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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:3100/120
First address
2c19:dd:d9:dd:c25:c25:94de:3100
Last address
2c19:dd:d9:dd:c25:c25:94de:31ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:00d9:00dd:0c25:0c25:94de:3100
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
1.3.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:3100/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:d9:dd:c25:c25:94de:3100/1282c19:dd:d9:dd:c25:c25:94de:3100
22c19:dd:d9:dd:c25:c25:94de:3101/1282c19:dd:d9:dd:c25:c25:94de:3101
32c19:dd:d9:dd:c25:c25:94de:3102/1282c19:dd:d9:dd:c25:c25:94de:3102
42c19:dd:d9:dd:c25:c25:94de:3103/1282c19:dd:d9:dd:c25:c25:94de:3103
52c19:dd:d9:dd:c25:c25:94de:3104/1282c19:dd:d9:dd:c25:c25:94de:3104
62c19:dd:d9:dd:c25:c25:94de:3105/1282c19:dd:d9:dd:c25:c25:94de:3105
72c19:dd:d9:dd:c25:c25:94de:3106/1282c19:dd:d9:dd:c25:c25:94de:3106
82c19:dd:d9:dd:c25:c25:94de:3107/1282c19:dd:d9:dd:c25:c25:94de:3107
92c19:dd:d9:dd:c25:c25:94de:3108/1282c19:dd:d9:dd:c25:c25:94de:3108
102c19:dd:d9:dd:c25:c25:94de:3109/1282c19:dd:d9:dd:c25:c25:94de:3109
112c19:dd:d9:dd:c25:c25:94de:310a/1282c19:dd:d9:dd:c25:c25:94de:310a
122c19:dd:d9:dd:c25:c25:94de:310b/1282c19:dd:d9:dd:c25:c25:94de:310b
132c19:dd:d9:dd:c25:c25:94de:310c/1282c19:dd:d9:dd:c25:c25:94de:310c
142c19:dd:d9:dd:c25:c25:94de:310d/1282c19:dd:d9:dd:c25:c25:94de:310d
152c19:dd:d9:dd:c25:c25:94de:310e/1282c19:dd:d9:dd:c25:c25:94de:310e
162c19:dd:d9:dd:c25:c25:94de:310f/1282c19:dd:d9:dd:c25:c25:94de:310f
172c19:dd:d9:dd:c25:c25:94de:3110/1282c19:dd:d9:dd:c25:c25:94de:3110
182c19:dd:d9:dd:c25:c25:94de:3111/1282c19:dd:d9:dd:c25:c25:94de:3111
192c19:dd:d9:dd:c25:c25:94de:3112/1282c19:dd:d9:dd:c25:c25:94de:3112
202c19:dd:d9:dd:c25:c25:94de:3113/1282c19:dd:d9:dd:c25:c25:94de:3113
212c19:dd:d9:dd:c25:c25:94de:3114/1282c19:dd:d9:dd:c25:c25:94de:3114
222c19:dd:d9:dd:c25:c25:94de:3115/1282c19:dd:d9:dd:c25:c25:94de:3115
232c19:dd:d9:dd:c25:c25:94de:3116/1282c19:dd:d9:dd:c25:c25:94de:3116
242c19:dd:d9:dd:c25:c25:94de:3117/1282c19:dd:d9:dd:c25:c25:94de:3117
252c19:dd:d9:dd:c25:c25:94de:3118/1282c19:dd:d9:dd:c25:c25:94de:3118
262c19:dd:d9:dd:c25:c25:94de:3119/1282c19:dd:d9:dd:c25:c25:94de:3119
272c19:dd:d9:dd:c25:c25:94de:311a/1282c19:dd:d9:dd:c25:c25:94de:311a
