| MCSA 70-741 Mise en réseau avec Windows Server 2016 (22741A) |
Module 03: Implémentation de IPv6Sommaire
Vue d’ensemble de l’adressage IPv6Types of IPv6 AddressesIl exsite 3 catégories d' adresses
Particularities■ There’s no such thing as a broadcast in IPv6 because it uses multicast traffic instead.■ And there are two other types of communications as well: unicast,which is the same as it is in IPv4, and a new type called anycast. We’re all familiar with IPv4’s unicast, broadcast, and multicast addresses that basically define who or at least how many other devices we’re talking to. But as I mentioned, IPv6 modifies that trio and introduces the anycast. Broadcasts, as we know them, have been eliminated in IPv6 because of their cumbersome inefficiency and basic tendency to drive us insane! So let’s find out what each of these types of IPv6 addressing and communication methods do for us:Special IPv6 addresses0:0:0:0:0:0:0:0 Equals "::" . This is the equivalent of IPv4’s 0.0.0.0 and is typicallythe source address of a host before the host receives an IP address when you’re using DHCP-driven stateful configuration. 0:0:0:0:0:0:0:1 Equals "::1" . The equivalent of 127.0.0.1 in IPv4. 0:0:0:0:0:0:192.168.100.1 This is how an IPv4 address would be written in a mixed IPv6/IPv4 network environment. 2000::/3 The global unicast address range. 2001:0DB8::/32 Also reserved for examples and documentation. 2002::/16 Used with 6-to-4 tunneling, which is an IPv4-to-IPv6 transition system. The structure allows IPv6 packets to be transmitted over an IPv4 network without the need to configure explicit tunnels. FC00::/7 The unique local unicast range. FE80::/10 The link-local unicast range. FF00::/8 The multicast range. 3FFF:FFFF::/32 Reserved for examples and documentation. UnicastUnicast AddressesUnicast Packets addressed to a unicast address are delivered to a single interface.
Global unicast addresses (2000::/3) These are your typical publicly routable addresses and they’re the same as in IPv4. Global addresses start at 2000::/3. The ISP can provide you with a minimum /48 network ID, which in turn provides you 16-bits to create a unique 64-bit router interface address. The last 64-bits are the unique host ID. Link-local addresses (FE80::/10) These are like the Automatic Private IP Address (APIPA) addresses that Microsoft uses to automatically provide addresses in IPv4 in that they’re not meant to be routed. In IPv6 they start with FE80::/10. Think of these addresses as handy tools that give you the ability to throw a temporary LAN together for meetings or create a small LAN that’s not going to be routed but still needs to share and access files and services locally. Unique local addresses (FC00::/7) These addresses are also intended for nonrouting purposes over the Internet, but they are nearly globally unique, so it’s unlikely you’ll ever have one of them overlap. Unique local addresses were designed to replace site-local addresses, so they basically do almost exactly what IPv4 private addresses do: allow communication throughout a site while being routable to multiple local networks. Site-local addresses were deprecated as of September 2004. Resume
MulticastMulticastMulticast (FF00::/8) Again, as in IPv4, packets addressed to a multicast address are delivered to all interfaces tuned into the multicast address. Sometimes people call them “one-to-many” addresses. It’s really easy to spot a multicast address in IPv6 because they always start with FF. We’ll get deeper into multicast operation coming up in, “How IPv6 Works in an Internetwork.” Le protocole IPv6 généralise l'utilisation des adresses multicast qui remplacent les adresses de type broadcast qui n'existent plus en IPv6 . la raison de cette disparition est que l'émission d'un paquet broadcast était très pénalisante pour toutes les machines se trouvant sur um meme lien. Une adresse multicast est une adresse désignant un groupe d'interfaces donné. Une interface est libre de s'abonner à un groupe ou de le quitter à tout moment , c'est donc moins pénalisant qu'en IPv4. Le format des adresses multicast est le suivant:
AnycastAnycastAnycast Like multicast addresses, an anycast address identifies multiple interfaces on multiple devices. But there’s a big difference: the anycast packet is delivered to only one device—actually, to the closest one it finds defined in terms of routing distance. This address is special because you can apply a single address to more than one host. These are referred to as “one-to-nearest” addresses. Anycast addresses are typically only configured on routers, never hosts, and a source address could never be an anycast address. Of note is that the IETF did reserve the top 128 addresses for each /64 for use with anycast addresses. You’re probably wondering if there are any special, reserved addresses in IPv6 because you know they’re there in IPv4. Anycast communication allows the same address to be placed on more than one device so that when traffic is sent to the device service addressedin this way, it’s routed to the nearest host that shares the same address. And this is just the beginning—we’ll get into the various types of communication later in the section called, “Address Types.” Configuration d’un hôte IPv6Implémentation IPv6 et cohabitation avec IPv4Transition d’IPv4 à IPv6 |
|||||||||||||||||||
