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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:8100/120
First address
2c19:dd:d9:dd:c25:c25:94de:8100
Last address
2c19:dd:d9:dd:c25:c25:94de:81ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:00d9:00dd:0c25:0c25:94de:8100
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
1.8.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:8100/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:d9:dd:c25:c25:94de:8100/1282c19:dd:d9:dd:c25:c25:94de:8100
22c19:dd:d9:dd:c25:c25:94de:8101/1282c19:dd:d9:dd:c25:c25:94de:8101
32c19:dd:d9:dd:c25:c25:94de:8102/1282c19:dd:d9:dd:c25:c25:94de:8102
42c19:dd:d9:dd:c25:c25:94de:8103/1282c19:dd:d9:dd:c25:c25:94de:8103
52c19:dd:d9:dd:c25:c25:94de:8104/1282c19:dd:d9:dd:c25:c25:94de:8104
62c19:dd:d9:dd:c25:c25:94de:8105/1282c19:dd:d9:dd:c25:c25:94de:8105
72c19:dd:d9:dd:c25:c25:94de:8106/1282c19:dd:d9:dd:c25:c25:94de:8106
82c19:dd:d9:dd:c25:c25:94de:8107/1282c19:dd:d9:dd:c25:c25:94de:8107
92c19:dd:d9:dd:c25:c25:94de:8108/1282c19:dd:d9:dd:c25:c25:94de:8108
102c19:dd:d9:dd:c25:c25:94de:8109/1282c19:dd:d9:dd:c25:c25:94de:8109
112c19:dd:d9:dd:c25:c25:94de:810a/1282c19:dd:d9:dd:c25:c25:94de:810a
122c19:dd:d9:dd:c25:c25:94de:810b/1282c19:dd:d9:dd:c25:c25:94de:810b
132c19:dd:d9:dd:c25:c25:94de:810c/1282c19:dd:d9:dd:c25:c25:94de:810c
142c19:dd:d9:dd:c25:c25:94de:810d/1282c19:dd:d9:dd:c25:c25:94de:810d
152c19:dd:d9:dd:c25:c25:94de:810e/1282c19:dd:d9:dd:c25:c25:94de:810e
162c19:dd:d9:dd:c25:c25:94de:810f/1282c19:dd:d9:dd:c25:c25:94de:810f
172c19:dd:d9:dd:c25:c25:94de:8110/1282c19:dd:d9:dd:c25:c25:94de:8110
182c19:dd:d9:dd:c25:c25:94de:8111/1282c19:dd:d9:dd:c25:c25:94de:8111
192c19:dd:d9:dd:c25:c25:94de:8112/1282c19:dd:d9:dd:c25:c25:94de:8112
202c19:dd:d9:dd:c25:c25:94de:8113/1282c19:dd:d9:dd:c25:c25:94de:8113
212c19:dd:d9:dd:c25:c25:94de:8114/1282c19:dd:d9:dd:c25:c25:94de:8114
222c19:dd:d9:dd:c25:c25:94de:8115/1282c19:dd:d9:dd:c25:c25:94de:8115
232c19:dd:d9:dd:c25:c25:94de:8116/1282c19:dd:d9:dd:c25:c25:94de:8116
242c19:dd:d9:dd:c25:c25:94de:8117/1282c19:dd:d9:dd:c25:c25:94de:8117
252c19:dd:d9:dd:c25:c25:94de:8118/1282c19:dd:d9:dd:c25:c25:94de:8118
262c19:dd:d9:dd:c25:c25:94de:8119/1282c19:dd:d9:dd:c25:c25:94de:8119
272c19:dd:d9:dd:c25:c25:94de:811a/1282c19:dd:d9:dd:c25:c25:94de:811a
