Idle talk IPv6 address

 

A huge IPv6 address space ensures that all cats and dogs have unique addresses.

The primary motivation of IPv6 is to meet the needs of the world's unique address. The number of IPv6 addresses is four times the number of IPv4 addresses. One is 32 bits and the other is 128 bits. IPv6 provides a unique address for each network device on the planet. IPv6 addresses are globally unique and make global accessibility and end-to-end security of network devices possible. This feature is critical to some applications and services. In addition, the flexibility of IPv6 address space reduces the need for private addresses and NAT. Therefore, IPv6 eliminates the need for special processing on edge routers for new application protocols.

 

IPv6Address format

The IPv6 address uses a series of 16-bit hexadecimal fields separated by colons in the format of x: x. The following is an example of two IPv6 addresses:

2001: DB8: 7654: 3210: FEDC: BA98: 7654: 3210

2001: DB8: 0: 0: 8: 800: 200C: running

It is common to include a zero consecutive hexadecimal field in an IPv6 address. To make the IPv6 address look less disturbing, two colons (: :) can be used to compress the hexadecimal fields that are continuously zero at the beginning and end of an IPv6 address. The two colons can be used as part of the IPv6 address variable when the continuous hexadecimal field is expressed as zero. You can configure multiple IPv6 addresses on each port,Only one local link is allowed.. Note: The two colons (: :) can only be used once in an IPv6 address, and represent the longest continuous zero hexadecimal field. The hexadecimal letters of IPv6 addresses are case-insensitive.

 

IPv6Address type	Preferred format	Compression format
Unicast	2001: 0: 0: 0: DB8: 800: 200C: running	2001: DB8: 800: 200C: running
Multicast	FF01:0: 0: 0: 0: 0: 101	Ff01:: 101
Local Loop	0: 0: 0: 0: 0: 0: 0: 1	: 1
Undetermined	0: 0: 0: 0: 0: 0: 0: 0	::

 

The local loop address is used to send IPv6 packets to a node, which is equivalent to the local loop address 127.0.0.0 of IPv4. Do not forget yourself at any time. If the IPv6 address is not specified, the IPv6 address is missing. For example, a newly initialized node of an IPv6 network can use an uncertain address as the source address to send data packets until it receives the IPv6 address.

An IPv6 address prefix, in the format of IPv6 prefix/prefix length, is used to represent the entire address space. 2001: DB8: 8086: 6502:/32.

 

IPv6Address type: unicast

An IPv6 unicast address is the identifier of a single node interface. When a packet is sent to a unicast address, it is sent to the port identified by that address. There are four types of IPv6 unicast addresses:

1.Aggregate global addresses

An aggregated global address is an IPv6 address with an aggregated global unicast prefix. Aggregated global unicast addresses use a strict combination of Route prefixes to limit the number of routes in the global route table. The aggregated global address is used for the connection that is aggregated to the ISP through the Organization.

Aggregates Global IPv6 addresses throughGlobal route prefix, subnet ID and interface (host part) IDDefinition. Except for addresses starting with 000, all global unicast addresses have 64-bit interface IDs. IPv6 global unicast address allocation uses addresses starting with 001(2000:/3)

Addresses with prefix 2000:/3 (001) and E000:/3 (111) must have a 64-bit interface identifier in the extended universal identifier (EUI)-64 format. IANA assigns an IPv6 address to the registry in the range of 2000:/16.

Aggregate global addresses generally include48-bit global route prefix and 16-bit subnet IDOr station-level aggregation (SLA ). In the IPv6 aggregated global unicast address format file (RFC 2374), the global route prefix includes two other hierarchical fields called top-level aggregators (TLA) and secondary aggregators (NLA ). Because these two items are out of date, they are no longer repeated.

A 16-bit subnet field is called a subnet ID, which allows individual organizations to create their own local address levels and identify subnets. The subnet ID is similar to the subnet ID in IPv4. In addition to an IPv6 subnet ID, an organization can support up to 65535 subnets.

Interface ID used to identify the port in the Link. The port must be unique relative to the link. In many cases, the interface ID may be the same as or based on an interface link layer address. The interface IDs of the aggregated global unicast addresses and other IPv6 address types must be 64-bit.

IEEE EUI-64 address represents a new standard for network interface addressing. The company ID is still 24-bit long, but the extended ID is 40-bit, creating a larger address space for the network adapter manufacturer. The EUI-64 address uses U/L and I/G bits in the same way as the IEEE 802 address.

An Interface ID is built in one of the following ways in the modified EUI-64 format:

1. In all IEEE 802 interface types (such as Internet and FDDI interfaces ),The first three bytes (24 bits) use the OUI part in the MAC address, the fourth and fifth bits use a fixed value of FFFE, and the last three bytes use the second half of the MAC address.SetThe U/L bit value (the first byte, the seventh bit) is 0 or 1.0, which indicates the local management identifier, and 1 indicates the globally unique IPv6 interface identifier.

2. For other interface types (such as serial port, local loop, ATM, frame relay, and tunnel interface types-except for IPv6 overlay tunnel), the interface ID is the same as that of IEEE 802.

3. Tunnel interface type. The interface ID uses the IPv4 address of the tunnel interface, and all the 32-bit high values are 0.

If the non-IEEE interface type is used in a vro, the production sequence of the Local Link IPv6 address in the vro interface is as follows:

1. Router consultationMAC address.

2. If no MAC address is available in the vro,Vro serial numberUsed to form a local link address.

3. If the vro serial number cannot be used to form a local link address, the vro uses message digest algorithm 5 (MD5) to determine the vromac MAC address through the vro host name.

2.Local link address

The local link address is an IPv6 unicast address that can be automatically configured on any port through the local link prefix FE80:/10 and EUI-64 format interface identifier. The local link address is used in the process of Neighbor Discovery protocol and stateless automatic configuration. Nodes on a local link can communicate with each other using the local link address.

3. IPv4IPv6 address compatibility

An IPv4-compatible IPv6 address is an IPv6 unicast address. The 96-bit high is 0, and the 32-bit low is an IPv4 address. The IPv6 address format compatible with IPv4 addresses is A. B .C.D.

4.Unique local address

The unique local address is an IPv6 unicast address, which is globally unique and used for local communication. It cannot be routed over a wan. It can only be routed in one restricted area.

 

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