So what’s so fabulous about IPv6? Is it really the answer to our coming dilemma? Is it really worth it to upgrade from IPv4? All good questions—you may even think of a few more. Of course, there’s going to be that group of people with the time-tested and well-known “resistance to change syndrome,” but don’t listen to them. If we had done that years ago, we’d still be waiting weeks, even months for our mail to arrive via horseback. Instead, just know that the answer is a resounding YES!
Not only does IPv6 give us lots of addresses (3.4×10^38 = definitely enough), but there are many other features built into this version that make it well worth the cost, time, and effort required to migrate to it. Later in the chapter I’ll talk about all that effort in the section called “Migrating to IPv6.” In it, I’ll cover some of the transition types required to move from version 4 to version 6, and I promise you’ll discover that the huge benefits of migrating will vastly outweigh any associated cons.
Today’s networks, as well as the Internet, have a ton of unforeseen requirements that simply were not considerations when IPv4 was created. We’ve tried to compensate with a collection of add-ons that can actually make implementing them more difficult than they would be if they were required by a standard. By default, IPv6 has improved upon and included many of those features as standard and mandatory. One of these sweet new standards is IPSec—a feature that provides end-to-end security “Wide Area Networks.” Another little beauty is known as mobility, and as its name suggests, it allows a device to roam from one network to another without dropping connections. But it’s the efficiency features that are really going to rock the house! For starters, the header in an IPv6 packet have half the fields, and they are aligned to 64 bits, which gives us some seriously souped-up processing speed—compared to IPv4, lookups happen at light speed!
Most of the information that used to be bound into the IPv4 header was taken out, and now you can choose to put it, or parts of it, back into the header in the form of optional extension headers that follow the basic header fields.
And of course there’s that whole new universe of addresses (3.4 x 10^38) we talked about already. But where did we get them? Did that Criss Angel–Mindfreak dude just show up and, Blammo? I mean, that huge proliferation of addresses had to come from somewhere! Well it just so happens that IPv6 gives us a substantially larger address space, meaning the address is a whole lot bigger—four times bigger as a matter of fact!
An IPv6 address is actually 128 bits in length, and no worries—I’m going to break down the address piece by piece and show you exactly what it looks like coming up in the section “IPv6 Addressing and Expressions.” For now, let me just say that all that additional room permits more levels of hierarchy inside the address space and a more flexible address architecture. It also makes routing much more efficient and scalable because the addresses can be aggregated a lot more effectively. And IPv6 also allows multiple addresses for hosts and networks. This is especially important for enterprises jonesing for availability. Plus, the new version of IP now includes an expanded use of multicast communication (one device sending to many hosts or to a select group), which will also join in to boost efficiency on networks because communications will be more specific.
IPv4 uses broadcasts very prolifically, causing a bunch of problems, the worst of which is of course the dreaded broadcast storm—an uncontrolled deluge of forwarded broadcast traffic that can bring an entire network to its knees and devour every last bit of bandwidth. Another nasty thing about broadcast traffic is that it interrupts each and every device on the network. When a broadcast is sent out, every machine has to stop what it’s doing and respond to the traffic whether the broadcast is meant for it or not.
But smile everyone: There is no such thing as a broadcast in IPv6 because it uses multicast traffic instead. And there are two other types of communication as well: unicast, which is the same as it is in IPv4, and a new type called anycast. Anycast communication allows the same address to be placed on more than one device so that when traffic is sent to one device addressed in this way, it is routed to the nearest host that shares the same address. This is just the beginning—we’ll get more into the various types of communication in the section called “Address Types.”
Not only does IPv6 give us lots of addresses (3.4×10^38 = definitely enough), but there are many other features built into this version that make it well worth the cost, time, and effort required to migrate to it. Later in the chapter I’ll talk about all that effort in the section called “Migrating to IPv6.” In it, I’ll cover some of the transition types required to move from version 4 to version 6, and I promise you’ll discover that the huge benefits of migrating will vastly outweigh any associated cons.
Today’s networks, as well as the Internet, have a ton of unforeseen requirements that simply were not considerations when IPv4 was created. We’ve tried to compensate with a collection of add-ons that can actually make implementing them more difficult than they would be if they were required by a standard. By default, IPv6 has improved upon and included many of those features as standard and mandatory. One of these sweet new standards is IPSec—a feature that provides end-to-end security “Wide Area Networks.” Another little beauty is known as mobility, and as its name suggests, it allows a device to roam from one network to another without dropping connections. But it’s the efficiency features that are really going to rock the house! For starters, the header in an IPv6 packet have half the fields, and they are aligned to 64 bits, which gives us some seriously souped-up processing speed—compared to IPv4, lookups happen at light speed!
Most of the information that used to be bound into the IPv4 header was taken out, and now you can choose to put it, or parts of it, back into the header in the form of optional extension headers that follow the basic header fields.
And of course there’s that whole new universe of addresses (3.4 x 10^38) we talked about already. But where did we get them? Did that Criss Angel–Mindfreak dude just show up and, Blammo? I mean, that huge proliferation of addresses had to come from somewhere! Well it just so happens that IPv6 gives us a substantially larger address space, meaning the address is a whole lot bigger—four times bigger as a matter of fact!
An IPv6 address is actually 128 bits in length, and no worries—I’m going to break down the address piece by piece and show you exactly what it looks like coming up in the section “IPv6 Addressing and Expressions.” For now, let me just say that all that additional room permits more levels of hierarchy inside the address space and a more flexible address architecture. It also makes routing much more efficient and scalable because the addresses can be aggregated a lot more effectively. And IPv6 also allows multiple addresses for hosts and networks. This is especially important for enterprises jonesing for availability. Plus, the new version of IP now includes an expanded use of multicast communication (one device sending to many hosts or to a select group), which will also join in to boost efficiency on networks because communications will be more specific.
IPv4 uses broadcasts very prolifically, causing a bunch of problems, the worst of which is of course the dreaded broadcast storm—an uncontrolled deluge of forwarded broadcast traffic that can bring an entire network to its knees and devour every last bit of bandwidth. Another nasty thing about broadcast traffic is that it interrupts each and every device on the network. When a broadcast is sent out, every machine has to stop what it’s doing and respond to the traffic whether the broadcast is meant for it or not.
But smile everyone: There is no such thing as a broadcast in IPv6 because it uses multicast traffic instead. And there are two other types of communication as well: unicast, which is the same as it is in IPv4, and a new type called anycast. Anycast communication allows the same address to be placed on more than one device so that when traffic is sent to one device addressed in this way, it is routed to the nearest host that shares the same address. This is just the beginning—we’ll get more into the various types of communication in the section called “Address Types.”
DUDE! You STOLE MY chapters from my book and posted it here! You're a piece of shit! This is copied directly from my CCNA R/S Cisco Study Guide! Get this off your site now! EVERYTHING ON YOUR SITE IS STOLEN
ReplyDeleteYOU'RE A LOSER!