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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:d915:1200/120
First address
2c19:dd:d9:dd:c25:c25:d915:1200
Last address
2c19:dd:d9:dd:c25:c25:d915:12ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:00d9:00dd:0c25:0c25:d915:1200
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
2.1.5.1.9.d.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:d915:1200/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:d9:dd:c25:c25:d915:1200/1282c19:dd:d9:dd:c25:c25:d915:1200
22c19:dd:d9:dd:c25:c25:d915:1201/1282c19:dd:d9:dd:c25:c25:d915:1201
32c19:dd:d9:dd:c25:c25:d915:1202/1282c19:dd:d9:dd:c25:c25:d915:1202
42c19:dd:d9:dd:c25:c25:d915:1203/1282c19:dd:d9:dd:c25:c25:d915:1203
52c19:dd:d9:dd:c25:c25:d915:1204/1282c19:dd:d9:dd:c25:c25:d915:1204
62c19:dd:d9:dd:c25:c25:d915:1205/1282c19:dd:d9:dd:c25:c25:d915:1205
72c19:dd:d9:dd:c25:c25:d915:1206/1282c19:dd:d9:dd:c25:c25:d915:1206
82c19:dd:d9:dd:c25:c25:d915:1207/1282c19:dd:d9:dd:c25:c25:d915:1207
92c19:dd:d9:dd:c25:c25:d915:1208/1282c19:dd:d9:dd:c25:c25:d915:1208
102c19:dd:d9:dd:c25:c25:d915:1209/1282c19:dd:d9:dd:c25:c25:d915:1209
112c19:dd:d9:dd:c25:c25:d915:120a/1282c19:dd:d9:dd:c25:c25:d915:120a
122c19:dd:d9:dd:c25:c25:d915:120b/1282c19:dd:d9:dd:c25:c25:d915:120b
132c19:dd:d9:dd:c25:c25:d915:120c/1282c19:dd:d9:dd:c25:c25:d915:120c
142c19:dd:d9:dd:c25:c25:d915:120d/1282c19:dd:d9:dd:c25:c25:d915:120d
152c19:dd:d9:dd:c25:c25:d915:120e/1282c19:dd:d9:dd:c25:c25:d915:120e
162c19:dd:d9:dd:c25:c25:d915:120f/1282c19:dd:d9:dd:c25:c25:d915:120f
172c19:dd:d9:dd:c25:c25:d915:1210/1282c19:dd:d9:dd:c25:c25:d915:1210
182c19:dd:d9:dd:c25:c25:d915:1211/1282c19:dd:d9:dd:c25:c25:d915:1211
192c19:dd:d9:dd:c25:c25:d915:1212/1282c19:dd:d9:dd:c25:c25:d915:1212
202c19:dd:d9:dd:c25:c25:d915:1213/1282c19:dd:d9:dd:c25:c25:d915:1213
212c19:dd:d9:dd:c25:c25:d915:1214/1282c19:dd:d9:dd:c25:c25:d915:1214
222c19:dd:d9:dd:c25:c25:d915:1215/1282c19:dd:d9:dd:c25:c25:d915:1215
232c19:dd:d9:dd:c25:c25:d915:1216/1282c19:dd:d9:dd:c25:c25:d915:1216
242c19:dd:d9:dd:c25:c25:d915:1217/1282c19:dd:d9:dd:c25:c25:d915:1217
252c19:dd:d9:dd:c25:c25:d915:1218/1282c19:dd:d9:dd:c25:c25:d915:1218
262c19:dd:d9:dd:c25:c25:d915:1219/1282c19:dd:d9:dd:c25:c25:d915:1219
272c19:dd:d9:dd:c25:c25:d915:121a/1282c19:dd:d9:dd:c25:c25:d915:121a