282c19:dd:d9:dd:c25:c25:94de:311b/1282c19:dd:d9:dd:c25:c25:94de:311b
292c19:dd:d9:dd:c25:c25:94de:311c/1282c19:dd:d9:dd:c25:c25:94de:311c
302c19:dd:d9:dd:c25:c25:94de:311d/1282c19:dd:d9:dd:c25:c25:94de:311d
312c19:dd:d9:dd:c25:c25:94de:311e/1282c19:dd:d9:dd:c25:c25:94de:311e
322c19:dd:d9:dd:c25:c25:94de:311f/1282c19:dd:d9:dd:c25:c25:94de:311f
332c19:dd:d9:dd:c25:c25:94de:3120/1282c19:dd:d9:dd:c25:c25:94de:3120
342c19:dd:d9:dd:c25:c25:94de:3121/1282c19:dd:d9:dd:c25:c25:94de:3121
352c19:dd:d9:dd:c25:c25:94de:3122/1282c19:dd:d9:dd:c25:c25:94de:3122
362c19:dd:d9:dd:c25:c25:94de:3123/1282c19:dd:d9:dd:c25:c25:94de:3123
372c19:dd:d9:dd:c25:c25:94de:3124/1282c19:dd:d9:dd:c25:c25:94de:3124
382c19:dd:d9:dd:c25:c25:94de:3125/1282c19:dd:d9:dd:c25:c25:94de:3125
392c19:dd:d9:dd:c25:c25:94de:3126/1282c19:dd:d9:dd:c25:c25:94de:3126
402c19:dd:d9:dd:c25:c25:94de:3127/1282c19:dd:d9:dd:c25:c25:94de:3127
412c19:dd:d9:dd:c25:c25:94de:3128/1282c19:dd:d9:dd:c25:c25:94de:3128
422c19:dd:d9:dd:c25:c25:94de:3129/1282c19:dd:d9:dd:c25:c25:94de:3129
432c19:dd:d9:dd:c25:c25:94de:312a/1282c19:dd:d9:dd:c25:c25:94de:312a
442c19:dd:d9:dd:c25:c25:94de:312b/1282c19:dd:d9:dd:c25:c25:94de:312b
452c19:dd:d9:dd:c25:c25:94de:312c/1282c19:dd:d9:dd:c25:c25:94de:312c
462c19:dd:d9:dd:c25:c25:94de:312d/1282c19:dd:d9:dd:c25:c25:94de:312d
472c19:dd:d9:dd:c25:c25:94de:312e/1282c19:dd:d9:dd:c25:c25:94de:312e
482c19:dd:d9:dd:c25:c25:94de:312f/1282c19:dd:d9:dd:c25:c25:94de:312f
492c19:dd:d9:dd:c25:c25:94de:3130/1282c19:dd:d9:dd:c25:c25:94de:3130
502c19:dd:d9:dd:c25:c25:94de:3131/1282c19:dd:d9:dd:c25:c25:94de:3131
512c19:dd:d9:dd:c25:c25:94de:3132/1282c19:dd:d9:dd:c25:c25:94de:3132
522c19:dd:d9:dd:c25:c25:94de:3133/1282c19:dd:d9:dd:c25:c25:94de:3133
532c19:dd:d9:dd:c25:c25:94de:3134/1282c19:dd:d9:dd:c25:c25:94de:3134
542c19:dd:d9:dd:c25:c25:94de:3135/1282c19:dd:d9:dd:c25:c25:94de:3135
552c19:dd:d9:dd:c25:c25:94de:3136/1282c19:dd:d9:dd:c25:c25:94de:3136
562c19:dd:d9:dd:c25:c25:94de:3137/1282c19:dd:d9:dd:c25:c25:94de:3137
572c19:dd:d9:dd:c25:c25:94de:3138/1282c19:dd:d9:dd:c25:c25:94de:3138
582c19:dd:d9:dd:c25:c25:94de:3139/1282c19:dd:d9:dd:c25:c25:94de:3139
592c19:dd:d9:dd:c25:c25:94de:313a/1282c19:dd:d9:dd:c25:c25:94de:313a
602c19:dd:d9:dd:c25:c25:94de:313b/1282c19:dd:d9:dd:c25:c25:94de:313b
