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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:5200/120
First address
2c19:dd:d9:dd:c25:c25:94de:5200
Last address
2c19:dd:d9:dd:c25:c25:94de:52ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:00d9:00dd:0c25:0c25:94de:5200
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
2.5.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:5200/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:d9:dd:c25:c25:94de:5200/1282c19:dd:d9:dd:c25:c25:94de:5200
22c19:dd:d9:dd:c25:c25:94de:5201/1282c19:dd:d9:dd:c25:c25:94de:5201
32c19:dd:d9:dd:c25:c25:94de:5202/1282c19:dd:d9:dd:c25:c25:94de:5202
42c19:dd:d9:dd:c25:c25:94de:5203/1282c19:dd:d9:dd:c25:c25:94de:5203
52c19:dd:d9:dd:c25:c25:94de:5204/1282c19:dd:d9:dd:c25:c25:94de:5204
62c19:dd:d9:dd:c25:c25:94de:5205/1282c19:dd:d9:dd:c25:c25:94de:5205
72c19:dd:d9:dd:c25:c25:94de:5206/1282c19:dd:d9:dd:c25:c25:94de:5206
82c19:dd:d9:dd:c25:c25:94de:5207/1282c19:dd:d9:dd:c25:c25:94de:5207
92c19:dd:d9:dd:c25:c25:94de:5208/1282c19:dd:d9:dd:c25:c25:94de:5208
102c19:dd:d9:dd:c25:c25:94de:5209/1282c19:dd:d9:dd:c25:c25:94de:5209
112c19:dd:d9:dd:c25:c25:94de:520a/1282c19:dd:d9:dd:c25:c25:94de:520a
122c19:dd:d9:dd:c25:c25:94de:520b/1282c19:dd:d9:dd:c25:c25:94de:520b
132c19:dd:d9:dd:c25:c25:94de:520c/1282c19:dd:d9:dd:c25:c25:94de:520c
142c19:dd:d9:dd:c25:c25:94de:520d/1282c19:dd:d9:dd:c25:c25:94de:520d
152c19:dd:d9:dd:c25:c25:94de:520e/1282c19:dd:d9:dd:c25:c25:94de:520e
162c19:dd:d9:dd:c25:c25:94de:520f/1282c19:dd:d9:dd:c25:c25:94de:520f
172c19:dd:d9:dd:c25:c25:94de:5210/1282c19:dd:d9:dd:c25:c25:94de:5210
182c19:dd:d9:dd:c25:c25:94de:5211/1282c19:dd:d9:dd:c25:c25:94de:5211
192c19:dd:d9:dd:c25:c25:94de:5212/1282c19:dd:d9:dd:c25:c25:94de:5212
202c19:dd:d9:dd:c25:c25:94de:5213/1282c19:dd:d9:dd:c25:c25:94de:5213
212c19:dd:d9:dd:c25:c25:94de:5214/1282c19:dd:d9:dd:c25:c25:94de:5214
222c19:dd:d9:dd:c25:c25:94de:5215/1282c19:dd:d9:dd:c25:c25:94de:5215
232c19:dd:d9:dd:c25:c25:94de:5216/1282c19:dd:d9:dd:c25:c25:94de:5216
242c19:dd:d9:dd:c25:c25:94de:5217/1282c19:dd:d9:dd:c25:c25:94de:5217
252c19:dd:d9:dd:c25:c25:94de:5218/1282c19:dd:d9:dd:c25:c25:94de:5218
262c19:dd:d9:dd:c25:c25:94de:5219/1282c19:dd:d9:dd:c25:c25:94de:5219
272c19:dd:d9:dd:c25:c25:94de:521a/1282c19:dd:d9:dd:c25:c25:94de:521a
