tailieunhanh - IPv6

IP version 6 (IPv6) was developed to overcome the limitations of the current standard, IP version 4 (IPv4). IPv4 allows end systems to communicate and forms the foundation of the Internet as we know it today. However, one of the major shortcomings of IPv4 is its limited amount of address space. The explosion of new IP-enabled devices and the growth of undeveloped regions have fueled the need for more addresses. | IPv6 CCNA Exploration version Overview IP version 6 (IPv6) was developed to overcome the limitations of the current standard, IP version 4 (IPv4). IPv4 allows end systems to communicate and forms the foundation of the Internet as we know it today. However, one of the major shortcomings of IPv4 is its limited amount of address space. The explosion of new IP-enabled devices and the growth of undeveloped regions have fueled the need for more addresses. In the United States, the Department of Defense (DoD) is a primary driver for the adoption of IPv6. Introducing IPv6 IP version 6 (IPv6) combines expanded addressing with a more efficient and feature-rich header to meet the demands for scalable networks in the future. One key benefit is that IPv6 can recreate end-to-end communications without the need for Network Address Translation (NAT) Cisco Systems currently supports IPv6 in Cisco IOS Software Release (2)T and later. IPv6 Features Large Address Space IPv6 . | IPv6 CCNA Exploration version Overview IP version 6 (IPv6) was developed to overcome the limitations of the current standard, IP version 4 (IPv4). IPv4 allows end systems to communicate and forms the foundation of the Internet as we know it today. However, one of the major shortcomings of IPv4 is its limited amount of address space. The explosion of new IP-enabled devices and the growth of undeveloped regions have fueled the need for more addresses. In the United States, the Department of Defense (DoD) is a primary driver for the adoption of IPv6. Introducing IPv6 IP version 6 (IPv6) combines expanded addressing with a more efficient and feature-rich header to meet the demands for scalable networks in the future. One key benefit is that IPv6 can recreate end-to-end communications without the need for Network Address Translation (NAT) Cisco Systems currently supports IPv6 in Cisco IOS Software Release (2)T and later. IPv6 Features Large Address Space IPv6 routers do not perform fragmentation. Instead, a discovery process determines the optimum maximum transmission unit (MTU) to use during a given session. Link-layer technologies already perform checksum and error control. Because link-layer technologies are relatively reliable, an IP header checksum is considered to be redundant. Comparing IPv4 and IPv6 Headers Flow Label: 20-bit field that allows a particular flow of traffic to be labeled. It can be used for multilayer switching techniques and faster packet-switching performance. Extension Headers: Follows the previous eight fields. The number of extension headers is not fixed, so the total length of the extension header chain is variable. Traffic class: ToS Payload Length Next Header: Tcp, Udp Hop Limit: TTL No Checksum Extension Header Extension Header IPv6 Extension Headers IPv6 Header: Basic header described in the previous figure. Hop-by-hop options header Destination options header (when the routing header is used) Routing