282c19:dd:d9:dd:c25:c25:d915:121b/1282c19:dd:d9:dd:c25:c25:d915:121b
292c19:dd:d9:dd:c25:c25:d915:121c/1282c19:dd:d9:dd:c25:c25:d915:121c
302c19:dd:d9:dd:c25:c25:d915:121d/1282c19:dd:d9:dd:c25:c25:d915:121d
312c19:dd:d9:dd:c25:c25:d915:121e/1282c19:dd:d9:dd:c25:c25:d915:121e
322c19:dd:d9:dd:c25:c25:d915:121f/1282c19:dd:d9:dd:c25:c25:d915:121f
332c19:dd:d9:dd:c25:c25:d915:1220/1282c19:dd:d9:dd:c25:c25:d915:1220
342c19:dd:d9:dd:c25:c25:d915:1221/1282c19:dd:d9:dd:c25:c25:d915:1221
352c19:dd:d9:dd:c25:c25:d915:1222/1282c19:dd:d9:dd:c25:c25:d915:1222
362c19:dd:d9:dd:c25:c25:d915:1223/1282c19:dd:d9:dd:c25:c25:d915:1223
372c19:dd:d9:dd:c25:c25:d915:1224/1282c19:dd:d9:dd:c25:c25:d915:1224
382c19:dd:d9:dd:c25:c25:d915:1225/1282c19:dd:d9:dd:c25:c25:d915:1225
392c19:dd:d9:dd:c25:c25:d915:1226/1282c19:dd:d9:dd:c25:c25:d915:1226
402c19:dd:d9:dd:c25:c25:d915:1227/1282c19:dd:d9:dd:c25:c25:d915:1227
412c19:dd:d9:dd:c25:c25:d915:1228/1282c19:dd:d9:dd:c25:c25:d915:1228
422c19:dd:d9:dd:c25:c25:d915:1229/1282c19:dd:d9:dd:c25:c25:d915:1229
432c19:dd:d9:dd:c25:c25:d915:122a/1282c19:dd:d9:dd:c25:c25:d915:122a
442c19:dd:d9:dd:c25:c25:d915:122b/1282c19:dd:d9:dd:c25:c25:d915:122b
452c19:dd:d9:dd:c25:c25:d915:122c/1282c19:dd:d9:dd:c25:c25:d915:122c
462c19:dd:d9:dd:c25:c25:d915:122d/1282c19:dd:d9:dd:c25:c25:d915:122d
472c19:dd:d9:dd:c25:c25:d915:122e/1282c19:dd:d9:dd:c25:c25:d915:122e
482c19:dd:d9:dd:c25:c25:d915:122f/1282c19:dd:d9:dd:c25:c25:d915:122f
492c19:dd:d9:dd:c25:c25:d915:1230/1282c19:dd:d9:dd:c25:c25:d915:1230
502c19:dd:d9:dd:c25:c25:d915:1231/1282c19:dd:d9:dd:c25:c25:d915:1231
512c19:dd:d9:dd:c25:c25:d915:1232/1282c19:dd:d9:dd:c25:c25:d915:1232
522c19:dd:d9:dd:c25:c25:d915:1233/1282c19:dd:d9:dd:c25:c25:d915:1233
532c19:dd:d9:dd:c25:c25:d915:1234/1282c19:dd:d9:dd:c25:c25:d915:1234
542c19:dd:d9:dd:c25:c25:d915:1235/1282c19:dd:d9:dd:c25:c25:d915:1235
552c19:dd:d9:dd:c25:c25:d915:1236/1282c19:dd:d9:dd:c25:c25:d915:1236
562c19:dd:d9:dd:c25:c25:d915:1237/1282c19:dd:d9:dd:c25:c25:d915:1237
572c19:dd:d9:dd:c25:c25:d915:1238/1282c19:dd:d9:dd:c25:c25:d915:1238
582c19:dd:d9:dd:c25:c25:d915:1239/1282c19:dd:d9:dd:c25:c25:d915:1239
592c19:dd:d9:dd:c25:c25:d915:123a/1282c19:dd:d9:dd:c25:c25:d915:123a
602c19:dd:d9:dd:c25:c25:d915:123b/1282c19:dd:d9:dd:c25:c25:d915:123b
