ZyXEL Communications ZyWall USG20-VPN, User Manual

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Chapter 9 Interfaces
USG20(W)-VPN Series User’s Guide
144
Note: * You cannot set up a PPP interface, virtual Ethernet interface or virtual VLAN
interface if the underlying interface is a member of a bridge. You also cannot add
an Ethernet interface or VLAN interface to a bridge if the member interface has a
virtual interface or PPP interface on top of it.
IPv6 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 10
38
IP
addresses.
IPv6 Addressing
An 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
.
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
PPP interface Ethernet interface*
VLAN interface*
bridge interface
WAN1, WAN2, OPT*
virtual interface
(virtual Ethernet interface)
(virtual VLAN interface)
(virtual bridge interface)
Ethernet interface*
VLAN interface*
bridge interface
trunk Ethernet interface
Cellular interface
VLAN interface
bridge interface
PPP interface
Table 61
Relationships Between Different Types of Interfaces (continued)
INTERFACE REQUIRED PORT / INTERFACE