25a:d00a:1940/1282c19:dd:d9:dd:c25:c25a:d00a:1940
662c19:dd:d9:dd:c25:c25a:d00a:1941/1282c19:dd:d9:dd:c25:c25a:d00a:1941
672c19:dd:d9:dd:c25:c25a:d00a:1942/1282c19:dd:d9:dd:c25:c25a:d00a:1942
682c19:dd:d9:dd:c25:c25a:d00a:1943/1282c19:dd:d9:dd:c25:c25a:d00a:1943
692c19:dd:d9:dd:c25:c25a:d00a:1944/1282c19:dd:d9:dd:c25:c25a:d00a:1944
702c19:dd:d9:dd:c25:c25a:d00a:1945/1282c19:dd:d9:dd:c25:c25a:d00a:1945
712c19:dd:d9:dd:c25:c25a:d00a:1946/1282c19:dd:d9:dd:c25:c25a:d00a:1946
722c19:dd:d9:dd:c25:c25a:d00a:1947/1282c19:dd:d9:dd:c25:c25a:d00a:1947
732c19:dd:d9:dd:c25:c25a:d00a:1948/1282c19:dd:d9:dd:c25:c25a:d00a:1948
742c19:dd:d9:dd:c25:c25a:d00a:1949/1282c19:dd:d9:dd:c25:c25a:d00a:1949
752c19:dd:d9:dd:c25:c25a:d00a:194a/1282c19:dd:d9:dd:c25:c25a:d00a:194a
762c19:dd:d9:dd:c25:c25a:d00a:194b/1282c19:dd:d9:dd:c25:c25a:d00a:194b
772c19:dd:d9:dd:c25:c25a:d00a:194c/1282c19:dd:d9:dd:c25:c25a:d00a:194c
782c19:dd:d9:dd:c25:c25a:d00a:194d/1282c19:dd:d9:dd:c25:c25a:d00a:194d
792c19:dd:d9:dd:c25:c25a:d00a:194e/1282c19:dd:d9:dd:c25:c25a:d00a:194e
802c19:dd:d9:dd:c25:c25a:d00a:194f/1282c19:dd:d9:dd:c25:c25a:d00a:194f
812c19:dd:d9:dd:c25:c25a:d00a:1950/1282c19:dd:d9:dd:c25:c25a:d00a:1950
822c19:dd:d9:dd:c25:c25a:d00a:1951/1282c19:dd:d9:dd:c25:c25a:d00a:1951
832c19:dd:d9:dd:c25:c25a:d00a:1952/1282c19:dd:d9:dd:c25:c25a:d00a:1952
842c19:dd:d9:dd:c25:c25a:d00a:1953/1282c19:dd:d9:dd:c25:c25a:d00a:1953
852c19:dd:d9:dd:c25:c25a:d00a:1954/1282c19:dd:d9:dd:c25:c25a:d00a:1954
862c19:dd:d9:dd:c25:c25a:d00a:1955/1282c19:dd:d9:dd:c25:c25a:d00a:1955
872c19:dd:d9:dd:c25:c25a:d00a:1956/1282c19:dd:d9:dd:c25:c25a:d00a:1956
882c19:dd:d9:dd:c25:c25a:d00a:1957/1282c19:dd:d9:dd:c25:c25a:d00a:1957
892c19:dd:d9:dd:c25:c25a:d00a:1958/1282c19:dd:d9:dd:c25:c25a:d00a:1958
902c19:dd:d9:dd:c25:c25a:d00a:1959/1282c19:dd:d9:dd:c25:c25a:d00a:1959
912c19:dd:d9:dd:c25:c25a:d00a:195a/1282c19:dd:d9:dd:c25:c25a:d00a:195a
922c19:dd:d9:dd:c25:c25a:d00a:195b/1282c19:dd:d9:dd:c25:c25a:d00a:195b