612c19:dd:d9:dd:c25:c25:d915:123c/1282c19:dd:d9:dd:c25:c25:d915:123c
622c19:dd:d9:dd:c25:c25:d915:123d/1282c19:dd:d9:dd:c25:c25:d915:123d
632c19:dd:d9:dd:c25:c25:d915:123e/1282c19:dd:d9:dd:c25:c25:d915:123e
642c19:dd:d9:dd:c25:c25:d915:123f/1282c19:dd:d9:dd:c25:c25:d915:123f
652c19:dd:d9:dd:c25:c25:d915:1240/1282c19:dd:d9:dd:c25:c25:d915:1240
662c19:dd:d9:dd:c25:c25:d915:1241/1282c19:dd:d9:dd:c25:c25:d915:1241
672c19:dd:d9:dd:c25:c25:d915:1242/1282c19:dd:d9:dd:c25:c25:d915:1242
682c19:dd:d9:dd:c25:c25:d915:1243/1282c19:dd:d9:dd:c25:c25:d915:1243
692c19:dd:d9:dd:c25:c25:d915:1244/1282c19:dd:d9:dd:c25:c25:d915:1244
702c19:dd:d9:dd:c25:c25:d915:1245/1282c19:dd:d9:dd:c25:c25:d915:1245
712c19:dd:d9:dd:c25:c25:d915:1246/1282c19:dd:d9:dd:c25:c25:d915:1246
722c19:dd:d9:dd:c25:c25:d915:1247/1282c19:dd:d9:dd:c25:c25:d915:1247
732c19:dd:d9:dd:c25:c25:d915:1248/1282c19:dd:d9:dd:c25:c25:d915:1248
742c19:dd:d9:dd:c25:c25:d915:1249/1282c19:dd:d9:dd:c25:c25:d915:1249
752c19:dd:d9:dd:c25:c25:d915:124a/1282c19:dd:d9:dd:c25:c25:d915:124a
762c19:dd:d9:dd:c25:c25:d915:124b/1282c19:dd:d9:dd:c25:c25:d915:124b
772c19:dd:d9:dd:c25:c25:d915:124c/1282c19:dd:d9:dd:c25:c25:d915:124c
782c19:dd:d9:dd:c25:c25:d915:124d/1282c19:dd:d9:dd:c25:c25:d915:124d
792c19:dd:d9:dd:c25:c25:d915:124e/1282c19:dd:d9:dd:c25:c25:d915:124e
802c19:dd:d9:dd:c25:c25:d915:124f/1282c19:dd:d9:dd:c25:c25:d915:124f
812c19:dd:d9:dd:c25:c25:d915:1250/1282c19:dd:d9:dd:c25:c25:d915:1250
822c19:dd:d9:dd:c25:c25:d915:1251/1282c19:dd:d9:dd:c25:c25:d915:1251
832c19:dd:d9:dd:c25:c25:d915:1252/1282c19:dd:d9:dd:c25:c25:d915:1252
842c19:dd:d9:dd:c25:c25:d915:1253/1282c19:dd:d9:dd:c25:c25:d915:1253
852c19:dd:d9:dd:c25:c25:d915:1254/1282c19:dd:d9:dd:c25:c25:d915:1254
862c19:dd:d9:dd:c25:c25:d915:1255/1282c19:dd:d9:dd:c25:c25:d915:1255
872c19:dd:d9:dd:c25:c25:d915:1256/1282c19:dd:d9:dd:c25:c25:d915:1256
882c19:dd:d9:dd:c25:c25:d915:1257/1282c19:dd:d9:dd:c25:c25:d915:1257
892c19:dd:d9:dd:c25:c25:d915:1258/1282c19:dd:d9:dd:c25:c25:d915:1258
902c19:dd:d9:dd:c25:c25:d915:1259/1282c19:dd:d9:dd:c25:c25:d915:1259
912c19:dd:d9:dd:c25:c25:d915:125a/1282c19:dd:d9:dd:c25:c25:d915:125a
922c19:dd:d9:dd:c25:c25:d915:125b/1282c19:dd:d9:dd:c25:c25:d915:125b
932c19:dd:d9:dd:c25:c25:d915:125c/1282c19:dd:d9:dd:c25:c25:d915:125c