282c19:dd:d9:dd:c25:c25:94de:811b/1282c19:dd:d9:dd:c25:c25:94de:811b
292c19:dd:d9:dd:c25:c25:94de:811c/1282c19:dd:d9:dd:c25:c25:94de:811c
302c19:dd:d9:dd:c25:c25:94de:811d/1282c19:dd:d9:dd:c25:c25:94de:811d
312c19:dd:d9:dd:c25:c25:94de:811e/1282c19:dd:d9:dd:c25:c25:94de:811e
322c19:dd:d9:dd:c25:c25:94de:811f/1282c19:dd:d9:dd:c25:c25:94de:811f
332c19:dd:d9:dd:c25:c25:94de:8120/1282c19:dd:d9:dd:c25:c25:94de:8120
342c19:dd:d9:dd:c25:c25:94de:8121/1282c19:dd:d9:dd:c25:c25:94de:8121
352c19:dd:d9:dd:c25:c25:94de:8122/1282c19:dd:d9:dd:c25:c25:94de:8122
362c19:dd:d9:dd:c25:c25:94de:8123/1282c19:dd:d9:dd:c25:c25:94de:8123
372c19:dd:d9:dd:c25:c25:94de:8124/1282c19:dd:d9:dd:c25:c25:94de:8124
382c19:dd:d9:dd:c25:c25:94de:8125/1282c19:dd:d9:dd:c25:c25:94de:8125
392c19:dd:d9:dd:c25:c25:94de:8126/1282c19:dd:d9:dd:c25:c25:94de:8126
402c19:dd:d9:dd:c25:c25:94de:8127/1282c19:dd:d9:dd:c25:c25:94de:8127
412c19:dd:d9:dd:c25:c25:94de:8128/1282c19:dd:d9:dd:c25:c25:94de:8128
422c19:dd:d9:dd:c25:c25:94de:8129/1282c19:dd:d9:dd:c25:c25:94de:8129
432c19:dd:d9:dd:c25:c25:94de:812a/1282c19:dd:d9:dd:c25:c25:94de:812a
442c19:dd:d9:dd:c25:c25:94de:812b/1282c19:dd:d9:dd:c25:c25:94de:812b
452c19:dd:d9:dd:c25:c25:94de:812c/1282c19:dd:d9:dd:c25:c25:94de:812c
462c19:dd:d9:dd:c25:c25:94de:812d/1282c19:dd:d9:dd:c25:c25:94de:812d
472c19:dd:d9:dd:c25:c25:94de:812e/1282c19:dd:d9:dd:c25:c25:94de:812e
482c19:dd:d9:dd:c25:c25:94de:812f/1282c19:dd:d9:dd:c25:c25:94de:812f
492c19:dd:d9:dd:c25:c25:94de:8130/1282c19:dd:d9:dd:c25:c25:94de:8130
502c19:dd:d9:dd:c25:c25:94de:8131/1282c19:dd:d9:dd:c25:c25:94de:8131
512c19:dd:d9:dd:c25:c25:94de:8132/1282c19:dd:d9:dd:c25:c25:94de:8132
522c19:dd:d9:dd:c25:c25:94de:8133/1282c19:dd:d9:dd:c25:c25:94de:8133
532c19:dd:d9:dd:c25:c25:94de:8134/1282c19:dd:d9:dd:c25:c25:94de:8134
542c19:dd:d9:dd:c25:c25:94de:8135/1282c19:dd:d9:dd:c25:c25:94de:8135
552c19:dd:d9:dd:c25:c25:94de:8136/1282c19:dd:d9:dd:c25:c25:94de:8136
562c19:dd:d9:dd:c25:c25:94de:8137/1282c19:dd:d9:dd:c25:c25:94de:8137
572c19:dd:d9:dd:c25:c25:94de:8138/1282c19:dd:d9:dd:c25:c25:94de:8138
582c19:dd:d9:dd:c25:c25:94de:8139/1282c19:dd:d9:dd:c25:c25:94de:8139
592c19:dd:d9:dd:c25:c25:94de:813a/1282c19:dd:d9:dd:c25:c25:94de:813a
602c19:dd:d9:dd:c25:c25:94de:813b/1282c19:dd:d9:dd:c25:c25:94de:813b