612c19:dd:d9:dd:c25:c25:94de:313c/1282c19:dd:d9:dd:c25:c25:94de:313c
622c19:dd:d9:dd:c25:c25:94de:313d/1282c19:dd:d9:dd:c25:c25:94de:313d
632c19:dd:d9:dd:c25:c25:94de:313e/1282c19:dd:d9:dd:c25:c25:94de:313e
642c19:dd:d9:dd:c25:c25:94de:313f/1282c19:dd:d9:dd:c25:c25:94de:313f
652c19:dd:d9:dd:c25:c25:94de:3140/1282c19:dd:d9:dd:c25:c25:94de:3140
662c19:dd:d9:dd:c25:c25:94de:3141/1282c19:dd:d9:dd:c25:c25:94de:3141
672c19:dd:d9:dd:c25:c25:94de:3142/1282c19:dd:d9:dd:c25:c25:94de:3142
682c19:dd:d9:dd:c25:c25:94de:3143/1282c19:dd:d9:dd:c25:c25:94de:3143
692c19:dd:d9:dd:c25:c25:94de:3144/1282c19:dd:d9:dd:c25:c25:94de:3144
702c19:dd:d9:dd:c25:c25:94de:3145/1282c19:dd:d9:dd:c25:c25:94de:3145
712c19:dd:d9:dd:c25:c25:94de:3146/1282c19:dd:d9:dd:c25:c25:94de:3146
722c19:dd:d9:dd:c25:c25:94de:3147/1282c19:dd:d9:dd:c25:c25:94de:3147
732c19:dd:d9:dd:c25:c25:94de:3148/1282c19:dd:d9:dd:c25:c25:94de:3148
742c19:dd:d9:dd:c25:c25:94de:3149/1282c19:dd:d9:dd:c25:c25:94de:3149
752c19:dd:d9:dd:c25:c25:94de:314a/1282c19:dd:d9:dd:c25:c25:94de:314a
762c19:dd:d9:dd:c25:c25:94de:314b/1282c19:dd:d9:dd:c25:c25:94de:314b
772c19:dd:d9:dd:c25:c25:94de:314c/1282c19:dd:d9:dd:c25:c25:94de:314c
782c19:dd:d9:dd:c25:c25:94de:314d/1282c19:dd:d9:dd:c25:c25:94de:314d
792c19:dd:d9:dd:c25:c25:94de:314e/1282c19:dd:d9:dd:c25:c25:94de:314e
802c19:dd:d9:dd:c25:c25:94de:314f/1282c19:dd:d9:dd:c25:c25:94de:314f
812c19:dd:d9:dd:c25:c25:94de:3150/1282c19:dd:d9:dd:c25:c25:94de:3150
822c19:dd:d9:dd:c25:c25:94de:3151/1282c19:dd:d9:dd:c25:c25:94de:3151
832c19:dd:d9:dd:c25:c25:94de:3152/1282c19:dd:d9:dd:c25:c25:94de:3152
842c19:dd:d9:dd:c25:c25:94de:3153/1282c19:dd:d9:dd:c25:c25:94de:3153
852c19:dd:d9:dd:c25:c25:94de:3154/1282c19:dd:d9:dd:c25:c25:94de:3154
862c19:dd:d9:dd:c25:c25:94de:3155/1282c19:dd:d9:dd:c25:c25:94de:3155
872c19:dd:d9:dd:c25:c25:94de:3156/1282c19:dd:d9:dd:c25:c25:94de:3156
882c19:dd:d9:dd:c25:c25:94de:3157/1282c19:dd:d9:dd:c25:c25:94de:3157
892c19:dd:d9:dd:c25:c25:94de:3158/1282c19:dd:d9:dd:c25:c25:94de:3158
902c19:dd:d9:dd:c25:c25:94de:3159/1282c19:dd:d9:dd:c25:c25:94de:3159
912c19:dd:d9:dd:c25:c25:94de:315a/1282c19:dd:d9:dd:c25:c25:94de:315a
922c19:dd:d9:dd:c25:c25:94de:315b/1282c19:dd:d9:dd:c25:c25:94de:315b
932c19:dd:d9:dd:c25:c25:94de:315c/1282c19:dd:d9:dd:c25:c25:94de:315c
