Update README.md

Author: ScriptTiger

README.md

@@ -69,7 +69,7 @@ This classful routing approach worked for about a decade, until it reached a tip
 
 So, once more hastily gathering to solve the imminent IP exhausting problem while at the same time not breaking the system already in place, it was decided to then just drop the concept of classful routing altogether and just totally make the entire 32-bit address space a complete mix of routing and host information together, known as Classless Inter-Domain Routing (CIDR), where the number of bits used to designate a network and the number of bits used to designate a host were no longer pre-defined or fixed at all and both variable numbers within that 32-bit space. This meant that now IP blocks could be allocated more efficiently by bits and not just jump entire 8-bit ranges. However, it also meant that parsing the routing information and host information required a bit more processing power, and even an entirely new and separate 32-bit space that would now accompany the IPv4 address as a bit mask to untangle the network and host portions, known as a variable-length subnet mask, or VLSM. Despite maybe only adding an additional bitwise operation or two to the mix to enable classless routing, it must be kept in mind these additional steps would have to be done on every IP calculation from now on and were additional steps added to the very fabric of routing, which can add up to orders of magnitude more cycles used than before as you progress up the networking layers and add to the overall network latency for all network devices involved.
 
-Yes, subnet masks did not actually exist, nor were they needed, until CIDR came about in 1993! The entire concept of a subnet mask was invented as a Band-Aid to keep IPv4 going and was never actually part of the initial design! And please do not confuse subnet masks with subnetting, which had been around since 1985 and applies only to the network portion of the address to subdivide larger networks into smaller networks within a shared controlling authority and was never designed nor intended to be relevant in any way to the host portion of an address. Because VLSM emerged at the same time as a necessity to facilitate CIDR, both terms are often mistakenly used interchangeably. However, obviously, CIDR refers only to the specific type of routing, while VLSM refers only to the type of bit mask required to make the new CIDR possible. Which is why the popular "CIDR notation" describes a network prefix and the bit length of that prefix, since this prefix information is what is used for routing. Although, obviously, the VLSM can easily be derived from the prefix length, they both describe two different things and are used for two different purposes. And although this distinction may seem to be of little import and simply semantics, it is extremely important to keep this in mind when thinking about IPv6. IPv6 drops subnet masks entirely, since there are once again two clearly defined integers that no longer need to be untangled, but it does hold on to the concept of prefix lengths for subnetting purposes.
+Yes, subnet masks did not actually exist, nor were they needed, until CIDR came about in 1993! The entire concept of a subnet mask was invented as a Band-Aid to keep IPv4 going and was never actually part of the initial design! And please do not confuse subnet masks with subnetting, which had been around since 1985 and applies only to the network portion of the address to subdivide larger networks into smaller networks within a shared controlling authority and was never designed nor intended to be relevant in any way to the host portion of an address. Because VLSM emerged at the same time as a necessity to facilitate CIDR, both terms are often mistakenly used interchangeably. However, obviously, CIDR refers only to the specific type of routing, while VLSM refers only to the type of bit mask required to make the new CIDR possible. Which is why the popular "CIDR notation" describes a network prefix and the bit length of that prefix, since this prefix information is what is used for routing. Although, obviously, the VLSM and prefix length can easily be derived from each other and are thus closely linked, they both describe two different things and are used for two different purposes. And although this distinction may seem to be of little import and simply semantics, it is extremely important to keep this in mind when thinking about IPv6. IPv6 drops subnet masks entirely, since there are once again two clearly defined integers that no longer need to be untangled, but it does hold on to the concept of prefix lengths for subnetting purposes.
 
 Even after tricks like NAT (1994) came about to conserve global IP space further by masking entire networks behind one or more global IP addresses, it was still clear a new IP version would need to come about to resolve all of these growing issues, which would require a bit more intention and design than just a hasty meeting to solve a current crisis and keep the system only just one more slight step away from failure.