ZyXEL nbg-4615 사용자 가이드

다운로드
페이지 392
NBG4615 User’s Guide
149
C
H A P T E R
 
 1 5  
IPv6
15.1  Overview 
IPv6 (Internet Protocol version 6), is designed to enhance IP address size and 
features. The increase in IPv6 address size to 128 bits (from the 32-bit IPv4 
address) allows up to 3.4 x 1038 IP addresses. 
• See 
 for more information on IPv6.
15.1.1  What You Need to Know
IPv6 Addressing
The 128-bit IPv6 address is written as eight 16-bit hexadecimal blocks separated 
by colons (:). This is an example IPv6 address 
2001:0db8:1a2b:0015:0000:0000:1a2f:0000
.
IPv6 addresses can be abbreviated in two ways:
• Leading zeros in a block can be omitted. So 
2001:0db8:1a2b:0015:0000:0000:1a2f:0000
 can be written as 
2001:db8:1a2b:15:0:0:1a2f:0
• Any number of consecutive blocks of zeros can be replaced by a double colon. A 
double colon can only appear once in an IPv6 address. So 
2001:0db8:0000:0000:1a2f:0000:0000:0015
 can be written as 
2001:0db8::1a2f:0000:0000:0015
, 2001:0db8:0000:0000:1a2f::0015, 
2001:db8::1a2f:0:0:15
 or 2001:db8:0:0:1a2f::15.
IPv6 Prefix and Prefix Length
Similar to an IPv4 subnet mask, IPv6 uses an address prefix to represent the 
network address. An IPv6 prefix length specifies how many most significant bits 
(start from the left) in the address compose the network address. The prefix 
length is written as “/x” where x is a number. For example, 
2001:db8:1a2b:15::1a2f:0/32
means that the first 32 bits (2001:db8) is the subnet prefix.