08-30-2007 06:56 AM - edited 03-03-2019 06:32 PM
What exactly is the wildcard mask doing in this line:
access-list 10 deny 192.168.10.128 0.0.0.31
Thanks
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08-30-2007 10:46 AM
Hi Guys,
For the Wildcard mask, I have a best practise to calculate it as follows:
1- you take the original Subnetmask of the Network ID and Subtract it by(255.255.255.255).
Example:
you have the Network : 192.168.10.128/27
192.168.10.128 255.255.255.224
** always take (255.255.255.255) -
(255.255.255.224)
equals = 0.0.0.31 (wildcard mask)
So the wildcard mask for 192.16.10.128/27
equals 192.168.10.128 0.0.0.31, which will match 31 bit hosts from 129 - 159.
Note: the last octet 159 is the broadcast of the subnet & its included in the calculation.
Regards,
Mohamed Sobair
08-30-2007 07:00 AM
It will deny all IP address start from
192.168.10.128 to 139 {129 and 140 both will comver}
Block size is 0 to 31 mean it covers 32 Ip address.
Regards,
Dharmesh Purohit
08-30-2007 07:05 AM
Hello,
The host range should be 192.168.10.129 to 192.168.10.158 which will be denied. Or i understood it wrong. 192.168.10.128/27
08-30-2007 07:08 AM
Purohit,
I guess it is a typo. Shouldn't it be 192.168.10.128 to 159 ?
regards,
08-30-2007 10:46 AM
Hi Guys,
For the Wildcard mask, I have a best practise to calculate it as follows:
1- you take the original Subnetmask of the Network ID and Subtract it by(255.255.255.255).
Example:
you have the Network : 192.168.10.128/27
192.168.10.128 255.255.255.224
** always take (255.255.255.255) -
(255.255.255.224)
equals = 0.0.0.31 (wildcard mask)
So the wildcard mask for 192.16.10.128/27
equals 192.168.10.128 0.0.0.31, which will match 31 bit hosts from 129 - 159.
Note: the last octet 159 is the broadcast of the subnet & its included in the calculation.
Regards,
Mohamed Sobair
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