612c19:dd:d9:dd:c25:c25:94de:813c/1282c19:dd:d9:dd:c25:c25:94de:813c
622c19:dd:d9:dd:c25:c25:94de:813d/1282c19:dd:d9:dd:c25:c25:94de:813d
632c19:dd:d9:dd:c25:c25:94de:813e/1282c19:dd:d9:dd:c25:c25:94de:813e
642c19:dd:d9:dd:c25:c25:94de:813f/1282c19:dd:d9:dd:c25:c25:94de:813f
652c19:dd:d9:dd:c25:c25:94de:8140/1282c19:dd:d9:dd:c25:c25:94de:8140
662c19:dd:d9:dd:c25:c25:94de:8141/1282c19:dd:d9:dd:c25:c25:94de:8141
672c19:dd:d9:dd:c25:c25:94de:8142/1282c19:dd:d9:dd:c25:c25:94de:8142
682c19:dd:d9:dd:c25:c25:94de:8143/1282c19:dd:d9:dd:c25:c25:94de:8143
692c19:dd:d9:dd:c25:c25:94de:8144/1282c19:dd:d9:dd:c25:c25:94de:8144
702c19:dd:d9:dd:c25:c25:94de:8145/1282c19:dd:d9:dd:c25:c25:94de:8145
712c19:dd:d9:dd:c25:c25:94de:8146/1282c19:dd:d9:dd:c25:c25:94de:8146
722c19:dd:d9:dd:c25:c25:94de:8147/1282c19:dd:d9:dd:c25:c25:94de:8147
732c19:dd:d9:dd:c25:c25:94de:8148/1282c19:dd:d9:dd:c25:c25:94de:8148
742c19:dd:d9:dd:c25:c25:94de:8149/1282c19:dd:d9:dd:c25:c25:94de:8149
752c19:dd:d9:dd:c25:c25:94de:814a/1282c19:dd:d9:dd:c25:c25:94de:814a
762c19:dd:d9:dd:c25:c25:94de:814b/1282c19:dd:d9:dd:c25:c25:94de:814b
772c19:dd:d9:dd:c25:c25:94de:814c/1282c19:dd:d9:dd:c25:c25:94de:814c
782c19:dd:d9:dd:c25:c25:94de:814d/1282c19:dd:d9:dd:c25:c25:94de:814d
792c19:dd:d9:dd:c25:c25:94de:814e/1282c19:dd:d9:dd:c25:c25:94de:814e
802c19:dd:d9:dd:c25:c25:94de:814f/1282c19:dd:d9:dd:c25:c25:94de:814f
812c19:dd:d9:dd:c25:c25:94de:8150/1282c19:dd:d9:dd:c25:c25:94de:8150
822c19:dd:d9:dd:c25:c25:94de:8151/1282c19:dd:d9:dd:c25:c25:94de:8151
832c19:dd:d9:dd:c25:c25:94de:8152/1282c19:dd:d9:dd:c25:c25:94de:8152
842c19:dd:d9:dd:c25:c25:94de:8153/1282c19:dd:d9:dd:c25:c25:94de:8153
852c19:dd:d9:dd:c25:c25:94de:8154/1282c19:dd:d9:dd:c25:c25:94de:8154
862c19:dd:d9:dd:c25:c25:94de:8155/1282c19:dd:d9:dd:c25:c25:94de:8155
872c19:dd:d9:dd:c25:c25:94de:8156/1282c19:dd:d9:dd:c25:c25:94de:8156
882c19:dd:d9:dd:c25:c25:94de:8157/1282c19:dd:d9:dd:c25:c25:94de:8157
892c19:dd:d9:dd:c25:c25:94de:8158/1282c19:dd:d9:dd:c25:c25:94de:8158
902c19:dd:d9:dd:c25:c25:94de:8159/1282c19:dd:d9:dd:c25:c25:94de:8159
912c19:dd:d9:dd:c25:c25:94de:815a/1282c19:dd:d9:dd:c25:c25:94de:815a
922c19:dd:d9:dd:c25:c25:94de:815b/1282c19:dd:d9:dd:c25:c25:94de:815b
932c19:dd:d9:dd:c25:c25:94de:815c/1282c19:dd:d9:dd:c25:c25:94de:815c