282c19:dd:d9:dd:c25:c25:94de:521b/1282c19:dd:d9:dd:c25:c25:94de:521b
292c19:dd:d9:dd:c25:c25:94de:521c/1282c19:dd:d9:dd:c25:c25:94de:521c
302c19:dd:d9:dd:c25:c25:94de:521d/1282c19:dd:d9:dd:c25:c25:94de:521d
312c19:dd:d9:dd:c25:c25:94de:521e/1282c19:dd:d9:dd:c25:c25:94de:521e
322c19:dd:d9:dd:c25:c25:94de:521f/1282c19:dd:d9:dd:c25:c25:94de:521f
332c19:dd:d9:dd:c25:c25:94de:5220/1282c19:dd:d9:dd:c25:c25:94de:5220
342c19:dd:d9:dd:c25:c25:94de:5221/1282c19:dd:d9:dd:c25:c25:94de:5221
352c19:dd:d9:dd:c25:c25:94de:5222/1282c19:dd:d9:dd:c25:c25:94de:5222
362c19:dd:d9:dd:c25:c25:94de:5223/1282c19:dd:d9:dd:c25:c25:94de:5223
372c19:dd:d9:dd:c25:c25:94de:5224/1282c19:dd:d9:dd:c25:c25:94de:5224
382c19:dd:d9:dd:c25:c25:94de:5225/1282c19:dd:d9:dd:c25:c25:94de:5225
392c19:dd:d9:dd:c25:c25:94de:5226/1282c19:dd:d9:dd:c25:c25:94de:5226
402c19:dd:d9:dd:c25:c25:94de:5227/1282c19:dd:d9:dd:c25:c25:94de:5227
412c19:dd:d9:dd:c25:c25:94de:5228/1282c19:dd:d9:dd:c25:c25:94de:5228
422c19:dd:d9:dd:c25:c25:94de:5229/1282c19:dd:d9:dd:c25:c25:94de:5229
432c19:dd:d9:dd:c25:c25:94de:522a/1282c19:dd:d9:dd:c25:c25:94de:522a
442c19:dd:d9:dd:c25:c25:94de:522b/1282c19:dd:d9:dd:c25:c25:94de:522b
452c19:dd:d9:dd:c25:c25:94de:522c/1282c19:dd:d9:dd:c25:c25:94de:522c
462c19:dd:d9:dd:c25:c25:94de:522d/1282c19:dd:d9:dd:c25:c25:94de:522d
472c19:dd:d9:dd:c25:c25:94de:522e/1282c19:dd:d9:dd:c25:c25:94de:522e
482c19:dd:d9:dd:c25:c25:94de:522f/1282c19:dd:d9:dd:c25:c25:94de:522f
492c19:dd:d9:dd:c25:c25:94de:5230/1282c19:dd:d9:dd:c25:c25:94de:5230
502c19:dd:d9:dd:c25:c25:94de:5231/1282c19:dd:d9:dd:c25:c25:94de:5231
512c19:dd:d9:dd:c25:c25:94de:5232/1282c19:dd:d9:dd:c25:c25:94de:5232
522c19:dd:d9:dd:c25:c25:94de:5233/1282c19:dd:d9:dd:c25:c25:94de:5233
532c19:dd:d9:dd:c25:c25:94de:5234/1282c19:dd:d9:dd:c25:c25:94de:5234
542c19:dd:d9:dd:c25:c25:94de:5235/1282c19:dd:d9:dd:c25:c25:94de:5235
552c19:dd:d9:dd:c25:c25:94de:5236/1282c19:dd:d9:dd:c25:c25:94de:5236
562c19:dd:d9:dd:c25:c25:94de:5237/1282c19:dd:d9:dd:c25:c25:94de:5237
572c19:dd:d9:dd:c25:c25:94de:5238/1282c19:dd:d9:dd:c25:c25:94de:5238
582c19:dd:d9:dd:c25:c25:94de:5239/1282c19:dd:d9:dd:c25:c25:94de:5239
592c19:dd:d9:dd:c25:c25:94de:523a/1282c19:dd:d9:dd:c25:c25:94de:523a
602c19:dd:d9:dd:c25:c25:94de:523b/1282c19:dd:d9:dd:c25:c25:94de:523b