942c19:dd:d9:dd:c25:c25:94de:315d/1282c19:dd:d9:dd:c25:c25:94de:315d
952c19:dd:d9:dd:c25:c25:94de:315e/1282c19:dd:d9:dd:c25:c25:94de:315e
962c19:dd:d9:dd:c25:c25:94de:315f/1282c19:dd:d9:dd:c25:c25:94de:315f
972c19:dd:d9:dd:c25:c25:94de:3160/1282c19:dd:d9:dd:c25:c25:94de:3160
982c19:dd:d9:dd:c25:c25:94de:3161/1282c19:dd:d9:dd:c25:c25:94de:3161
992c19:dd:d9:dd:c25:c25:94de:3162/1282c19:dd:d9:dd:c25:c25:94de:3162
1002c19:dd:d9:dd:c25:c25:94de:3163/1282c19:dd:d9:dd:c25:c25:94de:3163
1012c19:dd:d9:dd:c25:c25:94de:3164/1282c19:dd:d9:dd:c25:c25:94de:3164
1022c19:dd:d9:dd:c25:c25:94de:3165/1282c19:dd:d9:dd:c25:c25:94de:3165
1032c19:dd:d9:dd:c25:c25:94de:3166/1282c19:dd:d9:dd:c25:c25:94de:3166
1042c19:dd:d9:dd:c25:c25:94de:3167/1282c19:dd:d9:dd:c25:c25:94de:3167
1052c19:dd:d9:dd:c25:c25:94de:3168/1282c19:dd:d9:dd:c25:c25:94de:3168
1062c19:dd:d9:dd:c25:c25:94de:3169/1282c19:dd:d9:dd:c25:c25:94de:3169
1072c19:dd:d9:dd:c25:c25:94de:316a/1282c19:dd:d9:dd:c25:c25:94de:316a
1082c19:dd:d9:dd:c25:c25:94de:316b/1282c19:dd:d9:dd:c25:c25:94de:316b
1092c19:dd:d9:dd:c25:c25:94de:316c/1282c19:dd:d9:dd:c25:c25:94de:316c
1102c19:dd:d9:dd:c25:c25:94de:316d/1282c19:dd:d9:dd:c25:c25:94de:316d
1112c19:dd:d9:dd:c25:c25:94de:316e/1282c19:dd:d9:dd:c25:c25:94de:316e
1122c19:dd:d9:dd:c25:c25:94de:316f/1282c19:dd:d9:dd:c25:c25:94de:316f
1132c19:dd:d9:dd:c25:c25:94de:3170/1282c19:dd:d9:dd:c25:c25:94de:3170
1142c19:dd:d9:dd:c25:c25:94de:3171/1282c19:dd:d9:dd:c25:c25:94de:3171
1152c19:dd:d9:dd:c25:c25:94de:3172/1282c19:dd:d9:dd:c25:c25:94de:3172
1162c19:dd:d9:dd:c25:c25:94de:3173/1282c19:dd:d9:dd:c25:c25:94de:3173
1172c19:dd:d9:dd:c25:c25:94de:3174/1282c19:dd:d9:dd:c25:c25:94de:3174
1182c19:dd:d9:dd:c25:c25:94de:3175/1282c19:dd:d9:dd:c25:c25:94de:3175
1192c19:dd:d9:dd:c25:c25:94de:3176/1282c19:dd:d9:dd:c25:c25:94de:3176
1202c19:dd:d9:dd:c25:c25:94de:3177/1282c19:dd:d9:dd:c25:c25:94de:3177
1212c19:dd:d9:dd:c25:c25:94de:3178/1282c19:dd:d9:dd:c25:c25:94de:3178
1222c19:dd:d9:dd:c25:c25:94de:3179/1282c19:dd:d9:dd:c25:c25:94de:3179
1232c19:dd:d9:dd:c25:c25:94de:317a/1282c19:dd:d9:dd:c25:c25:94de:317a
1242c19:dd:d9:dd:c25:c25:94de:317b/1282c19:dd:d9:dd:c25:c25:94de:317b
1252c19:dd:d9:dd:c25:c25:94de:317c/1282c19:dd:d9:dd:c25:c25:94de:317c
1262c19:dd:d9:dd:c25:c25:94de:317d/1282c19:dd:d9:dd:c25:c25:94de:317d