942c19:dd:d9:dd:c25:c25:94de:815d/1282c19:dd:d9:dd:c25:c25:94de:815d
952c19:dd:d9:dd:c25:c25:94de:815e/1282c19:dd:d9:dd:c25:c25:94de:815e
962c19:dd:d9:dd:c25:c25:94de:815f/1282c19:dd:d9:dd:c25:c25:94de:815f
972c19:dd:d9:dd:c25:c25:94de:8160/1282c19:dd:d9:dd:c25:c25:94de:8160
982c19:dd:d9:dd:c25:c25:94de:8161/1282c19:dd:d9:dd:c25:c25:94de:8161
992c19:dd:d9:dd:c25:c25:94de:8162/1282c19:dd:d9:dd:c25:c25:94de:8162
1002c19:dd:d9:dd:c25:c25:94de:8163/1282c19:dd:d9:dd:c25:c25:94de:8163
1012c19:dd:d9:dd:c25:c25:94de:8164/1282c19:dd:d9:dd:c25:c25:94de:8164
1022c19:dd:d9:dd:c25:c25:94de:8165/1282c19:dd:d9:dd:c25:c25:94de:8165
1032c19:dd:d9:dd:c25:c25:94de:8166/1282c19:dd:d9:dd:c25:c25:94de:8166
1042c19:dd:d9:dd:c25:c25:94de:8167/1282c19:dd:d9:dd:c25:c25:94de:8167
1052c19:dd:d9:dd:c25:c25:94de:8168/1282c19:dd:d9:dd:c25:c25:94de:8168
1062c19:dd:d9:dd:c25:c25:94de:8169/1282c19:dd:d9:dd:c25:c25:94de:8169
1072c19:dd:d9:dd:c25:c25:94de:816a/1282c19:dd:d9:dd:c25:c25:94de:816a
1082c19:dd:d9:dd:c25:c25:94de:816b/1282c19:dd:d9:dd:c25:c25:94de:816b
1092c19:dd:d9:dd:c25:c25:94de:816c/1282c19:dd:d9:dd:c25:c25:94de:816c
1102c19:dd:d9:dd:c25:c25:94de:816d/1282c19:dd:d9:dd:c25:c25:94de:816d
1112c19:dd:d9:dd:c25:c25:94de:816e/1282c19:dd:d9:dd:c25:c25:94de:816e
1122c19:dd:d9:dd:c25:c25:94de:816f/1282c19:dd:d9:dd:c25:c25:94de:816f
1132c19:dd:d9:dd:c25:c25:94de:8170/1282c19:dd:d9:dd:c25:c25:94de:8170
1142c19:dd:d9:dd:c25:c25:94de:8171/1282c19:dd:d9:dd:c25:c25:94de:8171
1152c19:dd:d9:dd:c25:c25:94de:8172/1282c19:dd:d9:dd:c25:c25:94de:8172
1162c19:dd:d9:dd:c25:c25:94de:8173/1282c19:dd:d9:dd:c25:c25:94de:8173
1172c19:dd:d9:dd:c25:c25:94de:8174/1282c19:dd:d9:dd:c25:c25:94de:8174
1182c19:dd:d9:dd:c25:c25:94de:8175/1282c19:dd:d9:dd:c25:c25:94de:8175
1192c19:dd:d9:dd:c25:c25:94de:8176/1282c19:dd:d9:dd:c25:c25:94de:8176
1202c19:dd:d9:dd:c25:c25:94de:8177/1282c19:dd:d9:dd:c25:c25:94de:8177
1212c19:dd:d9:dd:c25:c25:94de:8178/1282c19:dd:d9:dd:c25:c25:94de:8178
1222c19:dd:d9:dd:c25:c25:94de:8179/1282c19:dd:d9:dd:c25:c25:94de:8179
1232c19:dd:d9:dd:c25:c25:94de:817a/1282c19:dd:d9:dd:c25:c25:94de:817a
1242c19:dd:d9:dd:c25:c25:94de:817b/1282c19:dd:d9:dd:c25:c25:94de:817b
1252c19:dd:d9:dd:c25:c25:94de:817c/1282c19:dd:d9:dd:c25:c25:94de:817c
1262c19:dd:d9:dd:c25:c25:94de:817d/1282c19:dd:d9:dd:c25:c25:94de:817d