612c19:dd:d9:dd:c25:c25:94de:523c/1282c19:dd:d9:dd:c25:c25:94de:523c
622c19:dd:d9:dd:c25:c25:94de:523d/1282c19:dd:d9:dd:c25:c25:94de:523d
632c19:dd:d9:dd:c25:c25:94de:523e/1282c19:dd:d9:dd:c25:c25:94de:523e
642c19:dd:d9:dd:c25:c25:94de:523f/1282c19:dd:d9:dd:c25:c25:94de:523f
652c19:dd:d9:dd:c25:c25:94de:5240/1282c19:dd:d9:dd:c25:c25:94de:5240
662c19:dd:d9:dd:c25:c25:94de:5241/1282c19:dd:d9:dd:c25:c25:94de:5241
672c19:dd:d9:dd:c25:c25:94de:5242/1282c19:dd:d9:dd:c25:c25:94de:5242
682c19:dd:d9:dd:c25:c25:94de:5243/1282c19:dd:d9:dd:c25:c25:94de:5243
692c19:dd:d9:dd:c25:c25:94de:5244/1282c19:dd:d9:dd:c25:c25:94de:5244
702c19:dd:d9:dd:c25:c25:94de:5245/1282c19:dd:d9:dd:c25:c25:94de:5245
712c19:dd:d9:dd:c25:c25:94de:5246/1282c19:dd:d9:dd:c25:c25:94de:5246
722c19:dd:d9:dd:c25:c25:94de:5247/1282c19:dd:d9:dd:c25:c25:94de:5247
732c19:dd:d9:dd:c25:c25:94de:5248/1282c19:dd:d9:dd:c25:c25:94de:5248
742c19:dd:d9:dd:c25:c25:94de:5249/1282c19:dd:d9:dd:c25:c25:94de:5249
752c19:dd:d9:dd:c25:c25:94de:524a/1282c19:dd:d9:dd:c25:c25:94de:524a
762c19:dd:d9:dd:c25:c25:94de:524b/1282c19:dd:d9:dd:c25:c25:94de:524b
772c19:dd:d9:dd:c25:c25:94de:524c/1282c19:dd:d9:dd:c25:c25:94de:524c
782c19:dd:d9:dd:c25:c25:94de:524d/1282c19:dd:d9:dd:c25:c25:94de:524d
792c19:dd:d9:dd:c25:c25:94de:524e/1282c19:dd:d9:dd:c25:c25:94de:524e
802c19:dd:d9:dd:c25:c25:94de:524f/1282c19:dd:d9:dd:c25:c25:94de:524f
812c19:dd:d9:dd:c25:c25:94de:5250/1282c19:dd:d9:dd:c25:c25:94de:5250
822c19:dd:d9:dd:c25:c25:94de:5251/1282c19:dd:d9:dd:c25:c25:94de:5251
832c19:dd:d9:dd:c25:c25:94de:5252/1282c19:dd:d9:dd:c25:c25:94de:5252
842c19:dd:d9:dd:c25:c25:94de:5253/1282c19:dd:d9:dd:c25:c25:94de:5253
852c19:dd:d9:dd:c25:c25:94de:5254/1282c19:dd:d9:dd:c25:c25:94de:5254
862c19:dd:d9:dd:c25:c25:94de:5255/1282c19:dd:d9:dd:c25:c25:94de:5255
872c19:dd:d9:dd:c25:c25:94de:5256/1282c19:dd:d9:dd:c25:c25:94de:5256
882c19:dd:d9:dd:c25:c25:94de:5257/1282c19:dd:d9:dd:c25:c25:94de:5257
892c19:dd:d9:dd:c25:c25:94de:5258/1282c19:dd:d9:dd:c25:c25:94de:5258
902c19:dd:d9:dd:c25:c25:94de:5259/1282c19:dd:d9:dd:c25:c25:94de:5259
912c19:dd:d9:dd:c25:c25:94de:525a/1282c19:dd:d9:dd:c25:c25:94de:525a
922c19:dd:d9:dd:c25:c25:94de:525b/1282c19:dd:d9:dd:c25:c25:94de:525b
932c19:dd:d9:dd:c25:c25:94de:525c/1282c19:dd:d9:dd:c25:c25:94de:525c