942c19:dd:d9:dd:c25:c25:d915:125d/1282c19:dd:d9:dd:c25:c25:d915:125d
952c19:dd:d9:dd:c25:c25:d915:125e/1282c19:dd:d9:dd:c25:c25:d915:125e
962c19:dd:d9:dd:c25:c25:d915:125f/1282c19:dd:d9:dd:c25:c25:d915:125f
972c19:dd:d9:dd:c25:c25:d915:1260/1282c19:dd:d9:dd:c25:c25:d915:1260
982c19:dd:d9:dd:c25:c25:d915:1261/1282c19:dd:d9:dd:c25:c25:d915:1261
992c19:dd:d9:dd:c25:c25:d915:1262/1282c19:dd:d9:dd:c25:c25:d915:1262
1002c19:dd:d9:dd:c25:c25:d915:1263/1282c19:dd:d9:dd:c25:c25:d915:1263
1012c19:dd:d9:dd:c25:c25:d915:1264/1282c19:dd:d9:dd:c25:c25:d915:1264
1022c19:dd:d9:dd:c25:c25:d915:1265/1282c19:dd:d9:dd:c25:c25:d915:1265
1032c19:dd:d9:dd:c25:c25:d915:1266/1282c19:dd:d9:dd:c25:c25:d915:1266
1042c19:dd:d9:dd:c25:c25:d915:1267/1282c19:dd:d9:dd:c25:c25:d915:1267
1052c19:dd:d9:dd:c25:c25:d915:1268/1282c19:dd:d9:dd:c25:c25:d915:1268
1062c19:dd:d9:dd:c25:c25:d915:1269/1282c19:dd:d9:dd:c25:c25:d915:1269
1072c19:dd:d9:dd:c25:c25:d915:126a/1282c19:dd:d9:dd:c25:c25:d915:126a
1082c19:dd:d9:dd:c25:c25:d915:126b/1282c19:dd:d9:dd:c25:c25:d915:126b
1092c19:dd:d9:dd:c25:c25:d915:126c/1282c19:dd:d9:dd:c25:c25:d915:126c
1102c19:dd:d9:dd:c25:c25:d915:126d/1282c19:dd:d9:dd:c25:c25:d915:126d
1112c19:dd:d9:dd:c25:c25:d915:126e/1282c19:dd:d9:dd:c25:c25:d915:126e
1122c19:dd:d9:dd:c25:c25:d915:126f/1282c19:dd:d9:dd:c25:c25:d915:126f
1132c19:dd:d9:dd:c25:c25:d915:1270/1282c19:dd:d9:dd:c25:c25:d915:1270
1142c19:dd:d9:dd:c25:c25:d915:1271/1282c19:dd:d9:dd:c25:c25:d915:1271
1152c19:dd:d9:dd:c25:c25:d915:1272/1282c19:dd:d9:dd:c25:c25:d915:1272
1162c19:dd:d9:dd:c25:c25:d915:1273/1282c19:dd:d9:dd:c25:c25:d915:1273
1172c19:dd:d9:dd:c25:c25:d915:1274/1282c19:dd:d9:dd:c25:c25:d915:1274
1182c19:dd:d9:dd:c25:c25:d915:1275/1282c19:dd:d9:dd:c25:c25:d915:1275
1192c19:dd:d9:dd:c25:c25:d915:1276/1282c19:dd:d9:dd:c25:c25:d915:1276
1202c19:dd:d9:dd:c25:c25:d915:1277/1282c19:dd:d9:dd:c25:c25:d915:1277
1212c19:dd:d9:dd:c25:c25:d915:1278/1282c19:dd:d9:dd:c25:c25:d915:1278
1222c19:dd:d9:dd:c25:c25:d915:1279/1282c19:dd:d9:dd:c25:c25:d915:1279
1232c19:dd:d9:dd:c25:c25:d915:127a/1282c19:dd:d9:dd:c25:c25:d915:127a
1242c19:dd:d9:dd:c25:c25:d915:127b/1282c19:dd:d9:dd:c25:c25:d915:127b
1252c19:dd:d9:dd:c25:c25:d915:127c/1282c19:dd:d9:dd:c25:c25:d915:127c
1262c19:dd:d9:dd:c25:c25:d915:127d/1282c19:dd:d9:dd:c25:c25:d915:127d
