<p>See also <a target="_blank" href="https://www.ietf.org/rfc/rfc1878.txt">RFC 1878</a>.</p>
<h2 id="heading-guide-to-sub-class-c-blocks">Guide to sub-class C blocks</h2>
<p><img src="https://cdn.hashnode.com/res/hashnode/image/upload/v1658229279178/dt0bXrKV6.png" alt="Screenshot 2022-07-19 at 4.44.29 PM.png" /></p>
<p><img src="https://cdn.hashnode.com/res/hashnode/image/upload/v1658229746990/PBoDqhYEu.png" alt="Screenshot 2022-07-19 at 4.52.15 PM.png" /></p>


See also [RFC 1878](https://www.ietf.org/rfc/rfc1878.txt).


## Guide to sub-class C blocks

![Screenshot 2022-07-19 at 4.44.29 PM.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1658229279178/dt0bXrKV6.png align="left")



![Screenshot 2022-07-19 at 4.52.15 PM.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1658229746990/PBoDqhYEu.png align="left")


Subnet Mask Cheat Sheet

Guide to sub-class C blocks