942c19:dd:d9:dd:c25:c25:94de:525d/1282c19:dd:d9:dd:c25:c25:94de:525d
952c19:dd:d9:dd:c25:c25:94de:525e/1282c19:dd:d9:dd:c25:c25:94de:525e
962c19:dd:d9:dd:c25:c25:94de:525f/1282c19:dd:d9:dd:c25:c25:94de:525f
972c19:dd:d9:dd:c25:c25:94de:5260/1282c19:dd:d9:dd:c25:c25:94de:5260
982c19:dd:d9:dd:c25:c25:94de:5261/1282c19:dd:d9:dd:c25:c25:94de:5261
992c19:dd:d9:dd:c25:c25:94de:5262/1282c19:dd:d9:dd:c25:c25:94de:5262
1002c19:dd:d9:dd:c25:c25:94de:5263/1282c19:dd:d9:dd:c25:c25:94de:5263
1012c19:dd:d9:dd:c25:c25:94de:5264/1282c19:dd:d9:dd:c25:c25:94de:5264
1022c19:dd:d9:dd:c25:c25:94de:5265/1282c19:dd:d9:dd:c25:c25:94de:5265
1032c19:dd:d9:dd:c25:c25:94de:5266/1282c19:dd:d9:dd:c25:c25:94de:5266
1042c19:dd:d9:dd:c25:c25:94de:5267/1282c19:dd:d9:dd:c25:c25:94de:5267
1052c19:dd:d9:dd:c25:c25:94de:5268/1282c19:dd:d9:dd:c25:c25:94de:5268
1062c19:dd:d9:dd:c25:c25:94de:5269/1282c19:dd:d9:dd:c25:c25:94de:5269
1072c19:dd:d9:dd:c25:c25:94de:526a/1282c19:dd:d9:dd:c25:c25:94de:526a
1082c19:dd:d9:dd:c25:c25:94de:526b/1282c19:dd:d9:dd:c25:c25:94de:526b
1092c19:dd:d9:dd:c25:c25:94de:526c/1282c19:dd:d9:dd:c25:c25:94de:526c
1102c19:dd:d9:dd:c25:c25:94de:526d/1282c19:dd:d9:dd:c25:c25:94de:526d
1112c19:dd:d9:dd:c25:c25:94de:526e/1282c19:dd:d9:dd:c25:c25:94de:526e
1122c19:dd:d9:dd:c25:c25:94de:526f/1282c19:dd:d9:dd:c25:c25:94de:526f
1132c19:dd:d9:dd:c25:c25:94de:5270/1282c19:dd:d9:dd:c25:c25:94de:5270
1142c19:dd:d9:dd:c25:c25:94de:5271/1282c19:dd:d9:dd:c25:c25:94de:5271
1152c19:dd:d9:dd:c25:c25:94de:5272/1282c19:dd:d9:dd:c25:c25:94de:5272
1162c19:dd:d9:dd:c25:c25:94de:5273/1282c19:dd:d9:dd:c25:c25:94de:5273
1172c19:dd:d9:dd:c25:c25:94de:5274/1282c19:dd:d9:dd:c25:c25:94de:5274
1182c19:dd:d9:dd:c25:c25:94de:5275/1282c19:dd:d9:dd:c25:c25:94de:5275
1192c19:dd:d9:dd:c25:c25:94de:5276/1282c19:dd:d9:dd:c25:c25:94de:5276
1202c19:dd:d9:dd:c25:c25:94de:5277/1282c19:dd:d9:dd:c25:c25:94de:5277
1212c19:dd:d9:dd:c25:c25:94de:5278/1282c19:dd:d9:dd:c25:c25:94de:5278
1222c19:dd:d9:dd:c25:c25:94de:5279/1282c19:dd:d9:dd:c25:c25:94de:5279
1232c19:dd:d9:dd:c25:c25:94de:527a/1282c19:dd:d9:dd:c25:c25:94de:527a
1242c19:dd:d9:dd:c25:c25:94de:527b/1282c19:dd:d9:dd:c25:c25:94de:527b
1252c19:dd:d9:dd:c25:c25:94de:527c/1282c19:dd:d9:dd:c25:c25:94de:527c
1262c19:dd:d9:dd:c25:c25:94de:527d/1282c19:dd:d9:dd:c25:c25:94de:527d