1272c19:dd:d9:dd:c25:c25:94de:817e/1282c19:dd:d9:dd:c25:c25:94de:817e
1282c19:dd:d9:dd:c25:c25:94de:817f/1282c19:dd:d9:dd:c25:c25:94de:817f
1292c19:dd:d9:dd:c25:c25:94de:8180/1282c19:dd:d9:dd:c25:c25:94de:8180
1302c19:dd:d9:dd:c25:c25:94de:8181/1282c19:dd:d9:dd:c25:c25:94de:8181
1312c19:dd:d9:dd:c25:c25:94de:8182/1282c19:dd:d9:dd:c25:c25:94de:8182
1322c19:dd:d9:dd:c25:c25:94de:8183/1282c19:dd:d9:dd:c25:c25:94de:8183
1332c19:dd:d9:dd:c25:c25:94de:8184/1282c19:dd:d9:dd:c25:c25:94de:8184
1342c19:dd:d9:dd:c25:c25:94de:8185/1282c19:dd:d9:dd:c25:c25:94de:8185
1352c19:dd:d9:dd:c25:c25:94de:8186/1282c19:dd:d9:dd:c25:c25:94de:8186
1362c19:dd:d9:dd:c25:c25:94de:8187/1282c19:dd:d9:dd:c25:c25:94de:8187
1372c19:dd:d9:dd:c25:c25:94de:8188/1282c19:dd:d9:dd:c25:c25:94de:8188
1382c19:dd:d9:dd:c25:c25:94de:8189/1282c19:dd:d9:dd:c25:c25:94de:8189
1392c19:dd:d9:dd:c25:c25:94de:818a/1282c19:dd:d9:dd:c25:c25:94de:818a
1402c19:dd:d9:dd:c25:c25:94de:818b/1282c19:dd:d9:dd:c25:c25:94de:818b
1412c19:dd:d9:dd:c25:c25:94de:818c/1282c19:dd:d9:dd:c25:c25:94de:818c
1422c19:dd:d9:dd:c25:c25:94de:818d/1282c19:dd:d9:dd:c25:c25:94de:818d
1432c19:dd:d9:dd:c25:c25:94de:818e/1282c19:dd:d9:dd:c25:c25:94de:818e
1442c19:dd:d9:dd:c25:c25:94de:818f/1282c19:dd:d9:dd:c25:c25:94de:818f
1452c19:dd:d9:dd:c25:c25:94de:8190/1282c19:dd:d9:dd:c25:c25:94de:8190
1462c19:dd:d9:dd:c25:c25:94de:8191/1282c19:dd:d9:dd:c25:c25:94de:8191
1472c19:dd:d9:dd:c25:c25:94de:8192/1282c19:dd:d9:dd:c25:c25:94de:8192
1482c19:dd:d9:dd:c25:c25:94de:8193/1282c19:dd:d9:dd:c25:c25:94de:8193
1492c19:dd:d9:dd:c25:c25:94de:8194/1282c19:dd:d9:dd:c25:c25:94de:8194
1502c19:dd:d9:dd:c25:c25:94de:8195/1282c19:dd:d9:dd:c25:c25:94de:8195
1512c19:dd:d9:dd:c25:c25:94de:8196/1282c19:dd:d9:dd:c25:c25:94de:8196
1522c19:dd:d9:dd:c25:c25:94de:8197/1282c19:dd:d9:dd:c25:c25:94de:8197
1532c19:dd:d9:dd:c25:c25:94de:8198/1282c19:dd:d9:dd:c25:c25:94de:8198
1542c19:dd:d9:dd:c25:c25:94de:8199/1282c19:dd:d9:dd:c25:c25:94de:8199
1552c19:dd:d9:dd:c25:c25:94de:819a/1282c19:dd:d9:dd:c25:c25:94de:819a
1562c19:dd:d9:dd:c25:c25:94de:819b/1282c19:dd:d9:dd:c25:c25:94de:819b
1572c19:dd:d9:dd:c25:c25:94de:819c/1282c19:dd:d9:dd:c25:c25:94de:819c
1582c19:dd:d9:dd:c25:c25:94de:819d/1282c19:dd:d9:dd:c25:c25:94de:819d
1592c19:dd:d9:dd:c25:c25:94de:819e/1282c19:dd:d9:dd:c25:c25:94de:819e
