<div>
@jorge diaz &nbsp;- Thank you and I was happy to help.
</div>


@jorge diaz  - Thank you and I was happy to help.

<div>
<div class="content wysiwyg-content">
Hi There,<br />
<br />
Can anyone help understand subnetting... i have a Cisco SMB SRP541W unit.<br />
<br />
this is what is is, i want to create a fw rule to allow traffic from a host based on its IP address, let's say that i want to allow traffic from 74.90.225.174 to my network, i don't know the source's subnet mask, just the IP. &nbsp;When i create a rule i enter the IP address but a subnet mask is required, i entered or 0.0.0.0 and it fails (meaning the rule can't be create). if i use 255.255.255.255 it seems to create the rule but is it right? &nbsp;Is the latter one the right choice if i don't know the source's sm?<br />
<br />
thanks..
</div>
</div>


Hi There,

Can anyone help understand subnetting... i have a Cisco SMB SRP541W unit.

this is what is is, i want to create a fw rule to allow traffic from a host based on its IP address, let's say that i want to allow traffic from 74.90.225.174 to my network, i don't know the source's subnet mask, just the IP.  When i create a rule i enter the IP address but a subnet mask is required, i entered or 0.0.0.0 and it fails (meaning the rule can't be create). if i use 255.255.255.255 it seems to create the rule but is it right?  Is the latter one the right choice if i don't know the source's sm?

thanks..

IP Subnetting

Transmission Control Protocol/Internet Protocol (TCP/IP) is the set of networking protocols that define end-to-end connectivity specifying how data should be packeted, addressed, transmitted, routed and received at the destination. This functionality is organized into four abstraction layers which are used to sort all related protocols according to the scope of networking involved.