932c19:dd:d9:dd:c25:c25a:d00a:195c/1282c19:dd:d9:dd:c25:c25a:d00a:195c
942c19:dd:d9:dd:c25:c25a:d00a:195d/1282c19:dd:d9:dd:c25:c25a:d00a:195d
952c19:dd:d9:dd:c25:c25a:d00a:195e/1282c19:dd:d9:dd:c25:c25a:d00a:195e
962c19:dd:d9:dd:c25:c25a:d00a:195f/1282c19:dd:d9:dd:c25:c25a:d00a:195f
972c19:dd:d9:dd:c25:c25a:d00a:1960/1282c19:dd:d9:dd:c25:c25a:d00a:1960
982c19:dd:d9:dd:c25:c25a:d00a:1961/1282c19:dd:d9:dd:c25:c25a:d00a:1961
992c19:dd:d9:dd:c25:c25a:d00a:1962/1282c19:dd:d9:dd:c25:c25a:d00a:1962
1002c19:dd:d9:dd:c25:c25a:d00a:1963/1282c19:dd:d9:dd:c25:c25a:d00a:1963
1012c19:dd:d9:dd:c25:c25a:d00a:1964/1282c19:dd:d9:dd:c25:c25a:d00a:1964
1022c19:dd:d9:dd:c25:c25a:d00a:1965/1282c19:dd:d9:dd:c25:c25a:d00a:1965
1032c19:dd:d9:dd:c25:c25a:d00a:1966/1282c19:dd:d9:dd:c25:c25a:d00a:1966
1042c19:dd:d9:dd:c25:c25a:d00a:1967/1282c19:dd:d9:dd:c25:c25a:d00a:1967
1052c19:dd:d9:dd:c25:c25a:d00a:1968/1282c19:dd:d9:dd:c25:c25a:d00a:1968
1062c19:dd:d9:dd:c25:c25a:d00a:1969/1282c19:dd:d9:dd:c25:c25a:d00a:1969
1072c19:dd:d9:dd:c25:c25a:d00a:196a/1282c19:dd:d9:dd:c25:c25a:d00a:196a
1082c19:dd:d9:dd:c25:c25a:d00a:196b/1282c19:dd:d9:dd:c25:c25a:d00a:196b
1092c19:dd:d9:dd:c25:c25a:d00a:196c/1282c19:dd:d9:dd:c25:c25a:d00a:196c
1102c19:dd:d9:dd:c25:c25a:d00a:196d/1282c19:dd:d9:dd:c25:c25a:d00a:196d
1112c19:dd:d9:dd:c25:c25a:d00a:196e/1282c19:dd:d9:dd:c25:c25a:d00a:196e
1122c19:dd:d9:dd:c25:c25a:d00a:196f/1282c19:dd:d9:dd:c25:c25a:d00a:196f
1132c19:dd:d9:dd:c25:c25a:d00a:1970/1282c19:dd:d9:dd:c25:c25a:d00a:1970
1142c19:dd:d9:dd:c25:c25a:d00a:1971/1282c19:dd:d9:dd:c25:c25a:d00a:1971
1152c19:dd:d9:dd:c25:c25a:d00a:1972/1282c19:dd:d9:dd:c25:c25a:d00a:1972
1162c19:dd:d9:dd:c25:c25a:d00a:1973/1282c19:dd:d9:dd:c25:c25a:d00a:1973
1172c19:dd:d9:dd:c25:c25a:d00a:1974/1282c19:dd:d9:dd:c25:c25a:d00a:1974
1182c19:dd:d9:dd:c25:c25a:d00a:1975/1282c19:dd:d9:dd:c25:c25a:d00a:1975
1192c19:dd:d9:dd:c25:c25a:d00a:1976/1282c19:dd:d9:dd:c25:c25a:d00a:1976
1202c19:dd:d9:dd:c25:c25a:d00a:1977/1282c19:dd:d9:dd:c25:c25a:d00a:1977