1272c19:dd:d9:dd:c25:c25:94de:317e/1282c19:dd:d9:dd:c25:c25:94de:317e
1282c19:dd:d9:dd:c25:c25:94de:317f/1282c19:dd:d9:dd:c25:c25:94de:317f
1292c19:dd:d9:dd:c25:c25:94de:3180/1282c19:dd:d9:dd:c25:c25:94de:3180
1302c19:dd:d9:dd:c25:c25:94de:3181/1282c19:dd:d9:dd:c25:c25:94de:3181
1312c19:dd:d9:dd:c25:c25:94de:3182/1282c19:dd:d9:dd:c25:c25:94de:3182
1322c19:dd:d9:dd:c25:c25:94de:3183/1282c19:dd:d9:dd:c25:c25:94de:3183
1332c19:dd:d9:dd:c25:c25:94de:3184/1282c19:dd:d9:dd:c25:c25:94de:3184
1342c19:dd:d9:dd:c25:c25:94de:3185/1282c19:dd:d9:dd:c25:c25:94de:3185
1352c19:dd:d9:dd:c25:c25:94de:3186/1282c19:dd:d9:dd:c25:c25:94de:3186
1362c19:dd:d9:dd:c25:c25:94de:3187/1282c19:dd:d9:dd:c25:c25:94de:3187
1372c19:dd:d9:dd:c25:c25:94de:3188/1282c19:dd:d9:dd:c25:c25:94de:3188
1382c19:dd:d9:dd:c25:c25:94de:3189/1282c19:dd:d9:dd:c25:c25:94de:3189
1392c19:dd:d9:dd:c25:c25:94de:318a/1282c19:dd:d9:dd:c25:c25:94de:318a
1402c19:dd:d9:dd:c25:c25:94de:318b/1282c19:dd:d9:dd:c25:c25:94de:318b
1412c19:dd:d9:dd:c25:c25:94de:318c/1282c19:dd:d9:dd:c25:c25:94de:318c
1422c19:dd:d9:dd:c25:c25:94de:318d/1282c19:dd:d9:dd:c25:c25:94de:318d
1432c19:dd:d9:dd:c25:c25:94de:318e/1282c19:dd:d9:dd:c25:c25:94de:318e
1442c19:dd:d9:dd:c25:c25:94de:318f/1282c19:dd:d9:dd:c25:c25:94de:318f
1452c19:dd:d9:dd:c25:c25:94de:3190/1282c19:dd:d9:dd:c25:c25:94de:3190
1462c19:dd:d9:dd:c25:c25:94de:3191/1282c19:dd:d9:dd:c25:c25:94de:3191
1472c19:dd:d9:dd:c25:c25:94de:3192/1282c19:dd:d9:dd:c25:c25:94de:3192
1482c19:dd:d9:dd:c25:c25:94de:3193/1282c19:dd:d9:dd:c25:c25:94de:3193
1492c19:dd:d9:dd:c25:c25:94de:3194/1282c19:dd:d9:dd:c25:c25:94de:3194
1502c19:dd:d9:dd:c25:c25:94de:3195/1282c19:dd:d9:dd:c25:c25:94de:3195
1512c19:dd:d9:dd:c25:c25:94de:3196/1282c19:dd:d9:dd:c25:c25:94de:3196
1522c19:dd:d9:dd:c25:c25:94de:3197/1282c19:dd:d9:dd:c25:c25:94de:3197
1532c19:dd:d9:dd:c25:c25:94de:3198/1282c19:dd:d9:dd:c25:c25:94de:3198
1542c19:dd:d9:dd:c25:c25:94de:3199/1282c19:dd:d9:dd:c25:c25:94de:3199
1552c19:dd:d9:dd:c25:c25:94de:319a/1282c19:dd:d9:dd:c25:c25:94de:319a
1562c19:dd:d9:dd:c25:c25:94de:319b/1282c19:dd:d9:dd:c25:c25:94de:319b
1572c19:dd:d9:dd:c25:c25:94de:319c/1282c19:dd:d9:dd:c25:c25:94de:319c
1582c19:dd:d9:dd:c25:c25:94de:319d/1282c19:dd:d9:dd:c25:c25:94de:319d
1592c19:dd:d9:dd:c25:c25:94de:319e/1282c19:dd:d9:dd:c25:c25:94de:319e
