6. Basic Address Types
•
1.
2.
3.
Unicast
Address of a single interface
Delivery to single interface
for one-to-one communication
•
1.
2.
3.
Multicast
Address of a set of interfaces
Delivery to all interfaces in the set
for one-to-many communication
•
1.
2.
3.
4.
Anycast
Address of a set of interfaces
Delivery to a single interface in the set
for one-to-nearest communication
Nearest is defined as being closest in term of routing distance
• Broadcast don’t use anymore
6
12. 由 MAC Address 產生 Interface
ID
1.
2.
3.
4.
First three octets of MAC is Company-ID
Last three octets of MAC is Node-ID
將 FFFE 置入 Company ID 與 Node-ID 間
Company ID 2 進位表示法之第 7 碼為 Univeral/LocalBit ，設為 1 表示 Global Scope
如 : MAC Address 為 00-C0-3F-BB-93-91 ，則
1. Company ID 為 00-C0-3F, Node ID 為 BB-93-91
2. 00-C0-3F-FF-FE-BB-93-91
3. Company ID 2 進位表示法為 00000000 11000000
00111111
4. 將第 7bit 改為 1 ，為 00000010 11000000 001111111
5. 重組為 02-C0-3F
6. Interface ID 為 2C0:3FFF:FEBB:9391
12
15. Link-Local Address
• Meaningful only in a single link zone, and may be re-used
on other links
• Link-local addresses for use during auto-configuration
and when no routers are present
• Required for Neighbor Discovery process, always
automatically configuration
• An IPv6 router never forwards link-local traffic beyond
the link
• Prefix= FE80::/64
1111111010
10 bits
圖來自中華電信研究所
0
interface ID
54 bits
64 bits
16
16. Unique-Local Address
•
•
•
•
•
•
同一個 Unique local address 不能重複使用
等同於 IPv4 private address space
取代原有定義的 IPv6 Site-Local Addresses
L flag 代表 assignment policy. 目前只有 L=1 被使用
Global ID 長度 40-bit, 並隨機產生 .
Prefix= FC00::/7
L=1 表示 Local
L=0 保留中
1111110 L
7 bits
Global ID
subnet ID
40 bits
16 bits
interface ID
64 bits
17
圖來自中華電信研究所