1212c19:dd:d9:dd:c25:c25a:d00a:1978/1282c19:dd:d9:dd:c25:c25a:d00a:1978
1222c19:dd:d9:dd:c25:c25a:d00a:1979/1282c19:dd:d9:dd:c25:c25a:d00a:1979
1232c19:dd:d9:dd:c25:c25a:d00a:197a/1282c19:dd:d9:dd:c25:c25a:d00a:197a
1242c19:dd:d9:dd:c25:c25a:d00a:197b/1282c19:dd:d9:dd:c25:c25a:d00a:197b
1252c19:dd:d9:dd:c25:c25a:d00a:197c/1282c19:dd:d9:dd:c25:c25a:d00a:197c
1262c19:dd:d9:dd:c25:c25a:d00a:197d/1282c19:dd:d9:dd:c25:c25a:d00a:197d
1272c19:dd:d9:dd:c25:c25a:d00a:197e/1282c19:dd:d9:dd:c25:c25a:d00a:197e
1282c19:dd:d9:dd:c25:c25a:d00a:197f/1282c19:dd:d9:dd:c25:c25a:d00a:197f
1292c19:dd:d9:dd:c25:c25a:d00a:1980/1282c19:dd:d9:dd:c25:c25a:d00a:1980
1302c19:dd:d9:dd:c25:c25a:d00a:1981/1282c19:dd:d9:dd:c25:c25a:d00a:1981
1312c19:dd:d9:dd:c25:c25a:d00a:1982/1282c19:dd:d9:dd:c25:c25a:d00a:1982
1322c19:dd:d9:dd:c25:c25a:d00a:1983/1282c19:dd:d9:dd:c25:c25a:d00a:1983
1332c19:dd:d9:dd:c25:c25a:d00a:1984/1282c19:dd:d9:dd:c25:c25a:d00a:1984
1342c19:dd:d9:dd:c25:c25a:d00a:1985/1282c19:dd:d9:dd:c25:c25a:d00a:1985
1352c19:dd:d9:dd:c25:c25a:d00a:1986/1282c19:dd:d9:dd:c25:c25a:d00a:1986
1362c19:dd:d9:dd:c25:c25a:d00a:1987/1282c19:dd:d9:dd:c25:c25a:d00a:1987
1372c19:dd:d9:dd:c25:c25a:d00a:1988/1282c19:dd:d9:dd:c25:c25a:d00a:1988
1382c19:dd:d9:dd:c25:c25a:d00a:1989/1282c19:dd:d9:dd:c25:c25a:d00a:1989
1392c19:dd:d9:dd:c25:c25a:d00a:198a/1282c19:dd:d9:dd:c25:c25a:d00a:198a
1402c19:dd:d9:dd:c25:c25a:d00a:198b/1282c19:dd:d9:dd:c25:c25a:d00a:198b
1412c19:dd:d9:dd:c25:c25a:d00a:198c/1282c19:dd:d9:dd:c25:c25a:d00a:198c
1422c19:dd:d9:dd:c25:c25a:d00a:198d/1282c19:dd:d9:dd:c25:c25a:d00a:198d
1432c19:dd:d9:dd:c25:c25a:d00a:198e/1282c19:dd:d9:dd:c25:c25a:d00a:198e
1442c19:dd:d9:dd:c25:c25a:d00a:198f/1282c19:dd:d9:dd:c25:c25a:d00a:198f
1452c19:dd:d9:dd:c25:c25a:d00a:1990/1282c19:dd:d9:dd:c25:c25a:d00a:1990
1462c19:dd:d9:dd:c25:c25a:d00a:1991/1282c19:dd:d9:dd:c25:c25a:d00a:1991
1472c19:dd:d9:dd:c25:c25a:d00a:1992/1282c19:dd:d9:dd:c25:c25a:d00a:1992