1272c19:dd:d9:dd:c25:c25:94de:527e/1282c19:dd:d9:dd:c25:c25:94de:527e
1282c19:dd:d9:dd:c25:c25:94de:527f/1282c19:dd:d9:dd:c25:c25:94de:527f
1292c19:dd:d9:dd:c25:c25:94de:5280/1282c19:dd:d9:dd:c25:c25:94de:5280
1302c19:dd:d9:dd:c25:c25:94de:5281/1282c19:dd:d9:dd:c25:c25:94de:5281
1312c19:dd:d9:dd:c25:c25:94de:5282/1282c19:dd:d9:dd:c25:c25:94de:5282
1322c19:dd:d9:dd:c25:c25:94de:5283/1282c19:dd:d9:dd:c25:c25:94de:5283
1332c19:dd:d9:dd:c25:c25:94de:5284/1282c19:dd:d9:dd:c25:c25:94de:5284
1342c19:dd:d9:dd:c25:c25:94de:5285/1282c19:dd:d9:dd:c25:c25:94de:5285
1352c19:dd:d9:dd:c25:c25:94de:5286/1282c19:dd:d9:dd:c25:c25:94de:5286
1362c19:dd:d9:dd:c25:c25:94de:5287/1282c19:dd:d9:dd:c25:c25:94de:5287
1372c19:dd:d9:dd:c25:c25:94de:5288/1282c19:dd:d9:dd:c25:c25:94de:5288
1382c19:dd:d9:dd:c25:c25:94de:5289/1282c19:dd:d9:dd:c25:c25:94de:5289
1392c19:dd:d9:dd:c25:c25:94de:528a/1282c19:dd:d9:dd:c25:c25:94de:528a
1402c19:dd:d9:dd:c25:c25:94de:528b/1282c19:dd:d9:dd:c25:c25:94de:528b
1412c19:dd:d9:dd:c25:c25:94de:528c/1282c19:dd:d9:dd:c25:c25:94de:528c
1422c19:dd:d9:dd:c25:c25:94de:528d/1282c19:dd:d9:dd:c25:c25:94de:528d
1432c19:dd:d9:dd:c25:c25:94de:528e/1282c19:dd:d9:dd:c25:c25:94de:528e
1442c19:dd:d9:dd:c25:c25:94de:528f/1282c19:dd:d9:dd:c25:c25:94de:528f
1452c19:dd:d9:dd:c25:c25:94de:5290/1282c19:dd:d9:dd:c25:c25:94de:5290
1462c19:dd:d9:dd:c25:c25:94de:5291/1282c19:dd:d9:dd:c25:c25:94de:5291
1472c19:dd:d9:dd:c25:c25:94de:5292/1282c19:dd:d9:dd:c25:c25:94de:5292
1482c19:dd:d9:dd:c25:c25:94de:5293/1282c19:dd:d9:dd:c25:c25:94de:5293
1492c19:dd:d9:dd:c25:c25:94de:5294/1282c19:dd:d9:dd:c25:c25:94de:5294
1502c19:dd:d9:dd:c25:c25:94de:5295/1282c19:dd:d9:dd:c25:c25:94de:5295
1512c19:dd:d9:dd:c25:c25:94de:5296/1282c19:dd:d9:dd:c25:c25:94de:5296
1522c19:dd:d9:dd:c25:c25:94de:5297/1282c19:dd:d9:dd:c25:c25:94de:5297
1532c19:dd:d9:dd:c25:c25:94de:5298/1282c19:dd:d9:dd:c25:c25:94de:5298
1542c19:dd:d9:dd:c25:c25:94de:5299/1282c19:dd:d9:dd:c25:c25:94de:5299
1552c19:dd:d9:dd:c25:c25:94de:529a/1282c19:dd:d9:dd:c25:c25:94de:529a
1562c19:dd:d9:dd:c25:c25:94de:529b/1282c19:dd:d9:dd:c25:c25:94de:529b
1572c19:dd:d9:dd:c25:c25:94de:529c/1282c19:dd:d9:dd:c25:c25:94de:529c
1582c19:dd:d9:dd:c25:c25:94de:529d/1282c19:dd:d9:dd:c25:c25:94de:529d
1592c19:dd:d9:dd:c25:c25:94de:529e/1282c19:dd:d9:dd:c25:c25:94de:529e
