There are three aspects of IPv6 technical advantages

When talking about IPv6 technology, we always compare it with IPv4. So what is the praise of IPv6 technology? Now let's summarize the advantages of IPv6 technology. First, let's introduce our topic today from the issue of ultra-long data transmission.

How does IPv6 technology solve the problem of ultra-long data transmission?

IPv6 requires that each link on the Internet has a maximum transmission unit (MTU) of 1280 or more eight-bit groups ). Links that cannot transmit 1280 eight-bit groups within a segment must provide a segmentation and restructuring mechanism in the IPv6 protocol based on the link conditions. A link with MTU configurable. For example, a PPP link must be configured as an MTU with at least 1280 eight-bit groups. To send a packet greater than the MTU path, the node can use the IPv6 segment header, segment the package at the source node and reorganize the package at the target node.

In IPv6 communication, how can the source node find the maximum transmission unit to the target node?

RFC1981 describes a method for dynamically discovering the maximum transmission unit PMTU of a path. The basic idea is that the source node initially assumes that the PMTU of a path to the target node is the known MTU of the first hop of the path. If any package sent to this path is too large to be forwarded by some nodes in the path, those nodes will discard these packages and send them back to the ICMPv6 package for too many messages. After receiving such a message, the source node should reduce the MTU value of the hop compressed by the MTU value reported in the packet is too large to be the PMTU assumed by this path.

When the estimated PMTU value of the node is smaller than or equal to the actual PMTU, the MTU discovery process ends. Note that in this process, the cycle of "sending packets-receiving packets with too many messages" may be repeated multiple times, because there may always be a smaller MTU link on the path. The node can also terminate the discovery process by stopping the packet that is larger than the MTU, the minimum link of the IPv6 protocol technology.

What are the new features of IPv6 in routing?

IPv6 uses a clustering mechanism to define a flexible Hierarchical Addressing and routing structure. Multiple networks at the same level are represented as a unified network prefix in the upper-layer router, this can significantly reduce the route table items that must be maintained by the router. Ideally, a core backbone network router must maintain no more than 8192 entries. This greatly reduces router routing and storage overhead.

Another feature of IPv6 technology is the provision of data stream tags, that is, traffic identification. A vro can identify data packets belonging to a specific traffic, and this information is recorded when it is received for the first time. After the vro receives the same traffic data packet next time, the vro uses the identified data packet, you do not need to check the path selection table, which reduces the data processing time.

The destination address is the information package route of a multicast address. In IPv6, the problem of multi-point transmission routing is similar to that in IPv4, but its functions are enhanced and become part of ICMPv6 and OSPFv6, rather than the separate protocol in IPv4, this has become a part of IPv6. To route multi-point transfer information packets, a distributed tree multi-point transfer tree is created in IPv6) to all members in the group.

What routing protocols are available in IPv6?

IPv6 mainly uses three Routing protocols: RIPv6Routing Information Protocol, Routing Information Protocol), OSPFv6Open Shortest Path First, Open Shortest Path First, Open Shortest Path First) and IDRPv2Inter-Domain Routing Protocol, Inter-Domain Routing Protocol) as well as the possibility that the source image can be used in the source image.

RIPv6 is a RIP version that can be used together with IPv6. The updated RIP can receive 128-bit addresses without adding new features and removing the prefix length. The reason for this choice is to keep RIPv6 simple so that it can be implemented on very simple devices.

OSPFv6 is an OSPF version that can be used for IPv6. It is also an internal gateway routing protocol (IGP) recommended by IPv6 technology. As a standard implementation of all router manufacturers, it is suitable for large-scale networks. As an OSPF update, OSPFv6 allows you to transmit a new 128-bit address and the relevant prefix length. In OSPFv6, the region is defined as a 128-bit address.

IDRP is an external Gateway Routing Protocol (EGP) used together with IPv6. IDRP is a path vector protocol and is designed in the OSI structure in the connectionless network protocol CLNP, ISO 8473, from the BGP-4 as EGP on the Internet, the IDRP version suitable for joint use with IPv6 is IDRPv2.

What are the features of IPv6 technology in supporting multicast?

IPv6 enhances the multicast function, which can pass information to all hosts registered to receive the message. The multicast function can be used to transmit data to a large number of users at the same time. The transfer process only occupies public or private bandwidth overhead and does not waste bandwidth broadcast throughout the network.

The "flag" is added to the IPv6 multicast function to distinguish between permanent and temporary addresses, which is more conducive to the implementation of the multicast function. IPv6 also includes some features that limit the delivery range of multicast messages. In this way, multicast messages can be confined to a specific location, region, company, or other agreed scope, this reduces bandwidth usage and provides security. The significance of multicast is that only users who join the corresponding multicast group can receive the information sent to the group, which is especially important for sending video programs, the channel concept in analog TV can be completely replaced by the multicast group concept. In addition, the multicast group scope can include nodes at any location in the global address space of the same region network, the same organization network, or even the IPv6 protocol technology, this provides more flexibility for the network multimedia information service.