IPv6 address format and unicast address Configuration

Source: Internet
Author: User
Tags anycast

There are three types of IPv6 addresses: global unicast addresses (public addresses), local links (communications on the same link), and loopback addresses. No addresses are specified, A unique local address (private address) with an Ipv4 address embedded.

Anycast: (as long as one of them receives it)

Multicast: (each address must receive data)

Address Space: Leading bit

Address: the range of the first sixteen-digit Group

Allocation status: 0000 0000 0000:/80000

Unspecified address (all 0) 00ff

Return address (I .e.: 1/128)

Embedded Ipv4 address: 001x2000:/3 2000 3 ffff

Global unicast address: 1111 110x FC00:/7 FC00 FDFF

Unique local Unicast address: 1111 1110 10 FE80:/10 FE80

Local thin link address: FEBF 1111 1111 FF00:/8 FF00

Multicast address: FFFF

Some special addresses: All nodes are local (the range is restricted to nodes)

Multicast address FF01: 1 for IPv6 nodes

Multicast address of the local Ipv6 node on all links: FF02: 1 (the RA packet sent by the router is sent to this multicast address)

Multicast address of the local Ipv6 router of all nodes: FF01: 2

Multicast address of the local Ipv6 router on all links: FF02: 2

Multicast address of the local Ipv6 router of all sites: FF05: 2

The well-known multicast addresses defined in routing protocols are as follows:

Multicast address of local RIP route for all links: FF02: 9

Multicast address of the local OSPF route for all links: FF02: 5

Multicast address of the ospf dr route on all links: FF02: 6

Multicast address of the PIM router on all links: FF02: D (the local address of the site has not been abolished, instead it is a unique local address)

Global unicast address settings include:

1. manually configure the global unicast address

1. Static: manually set the IPv6 address and prefix length

2, EUI-64: manually set the prefix and length, and dynamically create Interface ID (dynamic and divided into two types: 1, automatically allocated by the router interface ID.2 generated by improved EUP-64, priority 2)

3. Unnumbered IP Address: allows the interface to use the IP addresses of other interfaces on the same device.

2. dynamic configuration 1, SLAAC: uses the ND route to advertise the message to determine the prefix and length, and the interface part is created by the EUI-64 thread.

2. DHCP6: Obtain the addressing information through related services of the DHCPv6 server.

Whether the host configured to automatically obtain the addressing information uses SLAAC or DHCPv6 depends on the configuration information in the router RA message.

The IPv6 Neighbor Discovery protocol uses the route message sent by NA to notify the prefix, prefix length, default gateway, and other information. The address generated by SLAAC must be unique.

For example, if a MAC address is 00-19-D2-8C-E0-4C and you want to allocate it to the address, the following process will be performed in SLAAC mode: 1. Send an NDP route request (it is a multicast address, with all vrouters multicast address FF02:: 2)

2. the router sends RA (the first multicast address, FF02: 1, which contains information such as the prefix and length)

3, get the prefix 2001: Db8: AAA: 1: EUI-64 interface is 02-19-D2-FF-FE-8C-E0-4C (add FFFE in the middle of the 48-bit MAC address, then flip the first byte of the seventh bit to obtain)

Global unicast address: 2001: DB8: AAAA: 1: 0219: D2FF: FE8C: E04C prefix length/64 4, NDP sends another request message, DAD (duplicate address detection)

The destination IPv6 address: 2001: DB8: AAAA: 1: 0219: D2FF: FE8C: E04C sends the NS message. If no NA message is received, the message is unique.

If the DHCP6 method is used, the host sends a DHCPv6 request to the specific multicast address FF02: 1: 2.

The local address of the local unicast link is only used for the unicast address of a single link. The uniqueness of the local address must be ensured, and the package will not be routed outside the link. The configuration methods are: 1, dynamic mode, using EUI-64 2, randomly generated interface ID 3, static mode, manual data link local address

Local link address usage: 1. The vro uses the local link address as the default gateway for the RA message they send. 2. The router running the routing protocol uses the local link address to establish the connection.

3. Dynamic Routing in the IPv6 route table uses the local link address as the next hop address.

1, dynamic mode, the use of Fe80:/64 prefix, interface ID can be randomly generated or the use of EUI-64. 2. randomly generated interface ID. For privacy issues, place other people to track the real MAC address, so use the randomly generated interface ID 3, static link local address, manual input is used to facilitate recognition or memory.

Return address: 1 unspecified address: 0

Unique local address: replace the name of the local address of the previous site. Specific purpose: Baidu knows that someone has replied: for example, you will understand that there is an enterprise intranet full-Network ipv6, the finance department and the marketing department are separated. Obviously, the finance department and the marketing department are two different subnets. The communication between the Finance Department and the Marketing Department uses a unique local address. This characteristic reflects the internal characteristics of the Organization, because they all belong to the Enterprise. The local address of the communication link between the Finance Department and the finance department or the marketing department and the marketing department reflects the characteristics of his local subnet. Let's take a look at the ipv4 classification features. Otherwise, it will be confusing.

Embedded Ipv4 address: ing Ipv4 to Ipv6

0000 0000 0000 ...... 0000 FFFF w. x. y. z

The first 80 bits are all 0, and the first 16 bits of the 32bit IPv4 are all 1, which constitute the address mapped to Ipv6.

Multicast address:

Format: FF00: 8 1111 1111 abcd efgh group ID 4bit 4bit effecbit abcd: Flag 0: Permanent multicast address 1: non-permanent multicast address efgh: the range specifies multiple ranges, including global, local organization, local site, local link, and local interface.

Multicast addresses are divided into allocated multicast addresses and requested multicast addresses.

Request multicast address: automatically created by using the specific ing of the device Unicast address and the prefix FF02: 0: 0: 0: 0: 1: FF00:/104 of the requested node multicast address.

The request multicast address is usually used to implement two IPv6 mechanisms (both part of the NDP): Address Resolution: the Ipv6 device sends a neighbor request message to the multicast address of the Request node, to learn the link layer addresses of devices on the same link.

DAD: DAD allows devices to verify the uniqueness of Unicast (or renbo) addresses created through SLAAC on the link. The device sends neighbor request information to its own request multicast address to determine whether there are other devices on the link using the address change.

Generation Method: copy the 24-bit-low Unicast address to the 24-bit-low multicast address, and generate a 104-bit request node multicast address based on its prefix FF02: 1: FF. The multicast address of the Request node is automatically created for each Unicast address on the device.

Anycast address: it is still in the trial stage.

Blog: http://blog.chinaunix.net/uid-23117778-id-3804890.html

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