are ccna in demand

are ccna in demand.1980 1990 1 2000 2010Wave 1 :IPv4 For Wave 2: IPv4 Wave 3: IPv6Figure 9-1 IP IGP TimelineBy the early 1990s, commercial and technical factors were driving a second wave of routing protocol optimization in the world of IPv4. First, RIP-1 and IGRP had certain technical limitations, even though they were still very good on a technical level in the 1980s. The more powerful motivation for optimizing routing protocols was the unstoppable TCP/IP movement of the 1990s. Many enterprises were migrating from older, proprietary vector networks to networks built with routers, LANs, and TCP/IP. These enterprises demanded routing protocols that were more effective than ever before, including better metrics and convergence. All of these factors led directly to the new wave of IPv4 internal routing protocols: RIP Version 2 (RIP-2), OSPF Version 2 (OSPFv2), and EIGRP.1.2 Foundation Content 187(1) d(2) d(3) a(4) a and b(5) b(6) c188 Chapter 9 Understanding EIGRP ConceptsTip: As an additional note, many documents simply refer to EIGRP support for acquiring IPv4 routes as EIGRP, and EIGRP support for IPv6 as EIGRPV6. This book follows this convention. OSPFRFC defines specific versions, OSPFVersion2 (OSPFv2) for acquiring IPv4 routes, and OSPF Version 3 (OSPFv3) for acquiring IPv6 routes.Even today, EIGRP and OSPFv2 are still the two main competing protocols used by IPv4 routing protocols in modern enterprise IPv4 networks.RIP-2 is no longer a significant protocol, in part because it is not robust enough to calculate the hop count metric, but also because of its slower (and worse) convergence time. Even today, if you look at most enterprise networks, you will see that the routing protocols throughout the network are either EIGRP,or OSPFv2.So, with so many IPv4 routing protocols available, how does a network administrator choose which routing protocol to use? Well, consider the two key points that motivate an administrator to want to use EIGRP, as follows. , w/ rich wait EIGRP uses robust metrics based on link bandwidth and link latency so that routers can make the best routing choices. As shown in Figure 9-2 (Petri dish.