1272c19:dd:d9:dd:c25:c25:d915:127e/1282c19:dd:d9:dd:c25:c25:d915:127e
1282c19:dd:d9:dd:c25:c25:d915:127f/1282c19:dd:d9:dd:c25:c25:d915:127f
1292c19:dd:d9:dd:c25:c25:d915:1280/1282c19:dd:d9:dd:c25:c25:d915:1280
1302c19:dd:d9:dd:c25:c25:d915:1281/1282c19:dd:d9:dd:c25:c25:d915:1281
1312c19:dd:d9:dd:c25:c25:d915:1282/1282c19:dd:d9:dd:c25:c25:d915:1282
1322c19:dd:d9:dd:c25:c25:d915:1283/1282c19:dd:d9:dd:c25:c25:d915:1283
1332c19:dd:d9:dd:c25:c25:d915:1284/1282c19:dd:d9:dd:c25:c25:d915:1284
1342c19:dd:d9:dd:c25:c25:d915:1285/1282c19:dd:d9:dd:c25:c25:d915:1285
1352c19:dd:d9:dd:c25:c25:d915:1286/1282c19:dd:d9:dd:c25:c25:d915:1286
1362c19:dd:d9:dd:c25:c25:d915:1287/1282c19:dd:d9:dd:c25:c25:d915:1287
1372c19:dd:d9:dd:c25:c25:d915:1288/1282c19:dd:d9:dd:c25:c25:d915:1288
1382c19:dd:d9:dd:c25:c25:d915:1289/1282c19:dd:d9:dd:c25:c25:d915:1289
1392c19:dd:d9:dd:c25:c25:d915:128a/1282c19:dd:d9:dd:c25:c25:d915:128a
1402c19:dd:d9:dd:c25:c25:d915:128b/1282c19:dd:d9:dd:c25:c25:d915:128b
1412c19:dd:d9:dd:c25:c25:d915:128c/1282c19:dd:d9:dd:c25:c25:d915:128c
1422c19:dd:d9:dd:c25:c25:d915:128d/1282c19:dd:d9:dd:c25:c25:d915:128d
1432c19:dd:d9:dd:c25:c25:d915:128e/1282c19:dd:d9:dd:c25:c25:d915:128e
1442c19:dd:d9:dd:c25:c25:d915:128f/1282c19:dd:d9:dd:c25:c25:d915:128f
1452c19:dd:d9:dd:c25:c25:d915:1290/1282c19:dd:d9:dd:c25:c25:d915:1290
1462c19:dd:d9:dd:c25:c25:d915:1291/1282c19:dd:d9:dd:c25:c25:d915:1291
1472c19:dd:d9:dd:c25:c25:d915:1292/1282c19:dd:d9:dd:c25:c25:d915:1292
1482c19:dd:d9:dd:c25:c25:d915:1293/1282c19:dd:d9:dd:c25:c25:d915:1293
1492c19:dd:d9:dd:c25:c25:d915:1294/1282c19:dd:d9:dd:c25:c25:d915:1294
1502c19:dd:d9:dd:c25:c25:d915:1295/1282c19:dd:d9:dd:c25:c25:d915:1295
1512c19:dd:d9:dd:c25:c25:d915:1296/1282c19:dd:d9:dd:c25:c25:d915:1296
1522c19:dd:d9:dd:c25:c25:d915:1297/1282c19:dd:d9:dd:c25:c25:d915:1297
1532c19:dd:d9:dd:c25:c25:d915:1298/1282c19:dd:d9:dd:c25:c25:d915:1298
1542c19:dd:d9:dd:c25:c25:d915:1299/1282c19:dd:d9:dd:c25:c25:d915:1299
1552c19:dd:d9:dd:c25:c25:d915:129a/1282c19:dd:d9:dd:c25:c25:d915:129a
1562c19:dd:d9:dd:c25:c25:d915:129b/1282c19:dd:d9:dd:c25:c25:d915:129b
1572c19:dd:d9:dd:c25:c25:d915:129c/1282c19:dd:d9:dd:c25:c25:d915:129c
1582c19:dd:d9:dd:c25:c25:d915:129d/1282c19:dd:d9:dd:c25:c25:d915:129d
1592c19:dd:d9:dd:c25:c25:d915:129e/1282c19:dd:d9:dd:c25:c25:d915:129e