1602c19:dd:d9:dd:c25:c25:94de:319f/1282c19:dd:d9:dd:c25:c25:94de:319f
1612c19:dd:d9:dd:c25:c25:94de:31a0/1282c19:dd:d9:dd:c25:c25:94de:31a0
1622c19:dd:d9:dd:c25:c25:94de:31a1/1282c19:dd:d9:dd:c25:c25:94de:31a1
1632c19:dd:d9:dd:c25:c25:94de:31a2/1282c19:dd:d9:dd:c25:c25:94de:31a2
1642c19:dd:d9:dd:c25:c25:94de:31a3/1282c19:dd:d9:dd:c25:c25:94de:31a3
1652c19:dd:d9:dd:c25:c25:94de:31a4/1282c19:dd:d9:dd:c25:c25:94de:31a4
1662c19:dd:d9:dd:c25:c25:94de:31a5/1282c19:dd:d9:dd:c25:c25:94de:31a5
1672c19:dd:d9:dd:c25:c25:94de:31a6/1282c19:dd:d9:dd:c25:c25:94de:31a6
1682c19:dd:d9:dd:c25:c25:94de:31a7/1282c19:dd:d9:dd:c25:c25:94de:31a7
1692c19:dd:d9:dd:c25:c25:94de:31a8/1282c19:dd:d9:dd:c25:c25:94de:31a8
1702c19:dd:d9:dd:c25:c25:94de:31a9/1282c19:dd:d9:dd:c25:c25:94de:31a9
1712c19:dd:d9:dd:c25:c25:94de:31aa/1282c19:dd:d9:dd:c25:c25:94de:31aa
1722c19:dd:d9:dd:c25:c25:94de:31ab/1282c19:dd:d9:dd:c25:c25:94de:31ab
1732c19:dd:d9:dd:c25:c25:94de:31ac/1282c19:dd:d9:dd:c25:c25:94de:31ac
1742c19:dd:d9:dd:c25:c25:94de:31ad/1282c19:dd:d9:dd:c25:c25:94de:31ad
1752c19:dd:d9:dd:c25:c25:94de:31ae/1282c19:dd:d9:dd:c25:c25:94de:31ae
1762c19:dd:d9:dd:c25:c25:94de:31af/1282c19:dd:d9:dd:c25:c25:94de:31af
1772c19:dd:d9:dd:c25:c25:94de:31b0/1282c19:dd:d9:dd:c25:c25:94de:31b0
1782c19:dd:d9:dd:c25:c25:94de:31b1/1282c19:dd:d9:dd:c25:c25:94de:31b1
1792c19:dd:d9:dd:c25:c25:94de:31b2/1282c19:dd:d9:dd:c25:c25:94de:31b2
1802c19:dd:d9:dd:c25:c25:94de:31b3/1282c19:dd:d9:dd:c25:c25:94de:31b3
1812c19:dd:d9:dd:c25:c25:94de:31b4/1282c19:dd:d9:dd:c25:c25:94de:31b4
1822c19:dd:d9:dd:c25:c25:94de:31b5/1282c19:dd:d9:dd:c25:c25:94de:31b5
1832c19:dd:d9:dd:c25:c25:94de:31b6/1282c19:dd:d9:dd:c25:c25:94de:31b6
1842c19:dd:d9:dd:c25:c25:94de:31b7/1282c19:dd:d9:dd:c25:c25:94de:31b7
1852c19:dd:d9:dd:c25:c25:94de:31b8/1282c19:dd:d9:dd:c25:c25:94de:31b8
1862c19:dd:d9:dd:c25:c25:94de:31b9/1282c19:dd:d9:dd:c25:c25:94de:31b9
1872c19:dd:d9:dd:c25:c25:94de:31ba/1282c19:dd:d9:dd:c25:c25:94de:31ba
1882c19:dd:d9:dd:c25:c25:94de:31bb/1282c19:dd:d9:dd:c25:c25:94de:31bb
1892c19:dd:d9:dd:c25:c25:94de:31bc/1282c19:dd:d9:dd:c25:c25:94de:31bc
1902c19:dd:d9:dd:c25:c25:94de:31bd/1282c19:dd:d9:dd:c25:c25:94de:31bd
1912c19:dd:d9:dd:c25:c25:94de:31be/1282c19:dd:d9:dd:c25:c25:94de:31be