1602c19:dd:d9:dd:c25:c25:94de:819f/1282c19:dd:d9:dd:c25:c25:94de:819f
1612c19:dd:d9:dd:c25:c25:94de:81a0/1282c19:dd:d9:dd:c25:c25:94de:81a0
1622c19:dd:d9:dd:c25:c25:94de:81a1/1282c19:dd:d9:dd:c25:c25:94de:81a1
1632c19:dd:d9:dd:c25:c25:94de:81a2/1282c19:dd:d9:dd:c25:c25:94de:81a2
1642c19:dd:d9:dd:c25:c25:94de:81a3/1282c19:dd:d9:dd:c25:c25:94de:81a3
1652c19:dd:d9:dd:c25:c25:94de:81a4/1282c19:dd:d9:dd:c25:c25:94de:81a4
1662c19:dd:d9:dd:c25:c25:94de:81a5/1282c19:dd:d9:dd:c25:c25:94de:81a5
1672c19:dd:d9:dd:c25:c25:94de:81a6/1282c19:dd:d9:dd:c25:c25:94de:81a6
1682c19:dd:d9:dd:c25:c25:94de:81a7/1282c19:dd:d9:dd:c25:c25:94de:81a7
1692c19:dd:d9:dd:c25:c25:94de:81a8/1282c19:dd:d9:dd:c25:c25:94de:81a8
1702c19:dd:d9:dd:c25:c25:94de:81a9/1282c19:dd:d9:dd:c25:c25:94de:81a9
1712c19:dd:d9:dd:c25:c25:94de:81aa/1282c19:dd:d9:dd:c25:c25:94de:81aa
1722c19:dd:d9:dd:c25:c25:94de:81ab/1282c19:dd:d9:dd:c25:c25:94de:81ab
1732c19:dd:d9:dd:c25:c25:94de:81ac/1282c19:dd:d9:dd:c25:c25:94de:81ac
1742c19:dd:d9:dd:c25:c25:94de:81ad/1282c19:dd:d9:dd:c25:c25:94de:81ad
1752c19:dd:d9:dd:c25:c25:94de:81ae/1282c19:dd:d9:dd:c25:c25:94de:81ae
1762c19:dd:d9:dd:c25:c25:94de:81af/1282c19:dd:d9:dd:c25:c25:94de:81af
1772c19:dd:d9:dd:c25:c25:94de:81b0/1282c19:dd:d9:dd:c25:c25:94de:81b0
1782c19:dd:d9:dd:c25:c25:94de:81b1/1282c19:dd:d9:dd:c25:c25:94de:81b1
1792c19:dd:d9:dd:c25:c25:94de:81b2/1282c19:dd:d9:dd:c25:c25:94de:81b2
1802c19:dd:d9:dd:c25:c25:94de:81b3/1282c19:dd:d9:dd:c25:c25:94de:81b3
1812c19:dd:d9:dd:c25:c25:94de:81b4/1282c19:dd:d9:dd:c25:c25:94de:81b4
1822c19:dd:d9:dd:c25:c25:94de:81b5/1282c19:dd:d9:dd:c25:c25:94de:81b5
1832c19:dd:d9:dd:c25:c25:94de:81b6/1282c19:dd:d9:dd:c25:c25:94de:81b6
1842c19:dd:d9:dd:c25:c25:94de:81b7/1282c19:dd:d9:dd:c25:c25:94de:81b7
1852c19:dd:d9:dd:c25:c25:94de:81b8/1282c19:dd:d9:dd:c25:c25:94de:81b8
1862c19:dd:d9:dd:c25:c25:94de:81b9/1282c19:dd:d9:dd:c25:c25:94de:81b9
1872c19:dd:d9:dd:c25:c25:94de:81ba/1282c19:dd:d9:dd:c25:c25:94de:81ba
1882c19:dd:d9:dd:c25:c25:94de:81bb/1282c19:dd:d9:dd:c25:c25:94de:81bb
1892c19:dd:d9:dd:c25:c25:94de:81bc/1282c19:dd:d9:dd:c25:c25:94de:81bc
1902c19:dd:d9:dd:c25:c25:94de:81bd/1282c19:dd:d9:dd:c25:c25:94de:81bd
1912c19:dd:d9:dd:c25:c25:94de:81be/1282c19:dd:d9:dd:c25:c25:94de:81be