1602c19:dd:d9:dd:c25:c25:d915:129f/1282c19:dd:d9:dd:c25:c25:d915:129f
1612c19:dd:d9:dd:c25:c25:d915:12a0/1282c19:dd:d9:dd:c25:c25:d915:12a0
1622c19:dd:d9:dd:c25:c25:d915:12a1/1282c19:dd:d9:dd:c25:c25:d915:12a1
1632c19:dd:d9:dd:c25:c25:d915:12a2/1282c19:dd:d9:dd:c25:c25:d915:12a2
1642c19:dd:d9:dd:c25:c25:d915:12a3/1282c19:dd:d9:dd:c25:c25:d915:12a3
1652c19:dd:d9:dd:c25:c25:d915:12a4/1282c19:dd:d9:dd:c25:c25:d915:12a4
1662c19:dd:d9:dd:c25:c25:d915:12a5/1282c19:dd:d9:dd:c25:c25:d915:12a5
1672c19:dd:d9:dd:c25:c25:d915:12a6/1282c19:dd:d9:dd:c25:c25:d915:12a6
1682c19:dd:d9:dd:c25:c25:d915:12a7/1282c19:dd:d9:dd:c25:c25:d915:12a7
1692c19:dd:d9:dd:c25:c25:d915:12a8/1282c19:dd:d9:dd:c25:c25:d915:12a8
1702c19:dd:d9:dd:c25:c25:d915:12a9/1282c19:dd:d9:dd:c25:c25:d915:12a9
1712c19:dd:d9:dd:c25:c25:d915:12aa/1282c19:dd:d9:dd:c25:c25:d915:12aa
1722c19:dd:d9:dd:c25:c25:d915:12ab/1282c19:dd:d9:dd:c25:c25:d915:12ab
1732c19:dd:d9:dd:c25:c25:d915:12ac/1282c19:dd:d9:dd:c25:c25:d915:12ac
1742c19:dd:d9:dd:c25:c25:d915:12ad/1282c19:dd:d9:dd:c25:c25:d915:12ad
1752c19:dd:d9:dd:c25:c25:d915:12ae/1282c19:dd:d9:dd:c25:c25:d915:12ae
1762c19:dd:d9:dd:c25:c25:d915:12af/1282c19:dd:d9:dd:c25:c25:d915:12af
1772c19:dd:d9:dd:c25:c25:d915:12b0/1282c19:dd:d9:dd:c25:c25:d915:12b0
1782c19:dd:d9:dd:c25:c25:d915:12b1/1282c19:dd:d9:dd:c25:c25:d915:12b1
1792c19:dd:d9:dd:c25:c25:d915:12b2/1282c19:dd:d9:dd:c25:c25:d915:12b2
1802c19:dd:d9:dd:c25:c25:d915:12b3/1282c19:dd:d9:dd:c25:c25:d915:12b3
1812c19:dd:d9:dd:c25:c25:d915:12b4/1282c19:dd:d9:dd:c25:c25:d915:12b4
1822c19:dd:d9:dd:c25:c25:d915:12b5/1282c19:dd:d9:dd:c25:c25:d915:12b5
1832c19:dd:d9:dd:c25:c25:d915:12b6/1282c19:dd:d9:dd:c25:c25:d915:12b6
1842c19:dd:d9:dd:c25:c25:d915:12b7/1282c19:dd:d9:dd:c25:c25:d915:12b7
1852c19:dd:d9:dd:c25:c25:d915:12b8/1282c19:dd:d9:dd:c25:c25:d915:12b8
1862c19:dd:d9:dd:c25:c25:d915:12b9/1282c19:dd:d9:dd:c25:c25:d915:12b9
1872c19:dd:d9:dd:c25:c25:d915:12ba/1282c19:dd:d9:dd:c25:c25:d915:12ba
1882c19:dd:d9:dd:c25:c25:d915:12bb/1282c19:dd:d9:dd:c25:c25:d915:12bb
1892c19:dd:d9:dd:c25:c25:d915:12bc/1282c19:dd:d9:dd:c25:c25:d915:12bc
1902c19:dd:d9:dd:c25:c25:d915:12bd/1282c19:dd:d9:dd:c25:c25:d915:12bd
1912c19:dd:d9:dd:c25:c25:d915:12be/1282c19:dd:d9:dd:c25:c25:d915:12be