1482c19:dd:d9:dd:c25:c25a:d00a:1993/1282c19:dd:d9:dd:c25:c25a:d00a:1993
1492c19:dd:d9:dd:c25:c25a:d00a:1994/1282c19:dd:d9:dd:c25:c25a:d00a:1994
1502c19:dd:d9:dd:c25:c25a:d00a:1995/1282c19:dd:d9:dd:c25:c25a:d00a:1995
1512c19:dd:d9:dd:c25:c25a:d00a:1996/1282c19:dd:d9:dd:c25:c25a:d00a:1996
1522c19:dd:d9:dd:c25:c25a:d00a:1997/1282c19:dd:d9:dd:c25:c25a:d00a:1997
1532c19:dd:d9:dd:c25:c25a:d00a:1998/1282c19:dd:d9:dd:c25:c25a:d00a:1998
1542c19:dd:d9:dd:c25:c25a:d00a:1999/1282c19:dd:d9:dd:c25:c25a:d00a:1999
1552c19:dd:d9:dd:c25:c25a:d00a:199a/1282c19:dd:d9:dd:c25:c25a:d00a:199a
1562c19:dd:d9:dd:c25:c25a:d00a:199b/1282c19:dd:d9:dd:c25:c25a:d00a:199b
1572c19:dd:d9:dd:c25:c25a:d00a:199c/1282c19:dd:d9:dd:c25:c25a:d00a:199c
1582c19:dd:d9:dd:c25:c25a:d00a:199d/1282c19:dd:d9:dd:c25:c25a:d00a:199d
1592c19:dd:d9:dd:c25:c25a:d00a:199e/1282c19:dd:d9:dd:c25:c25a:d00a:199e
1602c19:dd:d9:dd:c25:c25a:d00a:199f/1282c19:dd:d9:dd:c25:c25a:d00a:199f
1612c19:dd:d9:dd:c25:c25a:d00a:19a0/1282c19:dd:d9:dd:c25:c25a:d00a:19a0
1622c19:dd:d9:dd:c25:c25a:d00a:19a1/1282c19:dd:d9:dd:c25:c25a:d00a:19a1
1632c19:dd:d9:dd:c25:c25a:d00a:19a2/1282c19:dd:d9:dd:c25:c25a:d00a:19a2
1642c19:dd:d9:dd:c25:c25a:d00a:19a3/1282c19:dd:d9:dd:c25:c25a:d00a:19a3
1652c19:dd:d9:dd:c25:c25a:d00a:19a4/1282c19:dd:d9:dd:c25:c25a:d00a:19a4
1662c19:dd:d9:dd:c25:c25a:d00a:19a5/1282c19:dd:d9:dd:c25:c25a:d00a:19a5
1672c19:dd:d9:dd:c25:c25a:d00a:19a6/1282c19:dd:d9:dd:c25:c25a:d00a:19a6
1682c19:dd:d9:dd:c25:c25a:d00a:19a7/1282c19:dd:d9:dd:c25:c25a:d00a:19a7
1692c19:dd:d9:dd:c25:c25a:d00a:19a8/1282c19:dd:d9:dd:c25:c25a:d00a:19a8
1702c19:dd:d9:dd:c25:c25a:d00a:19a9/1282c19:dd:d9:dd:c25:c25a:d00a:19a9
1712c19:dd:d9:dd:c25:c25a:d00a:19aa/1282c19:dd:d9:dd:c25:c25a:d00a:19aa
1722c19:dd:d9:dd:c25:c25a:d00a:19ab/1282c19:dd:d9:dd:c25:c25a:d00a:19ab
1732c19:dd:d9:dd:c25:c25a:d00a:19ac/1282c19:dd:d9:dd:c25:c25a:d00a:19ac
1742c19:dd:d9:dd:c25:c25a:d00a:19ad/1282c19:dd:d9:dd:c25:c25a:d00a:19ad
