《泉州CCNA之IPV6培训.pptVIP

Implementing IPv6 Defining IPv6 Addressing Simple and Efficient Header A simpler and more efficient header means: 64-bit aligned fields and fewer fields Hardware-based, efficient processing Improved routing efficiency and performance Faster forwarding rate with better scalability IPv4 and IPv6 Header Comparison IPv6 Address Representation Format: x:x:x:x:x:x:x:x, where x is a 16-bit hexadecimal field Case-insensitive for hexadecimal A, B, C, D, E, and F Leading zeros in a field are optional: 2031:0:130F:0:0:9C0:876A:130B Successive fields of 0 can be represented as ::, but only once per address. Examples: 2031:0000:130F:0000:0000:09C0:876A:130B 2031:0:130f::9c0:876a:130b 2031::130f::9c0:876a:130b—incorrect FF01:0:0:0:0:0:0:1 FF01::1 0:0:0:0:0:0:0:1 ::1 0:0:0:0:0:0:0:0 :: IPv6 Address Types IPv6 uses: Unicast Address is for a single interface. IPv6 has several types (for example, global and IPv4 mapped). Multicast One-to-many Enables more efficient use of the network Uses a larger address range Anycast One-to-nearest (allocated from unicast address space). Multiple devices share the same address. All anycast nodes should provide uniform service. Source devices send packets to anycast address. Routers decide on closest device to reach that destination. Suitable for load balancing and content delivery services. IPv6 Global Unicast (and Anycast) Addresses IPv6 has same address format for global unicast and for anycast. Uses a global routing prefix—a structure that enables aggregation upward, eventually to the ISP. A single interface may be assigned multiple addresses of any type (unicast, anycast, multicast). Every IPv6-enabled interface must contain at least one loopback (::1/128) and one link-local address. Optionally, every interface can have multiple unique local and global addresses. Anycast address is a global unicast address assigned to a set of interfaces (typically on different nodes). IPv6 anycast is used for a network multihomed to several ISPs th