1922c19:dd:d9:dd:c25:c25:d915:12bf/1282c19:dd:d9:dd:c25:c25:d915:12bf
1932c19:dd:d9:dd:c25:c25:d915:12c0/1282c19:dd:d9:dd:c25:c25:d915:12c0
1942c19:dd:d9:dd:c25:c25:d915:12c1/1282c19:dd:d9:dd:c25:c25:d915:12c1
1952c19:dd:d9:dd:c25:c25:d915:12c2/1282c19:dd:d9:dd:c25:c25:d915:12c2
1962c19:dd:d9:dd:c25:c25:d915:12c3/1282c19:dd:d9:dd:c25:c25:d915:12c3
1972c19:dd:d9:dd:c25:c25:d915:12c4/1282c19:dd:d9:dd:c25:c25:d915:12c4
1982c19:dd:d9:dd:c25:c25:d915:12c5/1282c19:dd:d9:dd:c25:c25:d915:12c5
1992c19:dd:d9:dd:c25:c25:d915:12c6/1282c19:dd:d9:dd:c25:c25:d915:12c6
2002c19:dd:d9:dd:c25:c25:d915:12c7/1282c19:dd:d9:dd:c25:c25:d915:12c7
2012c19:dd:d9:dd:c25:c25:d915:12c8/1282c19:dd:d9:dd:c25:c25:d915:12c8
2022c19:dd:d9:dd:c25:c25:d915:12c9/1282c19:dd:d9:dd:c25:c25:d915:12c9
2032c19:dd:d9:dd:c25:c25:d915:12ca/1282c19:dd:d9:dd:c25:c25:d915:12ca
2042c19:dd:d9:dd:c25:c25:d915:12cb/1282c19:dd:d9:dd:c25:c25:d915:12cb
2052c19:dd:d9:dd:c25:c25:d915:12cc/1282c19:dd:d9:dd:c25:c25:d915:12cc
2062c19:dd:d9:dd:c25:c25:d915:12cd/1282c19:dd:d9:dd:c25:c25:d915:12cd
2072c19:dd:d9:dd:c25:c25:d915:12ce/1282c19:dd:d9:dd:c25:c25:d915:12ce
2082c19:dd:d9:dd:c25:c25:d915:12cf/1282c19:dd:d9:dd:c25:c25:d915:12cf
2092c19:dd:d9:dd:c25:c25:d915:12d0/1282c19:dd:d9:dd:c25:c25:d915:12d0
2102c19:dd:d9:dd:c25:c25:d915:12d1/1282c19:dd:d9:dd:c25:c25:d915:12d1
2112c19:dd:d9:dd:c25:c25:d915:12d2/1282c19:dd:d9:dd:c25:c25:d915:12d2
2122c19:dd:d9:dd:c25:c25:d915:12d3/1282c19:dd:d9:dd:c25:c25:d915:12d3
2132c19:dd:d9:dd:c25:c25:d915:12d4/1282c19:dd:d9:dd:c25:c25:d915:12d4
2142c19:dd:d9:dd:c25:c25:d915:12d5/1282c19:dd:d9:dd:c25:c25:d915:12d5
2152c19:dd:d9:dd:c25:c25:d915:12d6/1282c19:dd:d9:dd:c25:c25:d915:12d6
2162c19:dd:d9:dd:c25:c25:d915:12d7/1282c19:dd:d9:dd:c25:c25:d915:12d7
2172c19:dd:d9:dd:c25:c25:d915:12d8/1282c19:dd:d9:dd:c25:c25:d915:12d8
2182c19:dd:d9:dd:c25:c25:d915:12d9/1282c19:dd:d9:dd:c25:c25:d915:12d9
2192c19:dd:d9:dd:c25:c25:d915:12da/1282c19:dd:d9:dd:c25:c25:d915:12da
2202c19:dd:d9:dd:c25:c25:d915:12db/1282c19:dd:d9:dd:c25:c25:d915:12db
2212c19:dd:d9:dd:c25:c25:d915:12dc/1282c19:dd:d9:dd:c25:c25:d915:12dc
2222c19:dd:d9:dd:c25:c25:d915:12dd/1282c19:dd:d9:dd:c25:c25:d915:12dd
2232c19:dd:d9:dd:c25:c25:d915:12de/1282c19:dd:d9:dd:c25:c25:d915:12de
2242c19:dd:d9:dd:c25:c25:d915:12df/1282c19:dd:d9:dd:c25:c25:d915:12df