1752c19:dd:d9:dd:c25:c25a:d00a:19ae/1282c19:dd:d9:dd:c25:c25a:d00a:19ae
1762c19:dd:d9:dd:c25:c25a:d00a:19af/1282c19:dd:d9:dd:c25:c25a:d00a:19af
1772c19:dd:d9:dd:c25:c25a:d00a:19b0/1282c19:dd:d9:dd:c25:c25a:d00a:19b0
1782c19:dd:d9:dd:c25:c25a:d00a:19b1/1282c19:dd:d9:dd:c25:c25a:d00a:19b1
1792c19:dd:d9:dd:c25:c25a:d00a:19b2/1282c19:dd:d9:dd:c25:c25a:d00a:19b2
1802c19:dd:d9:dd:c25:c25a:d00a:19b3/1282c19:dd:d9:dd:c25:c25a:d00a:19b3
1812c19:dd:d9:dd:c25:c25a:d00a:19b4/1282c19:dd:d9:dd:c25:c25a:d00a:19b4
1822c19:dd:d9:dd:c25:c25a:d00a:19b5/1282c19:dd:d9:dd:c25:c25a:d00a:19b5
1832c19:dd:d9:dd:c25:c25a:d00a:19b6/1282c19:dd:d9:dd:c25:c25a:d00a:19b6
1842c19:dd:d9:dd:c25:c25a:d00a:19b7/1282c19:dd:d9:dd:c25:c25a:d00a:19b7
1852c19:dd:d9:dd:c25:c25a:d00a:19b8/1282c19:dd:d9:dd:c25:c25a:d00a:19b8
1862c19:dd:d9:dd:c25:c25a:d00a:19b9/1282c19:dd:d9:dd:c25:c25a:d00a:19b9
1872c19:dd:d9:dd:c25:c25a:d00a:19ba/1282c19:dd:d9:dd:c25:c25a:d00a:19ba
1882c19:dd:d9:dd:c25:c25a:d00a:19bb/1282c19:dd:d9:dd:c25:c25a:d00a:19bb
1892c19:dd:d9:dd:c25:c25a:d00a:19bc/1282c19:dd:d9:dd:c25:c25a:d00a:19bc
1902c19:dd:d9:dd:c25:c25a:d00a:19bd/1282c19:dd:d9:dd:c25:c25a:d00a:19bd
1912c19:dd:d9:dd:c25:c25a:d00a:19be/1282c19:dd:d9:dd:c25:c25a:d00a:19be
1922c19:dd:d9:dd:c25:c25a:d00a:19bf/1282c19:dd:d9:dd:c25:c25a:d00a:19bf
1932c19:dd:d9:dd:c25:c25a:d00a:19c0/1282c19:dd:d9:dd:c25:c25a:d00a:19c0
1942c19:dd:d9:dd:c25:c25a:d00a:19c1/1282c19:dd:d9:dd:c25:c25a:d00a:19c1
1952c19:dd:d9:dd:c25:c25a:d00a:19c2/1282c19:dd:d9:dd:c25:c25a:d00a:19c2
1962c19:dd:d9:dd:c25:c25a:d00a:19c3/1282c19:dd:d9:dd:c25:c25a:d00a:19c3
1972c19:dd:d9:dd:c25:c25a:d00a:19c4/1282c19:dd:d9:dd:c25:c25a:d00a:19c4
1982c19:dd:d9:dd:c25:c25a:d00a:19c5/1282c19:dd:d9:dd:c25:c25a:d00a:19c5
1992c19:dd:d9:dd:c25:c25a:d00a:19c6/1282c19:dd:d9:dd:c25:c25a:d00a:19c6
2002c19:dd:d9:dd:c25:c25a:d00a:19c7/1282c19:dd:d9:dd:c25:c25a:d00a:19c7
2012c19:dd:d9:dd:c25:c25a:d00a:19c8/1282c19:dd:d9:dd:c25:c25a:d00a:19c8
2022c19:dd:d9:dd:c25:c25a:d00a:19c9/1282c19:dd:d9:dd:c25:c25a:d00a:19c9
