ZyXEL Communications VMG5313-B10A/ VMG5313-B30A User Manual

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 Appendix C IPv6
VMG5313-B10A/-B30A Series User’s Guide
377
Subnet Masking
Both an IPv6 address and IPv6 subnet mask compose of 128-bit binary digits, which are divided 
into eight 16-bit blocks and written in hexadecimal notation. Hexadecimal uses four bits for each 
character (1 ~ 10, A ~ F). Each block’s 16 bits are then represented by four hexadecimal 
characters. For example, FFFF:FFFF:FFFF:FFFF:FC00:0000:0000:0000.
Interface ID
In IPv6, an interface ID is a 64-bit identifier. It identifies a physical interface (for example, an 
Ethernet port) or a virtual interface (for example, the management IP address for a VLAN). One 
interface should have a unique interface ID.
EUI-64
The EUI-64 (Extended Unique Identifier) defined by the IEEE (Institute of Electrical and Electronics 
Engineers) is an interface ID format designed to adapt with IPv6. It is derived from the 48-bit (6-
byte) Ethernet MAC address as shown next. EUI-64 inserts the hex digits fffe between the third and 
fourth bytes of the MAC address and complements the seventh bit of the first byte of the MAC 
address. See the following example. 
Identity Association
An Identity Association (IA) is a collection of addresses assigned to a DHCP client, through which 
the server and client can manage a set of related IP addresses. Each IA must be associated with 
exactly one interface. The DHCP client uses the IA assigned to an interface to obtain configuration 
from a DHCP server for that interface. Each IA consists of a unique IAID and associated IP 
information.
The IA type is the type of address in the IA. Each IA holds one type of address. IA_NA means an 
identity association for non-temporary addresses and IA_TA is an identity association for temporary 
addresses. An IA_NA option contains the T1 and T2 fields, but an IA_TA option does not. The 
DHCPv6 server uses T1 and T2 to control the time at which the client contacts with the server to 
extend the lifetimes on any addresses in the IA_NA before the lifetimes expire. After T1, the client 
sends the server (S1) (from which the addresses in the IA_NA were obtained) a Renew message. If 
FF08:0:0:0:0:0:0:0
FF09:0:0:0:0:0:0:0
FF0A:0:0:0:0:0:0:0
FF0B:0:0:0:0:0:0:0
FF0C:0:0:0:0:0:0:0
FF0D:0:0:0:0:0:0:0
FF0E:0:0:0:0:0:0:0
FF0F:0:0:0:0:0:0:0
Table 155   
Reserved Multicast Address (continued)
MULTICAST ADDRESS
                MAC
00
: 13
: 49
: 12
: 34
: 56
     EUI-64
0
2
: 13
: 49
: FF
: FE
: 12
: 34
: 56