1922c19:dd:d9:dd:c25:c25:94de:31bf/1282c19:dd:d9:dd:c25:c25:94de:31bf
1932c19:dd:d9:dd:c25:c25:94de:31c0/1282c19:dd:d9:dd:c25:c25:94de:31c0
1942c19:dd:d9:dd:c25:c25:94de:31c1/1282c19:dd:d9:dd:c25:c25:94de:31c1
1952c19:dd:d9:dd:c25:c25:94de:31c2/1282c19:dd:d9:dd:c25:c25:94de:31c2
1962c19:dd:d9:dd:c25:c25:94de:31c3/1282c19:dd:d9:dd:c25:c25:94de:31c3
1972c19:dd:d9:dd:c25:c25:94de:31c4/1282c19:dd:d9:dd:c25:c25:94de:31c4
1982c19:dd:d9:dd:c25:c25:94de:31c5/1282c19:dd:d9:dd:c25:c25:94de:31c5
1992c19:dd:d9:dd:c25:c25:94de:31c6/1282c19:dd:d9:dd:c25:c25:94de:31c6
2002c19:dd:d9:dd:c25:c25:94de:31c7/1282c19:dd:d9:dd:c25:c25:94de:31c7
2012c19:dd:d9:dd:c25:c25:94de:31c8/1282c19:dd:d9:dd:c25:c25:94de:31c8
2022c19:dd:d9:dd:c25:c25:94de:31c9/1282c19:dd:d9:dd:c25:c25:94de:31c9
2032c19:dd:d9:dd:c25:c25:94de:31ca/1282c19:dd:d9:dd:c25:c25:94de:31ca
2042c19:dd:d9:dd:c25:c25:94de:31cb/1282c19:dd:d9:dd:c25:c25:94de:31cb
2052c19:dd:d9:dd:c25:c25:94de:31cc/1282c19:dd:d9:dd:c25:c25:94de:31cc
2062c19:dd:d9:dd:c25:c25:94de:31cd/1282c19:dd:d9:dd:c25:c25:94de:31cd
2072c19:dd:d9:dd:c25:c25:94de:31ce/1282c19:dd:d9:dd:c25:c25:94de:31ce
2082c19:dd:d9:dd:c25:c25:94de:31cf/1282c19:dd:d9:dd:c25:c25:94de:31cf
2092c19:dd:d9:dd:c25:c25:94de:31d0/1282c19:dd:d9:dd:c25:c25:94de:31d0
2102c19:dd:d9:dd:c25:c25:94de:31d1/1282c19:dd:d9:dd:c25:c25:94de:31d1
2112c19:dd:d9:dd:c25:c25:94de:31d2/1282c19:dd:d9:dd:c25:c25:94de:31d2
2122c19:dd:d9:dd:c25:c25:94de:31d3/1282c19:dd:d9:dd:c25:c25:94de:31d3
2132c19:dd:d9:dd:c25:c25:94de:31d4/1282c19:dd:d9:dd:c25:c25:94de:31d4
2142c19:dd:d9:dd:c25:c25:94de:31d5/1282c19:dd:d9:dd:c25:c25:94de:31d5
2152c19:dd:d9:dd:c25:c25:94de:31d6/1282c19:dd:d9:dd:c25:c25:94de:31d6
2162c19:dd:d9:dd:c25:c25:94de:31d7/1282c19:dd:d9:dd:c25:c25:94de:31d7
2172c19:dd:d9:dd:c25:c25:94de:31d8/1282c19:dd:d9:dd:c25:c25:94de:31d8
2182c19:dd:d9:dd:c25:c25:94de:31d9/1282c19:dd:d9:dd:c25:c25:94de:31d9
2192c19:dd:d9:dd:c25:c25:94de:31da/1282c19:dd:d9:dd:c25:c25:94de:31da
2202c19:dd:d9:dd:c25:c25:94de:31db/1282c19:dd:d9:dd:c25:c25:94de:31db
2212c19:dd:d9:dd:c25:c25:94de:31dc/1282c19:dd:d9:dd:c25:c25:94de:31dc
2222c19:dd:d9:dd:c25:c25:94de:31dd/1282c19:dd:d9:dd:c25:c25:94de:31dd
2232c19:dd:d9:dd:c25:c25:94de:31de/1282c19:dd:d9:dd:c25:c25:94de:31de
2242c19:dd:d9:dd:c25:c25:94de:31df/1282c19:dd:d9:dd:c25:c25:94de:31df
