Tools – Wildcard Calculator

IP: 10.96.20.0 Wildcard Mask:0.31.3.255
[WildCard calculations for Cisco Devices, support for others to be added.]
Octet 1
Octet 2
Octet 3
Octet 4
IP 10.96.20.0
00001010
.
01100000
.
00010100
.
00000000
Wildcard Mask 0.31.3.255
00000000
.
00011111
.
00000011
.
11111111
Bit Pattern 00001010 . 011????? . 000101?? . ????????
Networks Matched in [brackets]
(examples)
[10]
.
[96 - 127]
.
[20 - 23]
.
[0 - 255]
Entry for Cisco Standard access-list:
ip access-list standard IPV4.AS
permit 10.96.20.0 0.31.3.255
Result Breakdown:
IP & WildCard Octet 1
[10.96.20.0 with WildCard mask 0.31.3.255]
Octet bits value/pos 128
bit 8
64
bit 7
32
bit 6
16
bit 5
8
bit 4
4
bit 3
2
bit 2
1
bit 1
IP: 10 0 0 0 0 1 0 1 0
WC:(?) 0 0 0 0 0 0 0 0 0
= = = = = = = =
Bit pattern:(?) 0 0 0 0 1 0 1 0

IP & WildCard Octet 2
[10.96.20.0 with WildCard mask 0.31.3.255]
Octet bits value/pos 128
bit 8
64
bit 7
32
bit 6
16
bit 5
8
bit 4
4
bit 3
2
bit 2
1
bit 1
IP: 96 0 1 1 0 0 0 0 0
WC:(?) 31 0 0 0 1 1 1 1 1
= = = = = = = =
Bit pattern:(?) 0 1 1 0 or 1 0 or 1 0 or 1 0 or 1 0 or 1

IP & WildCard Octet 3
[10.96.20.0 with WildCard mask 0.31.3.255]
Octet bits value/pos 128
bit 8
64
bit 7
32
bit 6
16
bit 5
8
bit 4
4
bit 3
2
bit 2
1
bit 1
IP: 20 0 0 0 1 0 1 0 0
WC:(?) 3 0 0 0 0 0 0 1 1
= = = = = = = =
Bit pattern:(?) 0 0 0 1 0 1 0 or 1 0 or 1

IP & WildCard Octet 4
[10.96.20.0 with WildCard mask 0.31.3.255]
Octet bits value/pos: 128
bit 8
64
bit 7
32
bit 6
16
bit 5
8
bit 4
4
bit 3
2
bit 2
1
bit 1
IP: 0 0 0 0 0 0 0 0 0
WC:(?) 255 1 1 1 1 1 1 1 1
= = = = = = = =
Bit pattern:(?) 0 or 1 0 or 1 0 or 1 0 or 1 0 or 1 0 or 1 0 or 1 0 or 1

Use the calculators at your own risk.
version:
V0.4

4 thoughts on “Tools – Wildcard Calculator”

  1. Hey, I hope someone will find this Calculator useful, it was mostly aimed at wildcard masks for Cisco equipment. I will make a setting to change it to work for Juniper devices as well.
    Any suggestions & Feedback will be more than welcome.

  2. Excellent tool, thank you very much! Please keep this active as its very useful, you must get loads of hits as not many sites do proper wild card calculations. This works perfectly!

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