2032c19:dd:d9:dd:c25:c25a:d00a:19ca/1282c19:dd:d9:dd:c25:c25a:d00a:19ca
2042c19:dd:d9:dd:c25:c25a:d00a:19cb/1282c19:dd:d9:dd:c25:c25a:d00a:19cb
2052c19:dd:d9:dd:c25:c25a:d00a:19cc/1282c19:dd:d9:dd:c25:c25a:d00a:19cc
2062c19:dd:d9:dd:c25:c25a:d00a:19cd/1282c19:dd:d9:dd:c25:c25a:d00a:19cd
2072c19:dd:d9:dd:c25:c25a:d00a:19ce/1282c19:dd:d9:dd:c25:c25a:d00a:19ce
2082c19:dd:d9:dd:c25:c25a:d00a:19cf/1282c19:dd:d9:dd:c25:c25a:d00a:19cf
2092c19:dd:d9:dd:c25:c25a:d00a:19d0/1282c19:dd:d9:dd:c25:c25a:d00a:19d0
2102c19:dd:d9:dd:c25:c25a:d00a:19d1/1282c19:dd:d9:dd:c25:c25a:d00a:19d1
2112c19:dd:d9:dd:c25:c25a:d00a:19d2/1282c19:dd:d9:dd:c25:c25a:d00a:19d2
2122c19:dd:d9:dd:c25:c25a:d00a:19d3/1282c19:dd:d9:dd:c25:c25a:d00a:19d3
2132c19:dd:d9:dd:c25:c25a:d00a:19d4/1282c19:dd:d9:dd:c25:c25a:d00a:19d4
2142c19:dd:d9:dd:c25:c25a:d00a:19d5/1282c19:dd:d9:dd:c25:c25a:d00a:19d5
2152c19:dd:d9:dd:c25:c25a:d00a:19d6/1282c19:dd:d9:dd:c25:c25a:d00a:19d6
2162c19:dd:d9:dd:c25:c25a:d00a:19d7/1282c19:dd:d9:dd:c25:c25a:d00a:19d7
2172c19:dd:d9:dd:c25:c25a:d00a:19d8/1282c19:dd:d9:dd:c25:c25a:d00a:19d8
2182c19:dd:d9:dd:c25:c25a:d00a:19d9/1282c19:dd:d9:dd:c25:c25a:d00a:19d9
2192c19:dd:d9:dd:c25:c25a:d00a:19da/1282c19:dd:d9:dd:c25:c25a:d00a:19da
2202c19:dd:d9:dd:c25:c25a:d00a:19db/1282c19:dd:d9:dd:c25:c25a:d00a:19db
2212c19:dd:d9:dd:c25:c25a:d00a:19dc/1282c19:dd:d9:dd:c25:c25a:d00a:19dc
2222c19:dd:d9:dd:c25:c25a:d00a:19dd/1282c19:dd:d9:dd:c25:c25a:d00a:19dd
2232c19:dd:d9:dd:c25:c25a:d00a:19de/1282c19:dd:d9:dd:c25:c25a:d00a:19de
2242c19:dd:d9:dd:c25:c25a:d00a:19df/1282c19:dd:d9:dd:c25:c25a:d00a:19df
2252c19:dd:d9:dd:c25:c25a:d00a:19e0/1282c19:dd:d9:dd:c25:c25a:d00a:19e0
2262c19:dd:d9:dd:c25:c25a:d00a:19e1/1282c19:dd:d9:dd:c25:c25a:d00a:19e1
2272c19:dd:d9:dd:c25:c25a:d00a:19e2/1282c19:dd:d9:dd:c25:c25a:d00a:19e2
2282c19:dd:d9:dd:c25:c25a:d00a:19e3/1282c19:dd:d9:dd:c25:c25a:d00a:19e3
2292c19:dd:d9:dd:c25:c25a:d00a:19e4/1282c19:dd:d9:dd:c25:c25a:d00a:19e4