2252c19:dd:d9:dd:c25:c25:94de:31e0/1282c19:dd:d9:dd:c25:c25:94de:31e0
2262c19:dd:d9:dd:c25:c25:94de:31e1/1282c19:dd:d9:dd:c25:c25:94de:31e1
2272c19:dd:d9:dd:c25:c25:94de:31e2/1282c19:dd:d9:dd:c25:c25:94de:31e2
2282c19:dd:d9:dd:c25:c25:94de:31e3/1282c19:dd:d9:dd:c25:c25:94de:31e3
2292c19:dd:d9:dd:c25:c25:94de:31e4/1282c19:dd:d9:dd:c25:c25:94de:31e4
2302c19:dd:d9:dd:c25:c25:94de:31e5/1282c19:dd:d9:dd:c25:c25:94de:31e5
2312c19:dd:d9:dd:c25:c25:94de:31e6/1282c19:dd:d9:dd:c25:c25:94de:31e6
2322c19:dd:d9:dd:c25:c25:94de:31e7/1282c19:dd:d9:dd:c25:c25:94de:31e7
2332c19:dd:d9:dd:c25:c25:94de:31e8/1282c19:dd:d9:dd:c25:c25:94de:31e8
2342c19:dd:d9:dd:c25:c25:94de:31e9/1282c19:dd:d9:dd:c25:c25:94de:31e9
2352c19:dd:d9:dd:c25:c25:94de:31ea/1282c19:dd:d9:dd:c25:c25:94de:31ea
2362c19:dd:d9:dd:c25:c25:94de:31eb/1282c19:dd:d9:dd:c25:c25:94de:31eb
2372c19:dd:d9:dd:c25:c25:94de:31ec/1282c19:dd:d9:dd:c25:c25:94de:31ec
2382c19:dd:d9:dd:c25:c25:94de:31ed/1282c19:dd:d9:dd:c25:c25:94de:31ed
2392c19:dd:d9:dd:c25:c25:94de:31ee/1282c19:dd:d9:dd:c25:c25:94de:31ee
2402c19:dd:d9:dd:c25:c25:94de:31ef/1282c19:dd:d9:dd:c25:c25:94de:31ef
2412c19:dd:d9:dd:c25:c25:94de:31f0/1282c19:dd:d9:dd:c25:c25:94de:31f0
2422c19:dd:d9:dd:c25:c25:94de:31f1/1282c19:dd:d9:dd:c25:c25:94de:31f1
2432c19:dd:d9:dd:c25:c25:94de:31f2/1282c19:dd:d9:dd:c25:c25:94de:31f2
2442c19:dd:d9:dd:c25:c25:94de:31f3/1282c19:dd:d9:dd:c25:c25:94de:31f3
2452c19:dd:d9:dd:c25:c25:94de:31f4/1282c19:dd:d9:dd:c25:c25:94de:31f4
2462c19:dd:d9:dd:c25:c25:94de:31f5/1282c19:dd:d9:dd:c25:c25:94de:31f5
2472c19:dd:d9:dd:c25:c25:94de:31f6/1282c19:dd:d9:dd:c25:c25:94de:31f6
2482c19:dd:d9:dd:c25:c25:94de:31f7/1282c19:dd:d9:dd:c25:c25:94de:31f7
2492c19:dd:d9:dd:c25:c25:94de:31f8/1282c19:dd:d9:dd:c25:c25:94de:31f8
2502c19:dd:d9:dd:c25:c25:94de:31f9/1282c19:dd:d9:dd:c25:c25:94de:31f9
2512c19:dd:d9:dd:c25:c25:94de:31fa/1282c19:dd:d9:dd:c25:c25:94de:31fa
2522c19:dd:d9:dd:c25:c25:94de:31fb/1282c19:dd:d9:dd:c25:c25:94de:31fb
2532c19:dd:d9:dd:c25:c25:94de:31fc/1282c19:dd:d9:dd:c25:c25:94de:31fc
2542c19:dd:d9:dd:c25:c25:94de:31fd/1282c19:dd:d9:dd:c25:c25:94de:31fd
2552c19:dd:d9:dd:c25:c25:94de:31fe/1282c19:dd:d9:dd:c25:c25:94de:31fe
2562c19:dd:d9:dd:c25:c25:94de:31ff/1282c19:dd:d9:dd:c25:c25:94de:31ff

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.