1602c19:dd:d9:dd:c25:c25:94de:529f/1282c19:dd:d9:dd:c25:c25:94de:529f
1612c19:dd:d9:dd:c25:c25:94de:52a0/1282c19:dd:d9:dd:c25:c25:94de:52a0
1622c19:dd:d9:dd:c25:c25:94de:52a1/1282c19:dd:d9:dd:c25:c25:94de:52a1
1632c19:dd:d9:dd:c25:c25:94de:52a2/1282c19:dd:d9:dd:c25:c25:94de:52a2
1642c19:dd:d9:dd:c25:c25:94de:52a3/1282c19:dd:d9:dd:c25:c25:94de:52a3
1652c19:dd:d9:dd:c25:c25:94de:52a4/1282c19:dd:d9:dd:c25:c25:94de:52a4
1662c19:dd:d9:dd:c25:c25:94de:52a5/1282c19:dd:d9:dd:c25:c25:94de:52a5
1672c19:dd:d9:dd:c25:c25:94de:52a6/1282c19:dd:d9:dd:c25:c25:94de:52a6
1682c19:dd:d9:dd:c25:c25:94de:52a7/1282c19:dd:d9:dd:c25:c25:94de:52a7
1692c19:dd:d9:dd:c25:c25:94de:52a8/1282c19:dd:d9:dd:c25:c25:94de:52a8
1702c19:dd:d9:dd:c25:c25:94de:52a9/1282c19:dd:d9:dd:c25:c25:94de:52a9
1712c19:dd:d9:dd:c25:c25:94de:52aa/1282c19:dd:d9:dd:c25:c25:94de:52aa
1722c19:dd:d9:dd:c25:c25:94de:52ab/1282c19:dd:d9:dd:c25:c25:94de:52ab
1732c19:dd:d9:dd:c25:c25:94de:52ac/1282c19:dd:d9:dd:c25:c25:94de:52ac
1742c19:dd:d9:dd:c25:c25:94de:52ad/1282c19:dd:d9:dd:c25:c25:94de:52ad
1752c19:dd:d9:dd:c25:c25:94de:52ae/1282c19:dd:d9:dd:c25:c25:94de:52ae
1762c19:dd:d9:dd:c25:c25:94de:52af/1282c19:dd:d9:dd:c25:c25:94de:52af
1772c19:dd:d9:dd:c25:c25:94de:52b0/1282c19:dd:d9:dd:c25:c25:94de:52b0
1782c19:dd:d9:dd:c25:c25:94de:52b1/1282c19:dd:d9:dd:c25:c25:94de:52b1
1792c19:dd:d9:dd:c25:c25:94de:52b2/1282c19:dd:d9:dd:c25:c25:94de:52b2
1802c19:dd:d9:dd:c25:c25:94de:52b3/1282c19:dd:d9:dd:c25:c25:94de:52b3
1812c19:dd:d9:dd:c25:c25:94de:52b4/1282c19:dd:d9:dd:c25:c25:94de:52b4
1822c19:dd:d9:dd:c25:c25:94de:52b5/1282c19:dd:d9:dd:c25:c25:94de:52b5
1832c19:dd:d9:dd:c25:c25:94de:52b6/1282c19:dd:d9:dd:c25:c25:94de:52b6
1842c19:dd:d9:dd:c25:c25:94de:52b7/1282c19:dd:d9:dd:c25:c25:94de:52b7
1852c19:dd:d9:dd:c25:c25:94de:52b8/1282c19:dd:d9:dd:c25:c25:94de:52b8
1862c19:dd:d9:dd:c25:c25:94de:52b9/1282c19:dd:d9:dd:c25:c25:94de:52b9
1872c19:dd:d9:dd:c25:c25:94de:52ba/1282c19:dd:d9:dd:c25:c25:94de:52ba
1882c19:dd:d9:dd:c25:c25:94de:52bb/1282c19:dd:d9:dd:c25:c25:94de:52bb
1892c19:dd:d9:dd:c25:c25:94de:52bc/1282c19:dd:d9:dd:c25:c25:94de:52bc
1902c19:dd:d9:dd:c25:c25:94de:52bd/1282c19:dd:d9:dd:c25:c25:94de:52bd
1912c19:dd:d9:dd:c25:c25:94de:52be/1282c19:dd:d9:dd:c25:c25:94de:52be