2302c19:dd:d9:dd:c25:c25a:d00a:19e5/1282c19:dd:d9:dd:c25:c25a:d00a:19e5
2312c19:dd:d9:dd:c25:c25a:d00a:19e6/1282c19:dd:d9:dd:c25:c25a:d00a:19e6
2322c19:dd:d9:dd:c25:c25a:d00a:19e7/1282c19:dd:d9:dd:c25:c25a:d00a:19e7
2332c19:dd:d9:dd:c25:c25a:d00a:19e8/1282c19:dd:d9:dd:c25:c25a:d00a:19e8
2342c19:dd:d9:dd:c25:c25a:d00a:19e9/1282c19:dd:d9:dd:c25:c25a:d00a:19e9
2352c19:dd:d9:dd:c25:c25a:d00a:19ea/1282c19:dd:d9:dd:c25:c25a:d00a:19ea
2362c19:dd:d9:dd:c25:c25a:d00a:19eb/1282c19:dd:d9:dd:c25:c25a:d00a:19eb
2372c19:dd:d9:dd:c25:c25a:d00a:19ec/1282c19:dd:d9:dd:c25:c25a:d00a:19ec
2382c19:dd:d9:dd:c25:c25a:d00a:19ed/1282c19:dd:d9:dd:c25:c25a:d00a:19ed
2392c19:dd:d9:dd:c25:c25a:d00a:19ee/1282c19:dd:d9:dd:c25:c25a:d00a:19ee
2402c19:dd:d9:dd:c25:c25a:d00a:19ef/1282c19:dd:d9:dd:c25:c25a:d00a:19ef
2412c19:dd:d9:dd:c25:c25a:d00a:19f0/1282c19:dd:d9:dd:c25:c25a:d00a:19f0
2422c19:dd:d9:dd:c25:c25a:d00a:19f1/1282c19:dd:d9:dd:c25:c25a:d00a:19f1
2432c19:dd:d9:dd:c25:c25a:d00a:19f2/1282c19:dd:d9:dd:c25:c25a:d00a:19f2
2442c19:dd:d9:dd:c25:c25a:d00a:19f3/1282c19:dd:d9:dd:c25:c25a:d00a:19f3
2452c19:dd:d9:dd:c25:c25a:d00a:19f4/1282c19:dd:d9:dd:c25:c25a:d00a:19f4
2462c19:dd:d9:dd:c25:c25a:d00a:19f5/1282c19:dd:d9:dd:c25:c25a:d00a:19f5
2472c19:dd:d9:dd:c25:c25a:d00a:19f6/1282c19:dd:d9:dd:c25:c25a:d00a:19f6
2482c19:dd:d9:dd:c25:c25a:d00a:19f7/1282c19:dd:d9:dd:c25:c25a:d00a:19f7
2492c19:dd:d9:dd:c25:c25a:d00a:19f8/1282c19:dd:d9:dd:c25:c25a:d00a:19f8
2502c19:dd:d9:dd:c25:c25a:d00a:19f9/1282c19:dd:d9:dd:c25:c25a:d00a:19f9
2512c19:dd:d9:dd:c25:c25a:d00a:19fa/1282c19:dd:d9:dd:c25:c25a:d00a:19fa
2522c19:dd:d9:dd:c25:c25a:d00a:19fb/1282c19:dd:d9:dd:c25:c25a:d00a:19fb
2532c19:dd:d9:dd:c25:c25a:d00a:19fc/1282c19:dd:d9:dd:c25:c25a:d00a:19fc
2542c19:dd:d9:dd:c25:c25a:d00a:19fd/1282c19:dd:d9:dd:c25:c25a:d00a:19fd
2552c19:dd:d9:dd:c25:c25a:d00a:19fe/1282c19:dd:d9:dd:c25:c25a:d00a:19fe
2562c19:dd:d9:dd:c25:c25a:d00a:19ff/1282c19:dd:d9:dd:c25:c25a:d00a:19ff

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.