1922c19:dd:d9:dd:c25:c25:94de:81bf/1282c19:dd:d9:dd:c25:c25:94de:81bf
1932c19:dd:d9:dd:c25:c25:94de:81c0/1282c19:dd:d9:dd:c25:c25:94de:81c0
1942c19:dd:d9:dd:c25:c25:94de:81c1/1282c19:dd:d9:dd:c25:c25:94de:81c1
1952c19:dd:d9:dd:c25:c25:94de:81c2/1282c19:dd:d9:dd:c25:c25:94de:81c2
1962c19:dd:d9:dd:c25:c25:94de:81c3/1282c19:dd:d9:dd:c25:c25:94de:81c3
1972c19:dd:d9:dd:c25:c25:94de:81c4/1282c19:dd:d9:dd:c25:c25:94de:81c4
1982c19:dd:d9:dd:c25:c25:94de:81c5/1282c19:dd:d9:dd:c25:c25:94de:81c5
1992c19:dd:d9:dd:c25:c25:94de:81c6/1282c19:dd:d9:dd:c25:c25:94de:81c6
2002c19:dd:d9:dd:c25:c25:94de:81c7/1282c19:dd:d9:dd:c25:c25:94de:81c7
2012c19:dd:d9:dd:c25:c25:94de:81c8/1282c19:dd:d9:dd:c25:c25:94de:81c8
2022c19:dd:d9:dd:c25:c25:94de:81c9/1282c19:dd:d9:dd:c25:c25:94de:81c9
2032c19:dd:d9:dd:c25:c25:94de:81ca/1282c19:dd:d9:dd:c25:c25:94de:81ca
2042c19:dd:d9:dd:c25:c25:94de:81cb/1282c19:dd:d9:dd:c25:c25:94de:81cb
2052c19:dd:d9:dd:c25:c25:94de:81cc/1282c19:dd:d9:dd:c25:c25:94de:81cc
2062c19:dd:d9:dd:c25:c25:94de:81cd/1282c19:dd:d9:dd:c25:c25:94de:81cd
2072c19:dd:d9:dd:c25:c25:94de:81ce/1282c19:dd:d9:dd:c25:c25:94de:81ce
2082c19:dd:d9:dd:c25:c25:94de:81cf/1282c19:dd:d9:dd:c25:c25:94de:81cf
2092c19:dd:d9:dd:c25:c25:94de:81d0/1282c19:dd:d9:dd:c25:c25:94de:81d0
2102c19:dd:d9:dd:c25:c25:94de:81d1/1282c19:dd:d9:dd:c25:c25:94de:81d1
2112c19:dd:d9:dd:c25:c25:94de:81d2/1282c19:dd:d9:dd:c25:c25:94de:81d2
2122c19:dd:d9:dd:c25:c25:94de:81d3/1282c19:dd:d9:dd:c25:c25:94de:81d3
2132c19:dd:d9:dd:c25:c25:94de:81d4/1282c19:dd:d9:dd:c25:c25:94de:81d4
2142c19:dd:d9:dd:c25:c25:94de:81d5/1282c19:dd:d9:dd:c25:c25:94de:81d5
2152c19:dd:d9:dd:c25:c25:94de:81d6/1282c19:dd:d9:dd:c25:c25:94de:81d6
2162c19:dd:d9:dd:c25:c25:94de:81d7/1282c19:dd:d9:dd:c25:c25:94de:81d7
2172c19:dd:d9:dd:c25:c25:94de:81d8/1282c19:dd:d9:dd:c25:c25:94de:81d8
2182c19:dd:d9:dd:c25:c25:94de:81d9/1282c19:dd:d9:dd:c25:c25:94de:81d9
2192c19:dd:d9:dd:c25:c25:94de:81da/1282c19:dd:d9:dd:c25:c25:94de:81da
2202c19:dd:d9:dd:c25:c25:94de:81db/1282c19:dd:d9:dd:c25:c25:94de:81db
2212c19:dd:d9:dd:c25:c25:94de:81dc/1282c19:dd:d9:dd:c25:c25:94de:81dc
2222c19:dd:d9:dd:c25:c25:94de:81dd/1282c19:dd:d9:dd:c25:c25:94de:81dd
2232c19:dd:d9:dd:c25:c25:94de:81de/1282c19:dd:d9:dd:c25:c25:94de:81de
2242c19:dd:d9:dd:c25:c25:94de:81df/1282c19:dd:d9:dd:c25:c25:94de:81df
