Tips and Trick About Cisco

There was a time when names were somewhat arbitrary (if not outright capricious) and less-than-universal in their use. In the very beginning of the Internet, there were only hundreds of computers, and each one could be accessed using a mnemonic that was locally created by network administrators. This led to the [...]

Although NAT might sound like the perfect answer to virtually any scenario that involves a private network with Internet connectivity, it isn’t a panacea. In fact, it wouldn’t be very difficult to find knowledgeable network engineers who regard NAT as akin to crabgrass or kudzu, to name a pair of human-induced [...]

Network Address Translation (NAT) was developed specifically to counter the lone weakness inherent in the private addresses of RFC 1918. That’s not to suggest that it makes those nonunique addresses globally routable, because it doesn’t. Rather, it lets you translate those nonunique addresses to unique and routable addresses at the edge [...]

After the Internet became commercialized, its popularity soared. More importantly, so did the popularity of TCP/IP and its addressing architecture and space. Seemingly overnight, software engineers embraced the TCP/IP communications protocol suite and it became the de facto standard for networked communications between applications. As a direct result of this trend, [...]

Arguably the single most powerful advance experienced by the IPv4 address space is the capability known as supernetting. Before we delve too deeply into this topic, let’s dispel a very popular misperception. Supernetting was not introduced with CIDR! It was first specified in June 1992 in RFC 1338 as a standalone strategy [...]

The binary mathematics of the IP address space creates a marvelous natural symmetry in CIDR-compliant addresses. What at first glance appears to be an unmanageable jumble of numbers is actually a remarkably logical system. The key is remembering that the binary number system works based on powers of 2. For each [...]

CIDR was defined in RFCs 1517 through 1520, published in September 1993. As you peruse these documents, you can’t help but notice the sense of urgency with which the IETF was grasping for a solution to its impending address crisis. The Internet’s commercialization wrought a dramatic and rapid evolution in its [...]

The old saw still cuts true: Every little bit helps. In that spirit, the IETF attacked in all directions as it tried to stave off the impending, projected Date of Doom. Some of the measures, as you’ve seen so far in this chapter, were fairly dramatic, big-ticket items. Others were remarkably [...]

By 1992, the Internet was growing at rates that were straining it, its address space, and its physical and logical support infrastructures. Concern was running high among the techies behind the scenes at the IETF, but nobody else really seemed to grasp the problem. In November 1992, RFC 1380 was released. [...]

To better demonstrate how VLSM works in practical terms, Table 4-6 shows the progression from the sample network’s base address (192.168.125.0) through the defined subnets. Pay particular attention to the binary and decimal translations for each subnet’s base and terminal addresses. In decimal terms, you are progressing sequentially through the address [...]