2252c19:dd:d9:dd:c25:c25:d915:12e0/1282c19:dd:d9:dd:c25:c25:d915:12e0
2262c19:dd:d9:dd:c25:c25:d915:12e1/1282c19:dd:d9:dd:c25:c25:d915:12e1
2272c19:dd:d9:dd:c25:c25:d915:12e2/1282c19:dd:d9:dd:c25:c25:d915:12e2
2282c19:dd:d9:dd:c25:c25:d915:12e3/1282c19:dd:d9:dd:c25:c25:d915:12e3
2292c19:dd:d9:dd:c25:c25:d915:12e4/1282c19:dd:d9:dd:c25:c25:d915:12e4
2302c19:dd:d9:dd:c25:c25:d915:12e5/1282c19:dd:d9:dd:c25:c25:d915:12e5
2312c19:dd:d9:dd:c25:c25:d915:12e6/1282c19:dd:d9:dd:c25:c25:d915:12e6
2322c19:dd:d9:dd:c25:c25:d915:12e7/1282c19:dd:d9:dd:c25:c25:d915:12e7
2332c19:dd:d9:dd:c25:c25:d915:12e8/1282c19:dd:d9:dd:c25:c25:d915:12e8
2342c19:dd:d9:dd:c25:c25:d915:12e9/1282c19:dd:d9:dd:c25:c25:d915:12e9
2352c19:dd:d9:dd:c25:c25:d915:12ea/1282c19:dd:d9:dd:c25:c25:d915:12ea
2362c19:dd:d9:dd:c25:c25:d915:12eb/1282c19:dd:d9:dd:c25:c25:d915:12eb
2372c19:dd:d9:dd:c25:c25:d915:12ec/1282c19:dd:d9:dd:c25:c25:d915:12ec
2382c19:dd:d9:dd:c25:c25:d915:12ed/1282c19:dd:d9:dd:c25:c25:d915:12ed
2392c19:dd:d9:dd:c25:c25:d915:12ee/1282c19:dd:d9:dd:c25:c25:d915:12ee
2402c19:dd:d9:dd:c25:c25:d915:12ef/1282c19:dd:d9:dd:c25:c25:d915:12ef
2412c19:dd:d9:dd:c25:c25:d915:12f0/1282c19:dd:d9:dd:c25:c25:d915:12f0
2422c19:dd:d9:dd:c25:c25:d915:12f1/1282c19:dd:d9:dd:c25:c25:d915:12f1
2432c19:dd:d9:dd:c25:c25:d915:12f2/1282c19:dd:d9:dd:c25:c25:d915:12f2
2442c19:dd:d9:dd:c25:c25:d915:12f3/1282c19:dd:d9:dd:c25:c25:d915:12f3
2452c19:dd:d9:dd:c25:c25:d915:12f4/1282c19:dd:d9:dd:c25:c25:d915:12f4
2462c19:dd:d9:dd:c25:c25:d915:12f5/1282c19:dd:d9:dd:c25:c25:d915:12f5
2472c19:dd:d9:dd:c25:c25:d915:12f6/1282c19:dd:d9:dd:c25:c25:d915:12f6
2482c19:dd:d9:dd:c25:c25:d915:12f7/1282c19:dd:d9:dd:c25:c25:d915:12f7
2492c19:dd:d9:dd:c25:c25:d915:12f8/1282c19:dd:d9:dd:c25:c25:d915:12f8
2502c19:dd:d9:dd:c25:c25:d915:12f9/1282c19:dd:d9:dd:c25:c25:d915:12f9
2512c19:dd:d9:dd:c25:c25:d915:12fa/1282c19:dd:d9:dd:c25:c25:d915:12fa
2522c19:dd:d9:dd:c25:c25:d915:12fb/1282c19:dd:d9:dd:c25:c25:d915:12fb
2532c19:dd:d9:dd:c25:c25:d915:12fc/1282c19:dd:d9:dd:c25:c25:d915:12fc
2542c19:dd:d9:dd:c25:c25:d915:12fd/1282c19:dd:d9:dd:c25:c25:d915:12fd
2552c19:dd:d9:dd:c25:c25:d915:12fe/1282c19:dd:d9:dd:c25:c25:d915:12fe
2562c19:dd:d9:dd:c25:c25:d915:12ff/1282c19:dd:d9:dd:c25:c25:d915:12ff

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.