2252c19:dd:d9:dd:c25:c25:94de:81e0/1282c19:dd:d9:dd:c25:c25:94de:81e0
2262c19:dd:d9:dd:c25:c25:94de:81e1/1282c19:dd:d9:dd:c25:c25:94de:81e1
2272c19:dd:d9:dd:c25:c25:94de:81e2/1282c19:dd:d9:dd:c25:c25:94de:81e2
2282c19:dd:d9:dd:c25:c25:94de:81e3/1282c19:dd:d9:dd:c25:c25:94de:81e3
2292c19:dd:d9:dd:c25:c25:94de:81e4/1282c19:dd:d9:dd:c25:c25:94de:81e4
2302c19:dd:d9:dd:c25:c25:94de:81e5/1282c19:dd:d9:dd:c25:c25:94de:81e5
2312c19:dd:d9:dd:c25:c25:94de:81e6/1282c19:dd:d9:dd:c25:c25:94de:81e6
2322c19:dd:d9:dd:c25:c25:94de:81e7/1282c19:dd:d9:dd:c25:c25:94de:81e7
2332c19:dd:d9:dd:c25:c25:94de:81e8/1282c19:dd:d9:dd:c25:c25:94de:81e8
2342c19:dd:d9:dd:c25:c25:94de:81e9/1282c19:dd:d9:dd:c25:c25:94de:81e9
2352c19:dd:d9:dd:c25:c25:94de:81ea/1282c19:dd:d9:dd:c25:c25:94de:81ea
2362c19:dd:d9:dd:c25:c25:94de:81eb/1282c19:dd:d9:dd:c25:c25:94de:81eb
2372c19:dd:d9:dd:c25:c25:94de:81ec/1282c19:dd:d9:dd:c25:c25:94de:81ec
2382c19:dd:d9:dd:c25:c25:94de:81ed/1282c19:dd:d9:dd:c25:c25:94de:81ed
2392c19:dd:d9:dd:c25:c25:94de:81ee/1282c19:dd:d9:dd:c25:c25:94de:81ee
2402c19:dd:d9:dd:c25:c25:94de:81ef/1282c19:dd:d9:dd:c25:c25:94de:81ef
2412c19:dd:d9:dd:c25:c25:94de:81f0/1282c19:dd:d9:dd:c25:c25:94de:81f0
2422c19:dd:d9:dd:c25:c25:94de:81f1/1282c19:dd:d9:dd:c25:c25:94de:81f1
2432c19:dd:d9:dd:c25:c25:94de:81f2/1282c19:dd:d9:dd:c25:c25:94de:81f2
2442c19:dd:d9:dd:c25:c25:94de:81f3/1282c19:dd:d9:dd:c25:c25:94de:81f3
2452c19:dd:d9:dd:c25:c25:94de:81f4/1282c19:dd:d9:dd:c25:c25:94de:81f4
2462c19:dd:d9:dd:c25:c25:94de:81f5/1282c19:dd:d9:dd:c25:c25:94de:81f5
2472c19:dd:d9:dd:c25:c25:94de:81f6/1282c19:dd:d9:dd:c25:c25:94de:81f6
2482c19:dd:d9:dd:c25:c25:94de:81f7/1282c19:dd:d9:dd:c25:c25:94de:81f7
2492c19:dd:d9:dd:c25:c25:94de:81f8/1282c19:dd:d9:dd:c25:c25:94de:81f8
2502c19:dd:d9:dd:c25:c25:94de:81f9/1282c19:dd:d9:dd:c25:c25:94de:81f9
2512c19:dd:d9:dd:c25:c25:94de:81fa/1282c19:dd:d9:dd:c25:c25:94de:81fa
2522c19:dd:d9:dd:c25:c25:94de:81fb/1282c19:dd:d9:dd:c25:c25:94de:81fb
2532c19:dd:d9:dd:c25:c25:94de:81fc/1282c19:dd:d9:dd:c25:c25:94de:81fc
2542c19:dd:d9:dd:c25:c25:94de:81fd/1282c19:dd:d9:dd:c25:c25:94de:81fd
2552c19:dd:d9:dd:c25:c25:94de:81fe/1282c19:dd:d9:dd:c25:c25:94de:81fe
2562c19:dd:d9:dd:c25:c25:94de:81ff/1282c19:dd:d9:dd:c25:c25:94de:81ff

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.