1922c19:dd:d9:dd:c25:c25:94de:52bf/1282c19:dd:d9:dd:c25:c25:94de:52bf
1932c19:dd:d9:dd:c25:c25:94de:52c0/1282c19:dd:d9:dd:c25:c25:94de:52c0
1942c19:dd:d9:dd:c25:c25:94de:52c1/1282c19:dd:d9:dd:c25:c25:94de:52c1
1952c19:dd:d9:dd:c25:c25:94de:52c2/1282c19:dd:d9:dd:c25:c25:94de:52c2
1962c19:dd:d9:dd:c25:c25:94de:52c3/1282c19:dd:d9:dd:c25:c25:94de:52c3
1972c19:dd:d9:dd:c25:c25:94de:52c4/1282c19:dd:d9:dd:c25:c25:94de:52c4
1982c19:dd:d9:dd:c25:c25:94de:52c5/1282c19:dd:d9:dd:c25:c25:94de:52c5
1992c19:dd:d9:dd:c25:c25:94de:52c6/1282c19:dd:d9:dd:c25:c25:94de:52c6
2002c19:dd:d9:dd:c25:c25:94de:52c7/1282c19:dd:d9:dd:c25:c25:94de:52c7
2012c19:dd:d9:dd:c25:c25:94de:52c8/1282c19:dd:d9:dd:c25:c25:94de:52c8
2022c19:dd:d9:dd:c25:c25:94de:52c9/1282c19:dd:d9:dd:c25:c25:94de:52c9
2032c19:dd:d9:dd:c25:c25:94de:52ca/1282c19:dd:d9:dd:c25:c25:94de:52ca
2042c19:dd:d9:dd:c25:c25:94de:52cb/1282c19:dd:d9:dd:c25:c25:94de:52cb
2052c19:dd:d9:dd:c25:c25:94de:52cc/1282c19:dd:d9:dd:c25:c25:94de:52cc
2062c19:dd:d9:dd:c25:c25:94de:52cd/1282c19:dd:d9:dd:c25:c25:94de:52cd
2072c19:dd:d9:dd:c25:c25:94de:52ce/1282c19:dd:d9:dd:c25:c25:94de:52ce
2082c19:dd:d9:dd:c25:c25:94de:52cf/1282c19:dd:d9:dd:c25:c25:94de:52cf
2092c19:dd:d9:dd:c25:c25:94de:52d0/1282c19:dd:d9:dd:c25:c25:94de:52d0
2102c19:dd:d9:dd:c25:c25:94de:52d1/1282c19:dd:d9:dd:c25:c25:94de:52d1
2112c19:dd:d9:dd:c25:c25:94de:52d2/1282c19:dd:d9:dd:c25:c25:94de:52d2
2122c19:dd:d9:dd:c25:c25:94de:52d3/1282c19:dd:d9:dd:c25:c25:94de:52d3
2132c19:dd:d9:dd:c25:c25:94de:52d4/1282c19:dd:d9:dd:c25:c25:94de:52d4
2142c19:dd:d9:dd:c25:c25:94de:52d5/1282c19:dd:d9:dd:c25:c25:94de:52d5
2152c19:dd:d9:dd:c25:c25:94de:52d6/1282c19:dd:d9:dd:c25:c25:94de:52d6
2162c19:dd:d9:dd:c25:c25:94de:52d7/1282c19:dd:d9:dd:c25:c25:94de:52d7
2172c19:dd:d9:dd:c25:c25:94de:52d8/1282c19:dd:d9:dd:c25:c25:94de:52d8
2182c19:dd:d9:dd:c25:c25:94de:52d9/1282c19:dd:d9:dd:c25:c25:94de:52d9
2192c19:dd:d9:dd:c25:c25:94de:52da/1282c19:dd:d9:dd:c25:c25:94de:52da
2202c19:dd:d9:dd:c25:c25:94de:52db/1282c19:dd:d9:dd:c25:c25:94de:52db
2212c19:dd:d9:dd:c25:c25:94de:52dc/1282c19:dd:d9:dd:c25:c25:94de:52dc
2222c19:dd:d9:dd:c25:c25:94de:52dd/1282c19:dd:d9:dd:c25:c25:94de:52dd
2232c19:dd:d9:dd:c25:c25:94de:52de/1282c19:dd:d9:dd:c25:c25:94de:52de
2242c19:dd:d9:dd:c25:c25:94de:52df/1282c19:dd:d9:dd:c25:c25:94de:52df
2252c19:dd:d9:dd:c25:c25:94de:52e0/1282c19:dd:d9:dd:c25:c25:94de:52e0
2262c19:dd:d9:dd:c25:c25:94de:52e1/1282c19:dd:d9:dd:c25:c25:94de:52e1
2272c19:dd:d9:dd:c25:c25:94de:52e2/1282c19:dd:d9:dd:c25:c25:94de:52e2
2282c19:dd:d9:dd:c25:c25:94de:52e3/1282c19:dd:d9:dd:c25:c25:94de:52e3
2292c19:dd:d9:dd:c25:c25:94de:52e4/1282c19:dd:d9:dd:c25:c25:94de:52e4
2302c19:dd:d9:dd:c25:c25:94de:52e5/1282c19:dd:d9:dd:c25:c25:94de:52e5
2312c19:dd:d9:dd:c25:c25:94de:52e6/1282c19:dd:d9:dd:c25:c25:94de:52e6
2322c19:dd:d9:dd:c25:c25:94de:52e7/1282c19:dd:d9:dd:c25:c25:94de:52e7
2332c19:dd:d9:dd:c25:c25:94de:52e8/1282c19:dd:d9:dd:c25:c25:94de:52e8
2342c19:dd:d9:dd:c25:c25:94de:52e9/1282c19:dd:d9:dd:c25:c25:94de:52e9
2352c19:dd:d9:dd:c25:c25:94de:52ea/1282c19:dd:d9:dd:c25:c25:94de:52ea
2362c19:dd:d9:dd:c25:c25:94de:52eb/1282c19:dd:d9:dd:c25:c25:94de:52eb
2372c19:dd:d9:dd:c25:c25:94de:52ec/1282c19:dd:d9:dd:c25:c25:94de:52ec
2382c19:dd:d9:dd:c25:c25:94de:52ed/1282c19:dd:d9:dd:c25:c25:94de:52ed
2392c19:dd:d9:dd:c25:c25:94de:52ee/1282c19:dd:d9:dd:c25:c25:94de:52ee
2402c19:dd:d9:dd:c25:c25:94de:52ef/1282c19:dd:d9:dd:c25:c25:94de:52ef
2412c19:dd:d9:dd:c25:c25:94de:52f0/1282c19:dd:d9:dd:c25:c25:94de:52f0
2422c19:dd:d9:dd:c25:c25:94de:52f1/1282c19:dd:d9:dd:c25:c25:94de:52f1
2432c19:dd:d9:dd:c25:c25:94de:52f2/1282c19:dd:d9:dd:c25:c25:94de:52f2
2442c19:dd:d9:dd:c25:c25:94de:52f3/1282c19:dd:d9:dd:c25:c25:94de:52f3
2452c19:dd:d9:dd:c25:c25:94de:52f4/1282c19:dd:d9:dd:c25:c25:94de:52f4
2462c19:dd:d9:dd:c25:c25:94de:52f5/1282c19:dd:d9:dd:c25:c25:94de:52f5
2472c19:dd:d9:dd:c25:c25:94de:52f6/1282c19:dd:d9:dd:c25:c25:94de:52f6
2482c19:dd:d9:dd:c25:c25:94de:52f7/1282c19:dd:d9:dd:c25:c25:94de:52f7
2492c19:dd:d9:dd:c25:c25:94de:52f8/1282c19:dd:d9:dd:c25:c25:94de:52f8
2502c19:dd:d9:dd:c25:c25:94de:52f9/1282c19:dd:d9:dd:c25:c25:94de:52f9
2512c19:dd:d9:dd:c25:c25:94de:52fa/1282c19:dd:d9:dd:c25:c25:94de:52fa
2522c19:dd:d9:dd:c25:c25:94de:52fb/1282c19:dd:d9:dd:c25:c25:94de:52fb
2532c19:dd:d9:dd:c25:c25:94de:52fc/1282c19:dd:d9:dd:c25:c25:94de:52fc
2542c19:dd:d9:dd:c25:c25:94de:52fd/1282c19:dd:d9:dd:c25:c25:94de:52fd
2552c19:dd:d9:dd:c25:c25:94de:52fe/1282c19:dd:d9:dd:c25:c25:94de:52fe
2562c19:dd:d9:dd:c25:c25:94de:52ff/1282c19:dd:d9:dd:c25:c25:94de:52ff

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.